CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose

CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose Yannick Laurent Thal, Marcel Optiz, Raya Serger, Laura Kluener, and 9 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7722326/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Nov, 2025 Read the published version in Clinical Neuroradiology → Version 1 posted You are reading this latest preprint version Abstract Purpose Spinal muscular atrophy (SMA) is a rare neuromuscular disease treated with intrathecal nusinersen. In patients with complex spinal anatomy or spinal instrumentation, repeated lumbar punctures can be challenging. CT guidance is a valuable alternative. This study evaluated feasibility, safety, and radiation exposure of CT-guided nusinersen administration in SMA. Methods In this retrospective single-center study, 458 CT-guided nusinersen injections performed in 44 SMA patients between October 2017 and August 2024 were analyzed. Technical success, complications, procedure times, and radiation exposure were assessed between subgroups. Results Overall technical success was 98.3% (449/458). Success rates were slightly lower in patients with dorsal spondylodesis (97.1% vs. 98.8%, p=0.311). Complications occurred in 1.1% (5/458). Patients with spondylodesis had significantly longer puncture (median 11.9 vs. 10.3 min, p=0.0031) and procedure durations (16.3 vs. 14.0 min, p=0.0028) and higher radiation doses (CTDIvol 9.68 vs. 7.24 mGy, DLP 142 vs. 105 mGy·cm, effective dose 2.22 vs. 1.74 mSv; all p<0.0001). Failed or complicated procedures were linked to prolonged durations (p<0.0001) and higher radiation exposure. Needle repositioning was more frequent in spondylodesis, failed, and complicated cases, and correlated with duration and radiation dose. Technical success was independent of patient positioning. Conclusion CT-guided lumbar puncture for intrathecal nusinersen injection is a safe and effective technique, even in patients with complex spinal anatomy. Dorsal spondylodesis increases complexity, reflected by longer durations, more repositioning, and higher radiation exposure. Tailored puncture level selection, optimized positioning, and dose-reduction strategies are essential for high success rates and minimizing radiation burden in long-term SMA therapy. Spinal muscular atrophy (SMA) Nusinersen Intrathecal drug administration CT-guided lumbar puncture Radiation exposure Dose optimization Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Spinal muscular atrophy (SMA) is a rare autosomal recessive motor neuron disease characterized by progressive degeneration of motor neurons in the anterior horn of the spinal cord [ 1 , 2 ]. Clinically, it manifests with generalized muscle hypotonia and atrophy, which can present from early infancy to adulthood, depending on the disease subtype [ 3 , 4 ]. The underlying cause is a mutation in the SMN1 gene, while disease severity correlates with the number of SMN2 gene copies [ 5 , 6 , 7 ]. With the approval of nusinersen in 2017, the first disease-modifying therapy became available. It enhances the alternative splicing of SMN2 transcripts, thereby increasing production of functional SMN protein [ 8 , 9 ]. The clinical benefits of nusinersen have been well demonstrated in both pediatric and adult populations, leading to widespread adoption as a standard of care [ 10 , 11 ]. This is further supported by a recent systematic review and meta-analysis in adolescents and adults, which confirmed that nusinersen treatment leads to stabilization or improvement of motor function across a broad spectrum of SMA patients [ 12 ]. However, its mode of administration—repeated intrathecal injection—poses considerable logistical and technical challenges, particularly in patients with severe scoliosis, complex spinal anatomy, or prior spinal instrumentation [ 13 , 14 , 15 ]. Image guidance such as fluoroscopy or ultrasound has been explored, but often prove insufficient in complex cases or in centers lacking specific expertise [ 16 ]. CT-guided lumbar puncture, by contrast, provides high-resolution anatomical visualization and has emerged as a safe and effective technique for intrathecal drug administration in complex cases [ 16 , 17 ]. Prior case series and institutional experiences have demonstrated feasibility and safety; however, large-scale data on long-term implementation, technical success rates, and cumulative radiation exposure are still limited, especially in adult and surgically pretreated populations [ 13 ]. The aim of this study was to analyze the technical feasibility, safety profile, and radiation exposure of CT-guided intrathecal nusinersen administration in a large cohort of patients with SMA. In addition, the impact of anatomical factors—in particular dorsal spondylodesis—as well as patient positioning and puncture level were assessed. Material and Methods Study Design and Cohort This retrospective, single-center observational study was approved by the local ethics committee and the requirement for informed consent was waived. All CT-guided procedures performed between October 2017 and August 2024 were reviewed. The study cohort selection process is shown in Fig. 1 . All procedures unrelated to nusinersen injections or in patients lacking a confirmed diagnosis of SMA were excluded. Procedural Technique All nusinersen injections were performed under CT guidance using one of the following scanners: SOMATOM Definition AS+, SOMATOM Definition Flash, SOMATOM X.ceed, or NAEOTOM Alpha. CT scans were acquired in a step-and-shot technique. For image guidance, a single axial sequence was reconstructed in three slices with 3-mm thickness, using comparable technical parameters across all scanners. The median tube voltage was 115 kV (IQR 110–120) and the median tube current time product was 87 mAs (IQR 69–128). All procedures were preceded by thorough preparation, including pre-procedural planning, imaging, laboratory testing, and written informed consent. Patient positioning was adapted to individual anatomical and clinical considerations, with punctures typically performed in the lateral or prone position. The puncture level was selected based on anatomical feasibility and any prior surgical interventions (e.g., spondylodesis, sclerotic changes, osteophytes). All punctures were performed by board-certified neuroradiologists under standardized conditions. A consistent protocol regarding antiseptic preparation and needle type was followed throughout to ensure procedural uniformity and minimize variability. Nusinersen administration was carried out by the treating neurologists. Procedural documentation, including time stamps (start, end, needle insertion), was recorded in the RIS (Radiology Information System) and PACS (Picture Archiving and Communication System). Technical success was defined as successful intrathecal needle placement with complete administration of nusinersen. Complications were systematically recorded both during the procedure and throughout the postprocedural hospital stay until discharge. All adverse events were evaluated based on clinical documentation and imaging findings. Data Collection and Evaluation The following parameters were recorded: demographic data, SMA subtype, patient positioning, puncture level, presence of dorsal spondylodesis, technical success, number of repositioning attempts, complications during the procedure and until discharge. The total intervention time was defined as the duration from acquisition of the planning scan to the documented end of the procedure. Puncture duration was defined as the time between the first attempt at needle placement and successful intrathecal nusinersen injection. 9 cases were excluded from time-based analysis, due to incomplete documentation or procedure abortion. Radiation Exposure Assessment Radiation exposure was documented for each procedure using the parameters CTDIvol (volumetric computed tomography dose index) in mGy, dose-length product (DLP) in mGy·cm, and effective dose in mSv. The effective dose for CT-guided injections was calculated according to ICRP (International Commission on Radiological Protection) Publication 103 [ 18 ]. In 11 procedures, radiation dose data were incomplete or missing and were therefore excluded from at least one dose-related analysis. Statistical analysis Statistical analysis was performed using GraphPad Prism (version 10.5.0; GraphPad Software, San Diego, CA, USA). Categorical variables (e.g., technical success, complications) were analyzed using Fisher’s exact test or Chi-squared test, as appropriate. Continuous variables were non-normally distributed and are expressed as medians with interquartile ranges (IQR). Two-group comparisons (e.g., spondylodesis vs. no spondylodesis, successful vs. failed procedures) were carried out using the Mann–Whitney U test. Comparisons across more than two groups (e.g., puncture level, patient positioning) were assessed with the Kruskal–Wallis test followed, where significant, by Dunn’s multiple comparisons post-hoc analysis. Correlations between number of needle repositioning attempts, procedural durations, and radiation dose parameters were evaluated using Spearman’s rank correlation. Statistical significance was defined as p < 0.05. Results Out of 1,074 CT-guided spinal interventions, 616 procedures in 517 patients were excluded because they were either unrelated to nusinersen injections or lacked a confirmed diagnosis of SMA (Fig. 1 ). The study cohort comprised 458 CT-guided procedures in 44 patients with confirmed SMA. The median age was 31 years (IQR 25–44 years, range 14–58 years). 21 (47.7%) of patients were female. SMA subtype distribution included type 1 in 6.8% (3/44), type 2 in 63.6% (28/44) and type 3 in 29.5% (13/44). Dorsal spondylodesis was present in 47.7% (21/44). A summary of demographic and clinical characteristics is presented in Table 1 . Technical Success 449 out of 458 procedures were technically successful, corresponding to an overall technical success rate of 98.3%. Among patients with dorsal spondylodesis, the technical success rate was 97.1% (202/208), compared to 98.8% (247/250) in patients without dorsal spondylodesis (p = 0.311). A detailed comparison of technical success rates and procedure times is shown in Table 2 . Notably, 66% (6/9) failed procedures occurred in patients with dorsal spondylodesis. Figure 2 illustrates the increased technical complexity of CT-guided intrathecal nusinersen administration in patients with dorsal spondylodesis compared to those without spinal instrumentation. Complications Periprocedural complications occurred in 1.1% (5/458) and included 3 cases of postprocedural pain, 1 needle tract hematoma, and 1 retroperitoneal hematoma (Table 3 ). All complications were transient and without long-term sequelae. Complications occurred more frequently in patients with dorsal spondylodesis (4/203; 1.97%) compared to those without (1/255; 0.39%), although this difference did not reach statistical significance (p = 0.176). Procedures with complications or technical failure were associated with significantly prolonged procedure and puncture durations (Table 4 ). Needle Repositioning The median number of repositioning attempts across all 458 procedures was 0 (range 0–5), indicating that most procedures were performed without needle repositioning. Although the median number of repositioning attempts was 0 in both groups, procedures in patients with dorsal spondylodesis required repositioning more frequently overall, resulting in a statistically significant difference compared to those without spondylodesis (p = 0.012). Furthermore, the five procedures with complications required significantly more repositioning attempts (median 1, range 0–4) than those without (median 0; p < 0.0001). In the nine technically unsuccessful procedures, the median number of repositioning attempts was 1 (range 0–5), which was significantly higher compared to successful procedures (median 0; p < 0.0001). These findings suggest that increased procedural complexity—due to anatomical challenges or difficult access—was associated with a higher need for repositioning attempts. Figure 3 illustrates the distribution of the number of repositionings, stratified by presence of spinal fusion, procedural success, and occurrence of complications. The number of needle repositioning attempts correlated significantly with puncture duration (Spearman r = 0.34, p < 0.0001), procedure duration (r = 0.34, p < 0.0001), and radiation exposure parameters including CTDIvol (r = 0.16, p = 0.0008), DLP (r = 0.21, p < 0.0001), and effective dose (r = 0.23, p < 0.0001), indicating increased complexity and resource utilization in procedures requiring multiple needle adjustments. Patient Positioning In the prone position, 97.7% (43/44) of procedures were successful. In the left lateral position 97.9% (228/233) and in the right lateral position 98.2% (162/165) were successful. In addition, the technical success rate was 100% (5/5) in interventions in a combined right lateral/prone position and 100% (1/1) in a left lateral/prone position. Detailed results are presented in Table 5 . Patient positioning (prone, left lateral, right lateral, or combined) had no significant effect on technical success rates (p > 0.999). While patient positioning had no significant effect on technical success, it was significantly associated with puncture duration (p = 0.005). Median puncture times were 10.8 min (IQR 7.7–15.1) in right lateral, 7.3 min (IQR 6.2–8.8) in combined positions, 11.2 min (IQR 7.5–16.9) in left lateral, and 11.9 min (IQR 10.2–23.9) in prone position, with post-hoc analysis showing a significantly shorter duration in combined vs. prone positioning (p = 0.0044). Radiation dose parameters varied significantly by patient positioning. Median CTDIvol was highest in the prone position (11.52 mGy), followed by right lateral (8.97 mGy), left lateral (8.35 mGy), and lowest in the combined position (4.17 mGy; p < 0.0001). DLP showed a similar pattern, with medians of 168.9 mGy·cm (prone), 112.5 mGy·cm (right lateral), 127.9 mGy·cm (left lateral), and 51.4 mGy·cm (p = 0.0001). Effective dose was also highest in prone position (2.45 mSv) and lowest in combined position (1.17 mSv; p = 0.0143). Post-hoc analysis revealed that the combined position consistently yielded significantly lower radiation doses compared to other positions, whereas no significant differences were found between prone, left lateral, and right lateral positions. Patient positioning (prone, left lateral, right lateral, or combined) had no significant effect on the number of needle repositioning attempts (Kruskal–Wallis p = 0.178; Dunn’s multiple comparisons: all adjusted p > 0.23). Puncture Levels Puncture level selection was based on individual anatomy and any pre-existing surgical conditions, such as dorsal spondylodesis. A total of 458 puncture attempts were performed. The most frequently chosen puncture levels were L5/S1 (49.1%, 225/225; technical success rate: 100%), L4/5 (38.6%, 175/177; 98.9%), and L3/4 (3.3%, 14/15; 93.3%). Pairwise comparison revealed a significantly higher technical success rate for L5/S1 compared to L3/4 (p = 0.024), whereas no significant differences were observed between L5/S1 and L4/5 (p = 0.234) or between L4/5 and L3/4 (p = 0.265). Puncture duration did not differ significantly between the puncture levels L5/S1, L4/5, and L3/4 (Kruskal–Wallis test, p = 0.705; all post-hoc comparisons non-significant). Procedure and Puncture Duration The median puncture duration for all procedures was 11.1 minutes (IQR 7.7–16.2 minutes, range 1.6–96.6 minutes), and the median total procedure duration was 14.8 minutes (IQR 10.9–20.8 minutes, range 5.1–134.1 minutes). In patients with dorsal spondylodesis, median puncture duration was 11.9 minutes (IQR 9.1–17.6 minutes, range: 2.8–96.6 minutes) and the procedure duration was 16.3 minutes (IQR 12.5–22.1 minutes, range: 7.4–102.9 minutes). In patients without dorsal spondylodesis, these durations were 10.3 minutes (IQR 7.2–15.3, range: 1.6–76.0 minutes) and 14.0 minutes (IQR 10.4–20.6, range: 5.1–134.1 minutes), respectively. These differences were statistically significant (puncture duration: p = 0.0031; procedure duration: p = 0.0028), indicating greater procedural complexity in the spinal fusion group. In interventions with complications, the puncture duration was 55.8 minutes (IQR 55.1–76, range: 20.9–95.7 minutes) and the procedure duration was 59.7 minutes (IQR 59.1–81.9, range: 41.7–102.9 minutes). These differences were statistically significant for both puncture and procedure duration (p < 0.0001). In 8 of the 9 technically unsuccessful procedures with complete documentation, the median puncture duration was 52.2 min (IQR: 33.4–65.8; range: 18.4–96.6), and the total procedure duration was 58.4 min (IQR: 45.9–69.7; range: 22.2–102.9), both significantly longer than in successful interventions (puncture: 11.1 min; procedure: 14.8 min; p < 0.0001). Figure 4 illustrates the duration of procedure and puncture by technical outcome and complication status. Radiation Exposure The median CTDIvol of the 447 analyzed procedures was 8.67 mGy (IQR: 5.76–13.62), the median DLP was 121 mGy·cm (IQR: 75–218), and the median effective dose was 2.02 mSv (IQR: 1.35–3.17). In patients with dorsal spondylodesis, the CTDIvol was 9.68 mGy (IQR: 7.53–13.92), the DLP was 142 mGy·cm (IQR: 95–240) and the effective dose was 2.22 mSv (IQR: 1.60–3.25). In patients without dorsal spondylodesis, lower values were recorded: CTDIvol 7.24 mGy (IQR: 4.12–12.64), DLP 105 mGy·cm (IQR: 59–191) and effective dose 1.74 mSv (IQR: 1.08–3.04). All three radiation dose parameters were significantly higher in patients with dorsal spondylodesis: CTDIvol (median 9.68 mGy vs. 7.24 mGy), DLP (142 vs. 105 mGy·cm), and effective dose (2.22 vs. 1.74 mSv; all p < 0.0001, Fig. 5 ). These differences underline the increased technical demands and prolonged scan durations in this patient subgroup. In procedures with complications, radiation exposure was higher: CTDIvol 9.78 mGy (IQR: 5.08–22.50), DLP 414 mGy·cm (IQR: 212–447) and effective dose 3.82 mSv (IQR: 3.45–4.25). Although CTDIvol did not differ significantly between procedures with and without complications (median 9.78 mGy vs. 8.67 mGy; p = 0.608), both DLP (414.4 vs. 121.0 mGy·cm; p = 0.040) and effective dose (3.82 vs. 2.01 mSv; p = 0.030) were significantly higher in procedures with complications, likely reflecting the need for additional scan acquisitions in technically demanding cases. In unsuccessful procedures, radiation exposure was highest: CTDIvol 17.8 mGy (IQR: 8.58–30.87), DLP 414 mGy·cm (IQR: 119–599), and effective dose 4.25 mSv (IQR: 2.54–7.69); all values were significantly higher compared to successful procedures (CTDIvol 17.8 mGy vs. 8.7 mGy, p = 0.047; DLP 414 mGy·cm vs. 121 mGy·cm, p = 0.014; effective dose 4.25 mSv vs. 2.02 mSv, p = 0.002). A summary of radiation exposure parameters across patient subgroups is provided in Table 6 . Discussion This study provides a comprehensive evaluation of CT-guided intrathecal nusinersen administration in adolescent and adult patients with SMA in a routine clinical setting. With a high technical success rate of 98.3%, it confirms the feasibility and reliability of CT-guided lumbar puncture—even under complex anatomical conditions such as dorsal spinal fusion [ 19 , 20 ]. The observed differences in technical success, duration, and radiation exposure between patients with and without spinal instrumentation reflect the increased technical demands in surgically altered anatomy, which was also evident in the higher repositioning rates observed in this subgroup [ 21 , 22 ]. These findings are consistent with previous reports [ 23 ], which also demonstrated higher effective doses in patients with dorsal spondylodesis compared to those without. Our study extends these observations by confirming them in a substantially larger cohort and by providing a more detailed analysis of procedural duration and technical outcomes. Although patients with dorsal spondylodesis demonstrated a slightly lower technical success rate and significantly longer procedure and puncture durations, the outcomes remained favorable overall. Nonetheless, the technical success rate of over 97% in the fusion subgroup underlines the robustness of the CT-guided approach. These findings highlight that even challenging cases can be managed safely and effectively with proper planning and technique [ 24 ]. Importantly, procedures associated with complications or technical failure showed significantly prolonged durations and markedly increased radiation exposure. These findings underscore the importance of minimizing procedure complexity through individualized preparation and image-based planning, particularly in patients with altered spinal anatomy or previous surgical interventions [ 21 ]. The low overall complication rate of 1.1%, with no long-term sequelae, further supports the safety of this method and is consistent with previously published data [ 25 , 26 , 27 ]. The predominance of complications in the fusion group is noteworthy and may serve as a reminder for heightened procedural awareness in this subgroup. Importantly, both failed and complicated procedures were associated with longer durations and markedly increased radiation doses—underscoring the importance of careful planning, patient-specific protocol optimization, and dose-saving strategies. Patient positioning did not appear to have a substantial impact on technical success rates. This suggests that procedural positioning can be tailored flexibly based on anatomical and clinical considerations, without compromising safety or effectiveness. The puncture level L5/S1 proved to be the most accessible and reliable, achieving a 100% success rate. In contrast, alternative or repeated punctures at other levels were more commonly associated with technical failure, particularly in the presence of prior instrumentation. Compared to alternative imaging modalities such as ultrasound or fluoroscopy, CT-guided administration offers superior anatomical resolution and planning flexibility—at the expense of ionizing radiation. Our results suggest that in complex anatomical cases, the benefits of CT outweigh the risks, particularly when dose-optimized protocols are in place. In straightforward cases or in younger patients, sonographic or fluoroscopic approaches may be preferable to minimize radiation burden, particularly in the context of long-term therapy requiring usually three annual injections, where cumulative exposure and adherence to the as low as reasonably achievable (ALARA) principle become clinically relevant [ 28 , 29 ]. Although median effective doses per procedure remained moderate (~ 2 mSv), consistent with values reported in previous studies, cumulative exposure may become clinically significant, especially in younger patients [ 30 ]. Therefore, dose optimization strategies should be integral to protocol design, such as minimizing scan length, using low-dose settings, and leveraging iterative reconstruction [ 21 ]. A key methodological strength of this study lies in the standardized documentation of procedural parameters and radiation exposure across a large number of procedures. Nevertheless, several limitations must be acknowledged. The retrospective design precludes causal inference and is susceptible to documentation bias. Additionally, the lack of a control group with other imaging techniques (e.g., sonographically or fluoroscopically guided punctures) limits the generalizability of findings [ 31 , 32 , 33 ]. Future prospective studies comparing CT guidance to alternative imaging modalities in anatomically challenging cohorts are warranted to further refine selection criteria and establish procedural algorithms. Conclusion CT-guided intrathecal administration of nusinersen is a safe, effective and well-established technique for treating patients with SMA, including those with complex spinal anatomy such as dorsal spondylodesis. The high technical success rate, low complication rate, and moderate radiation exposure support the clinical utility of this approach in routine practice. Individualized selection of puncture level and patient positioning, tailored to anatomical conditions, enables reliable implementation even in challenging cases. These findings highlight the importance of structured procedural planning and underscore the value of CT guidance as a robust imaging modality for long-term SMA therapy. Declarations Declarations Competing Interests T.H. has received advisory board and speaker honoraria from Biogen, Novartis, and Roche.C.K. has received advisory board and speaker honoraria from Biogen and Roche.All other authors declare no competing interests. Author Contribution Y.T. conceived and designed the study, performed data collection and statistical analysis, and drafted the manuscript.M.O., R.O.-S., L.K., D.R., M.D., D.B., J.H., C.K., T.H., M.F., C.D., and S.Z. contributed to data collection, interpretation, and critical revision of the manuscript.All authors reviewed and approved the final manuscript. Data Availability The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request. References Mercuri E, Bertini E, Iannaccone ST. Childhood spinal muscular atrophy: controversies and challenges. Lancet Neurol. 2012; 11(5):443–52. https://doi.org/10.1016/S1474-4422(12)70061-3 . Tisdale S, Pellizzoni L. Disease mechanisms and therapeutic approaches in spinal muscular atrophy. J Neurosci. 2015 10;35(23):8691 – 700. https://doi.org/10.1523/JNEUROSCI.0417-15.2015 . Keinath MC, Prior DE, Prior TW. Spinal Muscular Atrophy: Mutations, Testing, and Clinical Relevance. Appl Clin Genet. 2021;14:11–25. https://doi.org/10.2147/TACG.S239603 . Butchbach MER. Genomic variability in the survival motor neuron genes (SMN1 and SMN2): implications for spinal muscular atrophy phenotype and therapeutics development. Int J Mol Sci. 2021;22(15):7896. https://doi.org/10.3390/ijms22157896 . Lefebvre S, Burlet P, Liu Q, Bertrandy S, Clermont O, Munnich A, et al. Correlation between severity and SMN protein level in spinal muscular atrophy. Nat Genet. 1997;16(3):265–9. https://doi.org/10.1038/ng0797-265 . Feldkötter M, Schwarzer V, Wirth R, Wienker TF, Wirth B. Quantitative analyses of SMN1 and SMN2 based on real-time lightCycler PCR: fast and highly reliable carrier testing and prediction of severity of spinal muscular atrophy. Am J Hum Genet. 2002;70(2):358–68. https://doi.org/10.1086/338627 . Lefebvre S, Bürglen L, Reboullet S, Clermont O, Burlet P, Viollet L, et al. Identification and characterization of a spinal muscular atrophy-determining gene. Cell. 1995;80(1):155–65. https://doi.org/10.1016/0092-8674(95)90460-3 . Leckie J, Yokota T. Potential of Cell-Penetrating Peptide-Conjugated Antisense Oligonucleotides for the Treatment of SMA. Molecules. 2024;29(11):2658. https://doi.org/10.3390/molecules29112658 . Hoy SM. Nusinersen: A Review in 5q Spinal Muscular Atrophy. CNS Drugs. 2021;35(12):1317–28. https://doi.org/10.1007/s40263-021-00889-8 . Finkel RS, Chiriboga CA, Vajsar J, Day JW, Montes J, De Vivo DC, et al. Treatment of infantile-onset spinal muscular atrophy with nusinersen: a phase 2, open-label, dose-escalation study. Lancet. 2016;388(10063):3017–26. https://doi.org/10.1016/S0140-6736(16)31408-8 . Hagenacker T, Wurster CD, Günther R, Schreiber-Katz O, Osmanovic A, Petri S, Weiler M, et al. Nusinersen in adults with 5q spinal muscular atrophy: a non-interventional, multicentre, observational cohort study. Lancet Neurol. 2020;19(4):317–25. https://doi.org/10.1016/S1474-4422(20)30037-5 . Hagenacker T, Maggi L, Coratti G, Youn B, Raynaud S, Paradis AD, Mercuri E. Effectiveness of Nusinersen in Adolescents and Adults with Spinal Muscular Atrophy: Systematic Review and Meta-analysis. Neurol Ther. 2024;13(5):1483–1504. https://doi.org/10.1007/s40120-024-00653-2 . Stolte B, Totzeck A, Kizina K, Bolz S, Pietruck L, Mönninghoff C, et al. Feasibility and safety of intrathecal treatment with nusinersen in adult patients with spinal muscular atrophy. Ther Adv Neurol Disord. 2018;11:1756286418803246. https://doi.org/10.1177/1756286418803246 . Pechmann A, Langer T, Wider S, Kirschner J. Single-center experience with intrathecal administration of Nusinersen in children with spinal muscular atrophy type 1. Eur J Paediatr Neurol. 2018;22(1):122–27. https://doi.org/10.1016/j.ejpn.2017.11.001 . Wijngaarde CA, Brink RC, de Kort FAS, Stam M, Otto LAM, Asselman FL, et al. Natural course of scoliosis and lifetime risk of scoliosis surgery in spinal muscular atrophy. Neurology. 2019;93(2):e149-e58. https://doi.org/10.1212/WNL.0000000000007742 . Cordts I, Lingor P, Friedrich B, Pernpeintner V, Zimmer C, Deschauer M, Maegerlein C. Intrathecal nusinersen administration in adult spinal muscular atrophy patients with complex spinal anatomy. Ther Adv Neurol Disord. 2020;13:1756286419887616. https://doi.org/10.1177/1756286419887616 . Madan E, Carrié S, Donado C, Lobo K, Souris M, Laine R, et al. Nusinersen for Patients With Spinal Muscular Atrophy: 1415 Doses via an Interdisciplinary Institutional Approach. Pediatr Neurol. 2022;132:3340. https://doi.org/10.1016/j.pediatrneurol.2022.04.008 . International Commission on Radiological Protection. The 2007 recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP. (2007) 37, 1–332. https://doi.org/10.1016/j.icrp.2008.07.001 Wurster CD, Winter B, Wollinsky K, Ludolph AC, Uzelac Z, Witzel S, et al. Intrathecal administration of nusinersen in adolescent and adult SMA type 2 and 3 patients. J Neurol. 2019;266(1):183–94. https://doi.org/10.1007/s00415-018-9124-0 . Cordts I, Deschauer M, Lingor P, Burian E, Baum T, Zimmer C, et al. Radiation dose reduction for CT-guided intrathecal nusinersen administration in adult patients with spinal muscular atrophy. Sci Rep. 2020;10(1):3406. https://doi.org/10.1038/s41598-020-60240-x . Mousa MA, Aria DJ, Schaefer CM, Kaye RD, Abruzzo TA, Bernes SM, et al. A comprehensive institutional overview of intrathecal nusinersen injections for spinal muscular atrophy. Pediatr Radiol. 2018;48(12):1797–1805. https://doi.org/10.1007/s00247-018-4206-9 . Mendonça RH, Fernandes HDS, Pinto RBS, Matsui Júnior C, Polido GJ, Silva AMSD, et al. Managing intrathecal administration of nusinersen in adolescents and adults with 5q-spinal muscular atrophy and previous spinal surgery. Arq Neuropsiquiatr. 2021;79(2):127–32. https://doi.org/10.1590/0004-282X-ANP-2020-0200 . Kizina K, Stolte B, Totzeck A, Bolz S, Fleischer M, Mönninghoff C, et al. Clinical Implication of Dosimetry of Computed Tomography- and Fluoroscopy-Guided Intrathecal Therapy With Nusinersen in Adult Patients With Spinal Muscular Atrophy. Front Neurol. 2019;10:1166. https://doi.org/10.3389/fneur.2019.01166 . Spiliopoulos S, Reppas L, Zompola C, Palaiodimou L, Papadopoulou M, Filippiadis D, et al. Computed-tomography-guided transforaminal intrathecal nusinersen injection in adults with spinal muscular atrophy type 2 and severe spinal deformity. Feasibility, safety and radiation exposure considerations. Eur J Neurol. 2020;27(7):1343–49. https://doi.org/10.1111/ene.14245 . Weaver JJ, Hallam DK, Chick JFB, Vaidya S, Shin DS, Natarajan N, Rad N, et al. Transforaminal intrathecal delivery of nusinersen for older children and adults with spinal muscular atrophy and complex spinal anatomy: an analysis of 200 consecutive injections. J Neurointerv Surg. 2021;13(1):75–78. https://doi.org/10.1136/neurintsurg-2020-016058 . Towbin R, Schaefer C, Kaye R, Abruzzo T, Aria DJ. The Complex Spine in Children with Spinal Muscular Atrophy: The Transforaminal Approach-A Transformative Technique. AJNR Am J Neuroradiol. 2019;40(8):1422–26. https://doi.org/10.3174/ajnr.A6131 . Jochmann E, Steinbach R, Jochmann T, Chung HY, Rödiger A, Neumann R, et al. Experiences from treating seven adult 5q spinal muscular atrophy patients with Nusinersen. Ther Adv Neurol Disord. 2020;13:1756286420907803. https://doi.org/10.1177/1756286420907803 . Bevelacqua, J. J. Practical and effective ALARA. Health Phys. 98(Suppl 2), S39–47. Prasad, K. N., Cole, W. C. & Haase, G. M. Radiation protection in humans: extending the concept of as low as reasonably achievable (ALARA) from dose to biological damage. Br. J. Radiol. 77, 97–99. https://doi.org/10.1259/bjr/88081058 . Oldenburg D, Guberina N, Stolte B, Kizina K, Stenzel E, et al. Radiation exposure of image-guided intrathecal administration of nusinersen to adult patients with spinal muscular atrophy. Neuroradiology. 2019;61(5):565–74. https://doi.org/10.1007/s00234-019-02189-x . Veerapandiyan A, Pal R, D'Ambrosio S, Young I, Eichinger K, Collins E, Westesson PL, Kwon J, Ciafaloni E. Cervical puncture to deliver nusinersen in patients with spinal muscular atrophy. Neurology. 2018;91(7):e620-e24. https://doi.org/10.1212/WNL.0000000000006006 . Wei C, Liang Z, Wu Y, Liu S, Qiu J, Meng L, et al. Ultrasound-guided interlaminar approach for nusinersen administration in patients with spinal muscular atrophy with spinal fusion or severe scoliosis. Orphanet J Rare Dis. 2023;18(1):30. https://doi.org/10.1186/s13023-023-02630-8 . Ortiz CB, Kukreja KU, Lotze TE, Chau A. Ultrasound-guided cervical puncture for nusinersen administration in adolescents. Pediatr Radiol. 2019;49(1):136–40. https://doi.org/10.1007/s00247-018-4240-7 . Tables Table 1 Demographic and clinical characteristics of the study cohort. Characteristic Value Number of patients 44 Median Age (range) 31 years (14–58 years) Gender 23 male (52.3%), 21 female (47.7%) Dorsal spondylodesis present 21 patients (47.7%) Total number of interventions performed 458 SMA type - Type 1 3 patients (6.8%) - Type 2 28 patients (63.6%) - Type 3 13 patients (29.5%) Table 2 Comparison of procedural parameters between patients with and without dorsal spondylodesis. Parameters With dorsal spondylodesis Without dorsal spondylodesis p-value Number of procedures 208 (45.4%) 250 (54.6%) – Technically successful procedures 202 (97.1%) 247 (98.8%) 0.311 Puncture duration (median, range) 11.9 min (2.8–96.6) 10.3 min (1.6–76.0) 0.0031 Procedure duration (median, range) 16.3 min (7.4–102.9) 14.0 min (5.1–134.1) 0.0028 Table 3 Overview of periprocedural complications. Type of complication n Proportion of all interventions (%) Pain 3 0.7% Needle tract hematoma 1 0.2% Retroperitoneal hematoma 1 0.2% All complications 5 1.1% Table 4 Comparison of key intervention parameters for all procedures, procedures with complications and technically unsuccessful procedures. Parameters All interventions (n = 458) Interventions with complications (n = 5) Unsuccessful interventions (n = 9) Median number of repositioning attempts (IQR, range) 0 (0–0, 0–5) 1 (1–2, 0–4) 1 (0–2, 0–5) Median puncture duration (IQR, range) 11.1 min (7.7–16.2, 1.6–96.6) 55.8 min (55.1–76, 20.9–95.7) 52.2 min (33.4–65.8, 18.4–96.6) Median procedure duration (IQR, range) 14.8 min (10.9–20.8, 5.1-134.1) 59.7 min (59.1–81.9, 41.7-102.9) 58.4 min (45.9–69.7, 22.2-102.9) Dorsal spondylodesis (%) 202 (44,1%) 4 (80.0%) 6 (66,7%) Table 5 Technical success rates by patient positioning. Patient positioning Number of procedures Number of successful procedures Success rate (%) Prone position 44 (9.6%) 43 97.7% Left lateral position 233 (50.9%) 228 97.9% Right lateral position 165 (36.0%) 162 98.2% Right lateral/prone position 15 (3.3%) 15 100% Left lateral/prone position 1 (0.2%) 1 100% Table 6 Radiation exposure. Parameters Total procedures Procedures with dorsal spondylodesis Procedures without dorsal spondylodesis Unsuccessful procedures Interventions with complications CTDIvol (median, IQR) 8.67 (5.76–13.62) 9.68 (7.53–13.92) 7.24 (4.12–12.64) 17.80 (8.58–30.87) 9.78 (5.08–22.50) DLP (median, IQR) 120.99 (74.73-218.36) 141.75 (94.81-239.92) 104.66 (58.66-191.14) 414.38 (119.27–598.70) 414.38 (211.65-446.61) Effective dose (median, IQR) 2.02 (1.35–3.17) 2.22 (1.60–3.25) 1.74 (1.08–3.04) 4.25 (2.54–7.69) 3.82 (3.45–4.25) CTDI: Computed Tomography Dose Index; DLP = Dose-Length Product Additional Declarations Competing interest reported. T.H. has received advisory board and speaker honoraria from Biogen, Novartis, and Roche. C.K. has received advisory board and speaker honoraria from Biogen and Roche. All other authors declare no competing interests. Cite Share Download PDF Status: Published Journal Publication published 25 Nov, 2025 Read the published version in Clinical Neuroradiology → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7722326","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":528326427,"identity":"8f406773-4d16-481e-81f6-6bc0bffcebc3","order_by":0,"name":"Yannick Laurent Thal","email":"data:image/png;base64,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","orcid":"","institution":"Essen University Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yannick","middleName":"Laurent","lastName":"Thal","suffix":""},{"id":528326428,"identity":"5ba8c28f-596c-4c1c-b0b8-b50070f2a896","order_by":1,"name":"Marcel Optiz","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Marcel","middleName":"","lastName":"Optiz","suffix":""},{"id":528326429,"identity":"e8a95da9-9b22-4ec0-853f-8ba791b5be25","order_by":2,"name":"Raya Serger","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Raya","middleName":"","lastName":"Serger","suffix":""},{"id":528326430,"identity":"b5cec3f2-cf4d-4c08-bb94-25df90f1f017","order_by":3,"name":"Laura Kluener","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Laura","middleName":"","lastName":"Kluener","suffix":""},{"id":528326431,"identity":"f3d5670c-663f-4cd3-b268-128fcc89ab68","order_by":4,"name":"Daniel Rosok","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Daniel","middleName":"","lastName":"Rosok","suffix":""},{"id":528326432,"identity":"f7a0e839-f574-4343-b3fa-b9d854e95cbc","order_by":5,"name":"Marcel Alexander Drews","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Marcel","middleName":"Alexander","lastName":"Drews","suffix":""},{"id":528326433,"identity":"190d3730-d5df-4fec-9823-8c81e16d07cd","order_by":6,"name":"Denise Bos","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Denise","middleName":"","lastName":"Bos","suffix":""},{"id":528326434,"identity":"53257c98-7a4a-48cf-8011-67127b0dc5eb","order_by":7,"name":"Johannes Haubold","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Johannes","middleName":"","lastName":"Haubold","suffix":""},{"id":528326435,"identity":"31a8c107-7789-466a-b78c-7a95e8cf4fa0","order_by":8,"name":"Christoph Kleinschnitz","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Christoph","middleName":"","lastName":"Kleinschnitz","suffix":""},{"id":528326436,"identity":"5284c1ac-1e5e-4d33-9bd7-c5d127ed57ac","order_by":9,"name":"Tim Hagenacker","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tim","middleName":"","lastName":"Hagenacker","suffix":""},{"id":528326437,"identity":"7c244917-bdd7-4e8b-a86c-cbfd12143706","order_by":10,"name":"Michael Forsting","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Michael","middleName":"","lastName":"Forsting","suffix":""},{"id":528326438,"identity":"a6523ac5-d39d-40e2-9ef8-7cb0f5f67666","order_by":11,"name":"Cornelius Deuschl","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Cornelius","middleName":"","lastName":"Deuschl","suffix":""},{"id":528326439,"identity":"cecda51a-f086-48d5-be21-00902e5f67f2","order_by":12,"name":"Zensen Sebastian","email":"","orcid":"","institution":"Essen University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zensen","middleName":"","lastName":"Sebastian","suffix":""}],"badges":[],"createdAt":"2025-09-26 13:38:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7722326/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7722326/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00062-025-01590-9","type":"published","date":"2025-11-25T15:57:40+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":93732316,"identity":"2be83f4c-0be7-4122-a52e-fa7597e8c952","added_by":"auto","created_at":"2025-10-17 02:30:04","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2623863,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptAnonymized.docx","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/e96cda89151a889524d185fa.docx"},{"id":93730838,"identity":"61383008-491f-4734-9c8e-66ca23602ce6","added_by":"auto","created_at":"2025-10-17 02:22:04","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":13338,"visible":true,"origin":"","legend":"","description":"","filename":"cf1b3734c90548aaa716181a4ca08e5f.json","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/639bf87a8c104ba23e0883c5.json"},{"id":93730843,"identity":"e2d02bcf-e9b1-4d25-9508-8f07176d7512","added_by":"auto","created_at":"2025-10-17 02:22:04","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":106895,"visible":true,"origin":"","legend":"","description":"","filename":"cf1b3734c90548aaa716181a4ca08e5f1enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/a8062a7b20bd0a0a68906f5a.xml"},{"id":93730861,"identity":"4a6adb6d-81c7-4132-8713-25c4bbd40eb2","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":105642,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/a70528787a557c5bf4e703e8.png"},{"id":93730853,"identity":"9fd1d9fd-3b00-40da-8a19-e3c23c2d29a2","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"emf","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":3553944,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.emf","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/9f3ac8bac4eb04571b2c9206.emf"},{"id":93730850,"identity":"a1e5ae08-88f0-4dc8-94ce-e6693b56ab38","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":193934,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/245d2569493c6b33dc1e03c0.png"},{"id":93730855,"identity":"8698e76b-4554-42a2-963e-2cd1138aef7a","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":152833,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/c9d1988638072ba7ced4312d.png"},{"id":93730859,"identity":"debab8b0-61de-48dc-8c8b-5dda05581690","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":158382,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/585f98574389e310143026bd.png"},{"id":93732317,"identity":"9436fd6f-6b23-44d2-b994-567806913af5","added_by":"auto","created_at":"2025-10-17 02:30:04","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":20315,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/3130f0458a869f45b72e7ed3.png"},{"id":93732319,"identity":"cd35de45-34c7-4357-91c5-abba8d90ac38","added_by":"auto","created_at":"2025-10-17 02:30:05","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":92504,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/b5cd0b913a6b409d874fcecb.png"},{"id":93730864,"identity":"07342075-ba9f-42d8-82ab-081a5393459f","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":26118,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/1e5873ad8663a9fa83eaac71.png"},{"id":93730862,"identity":"13f23591-63d8-49bd-9d7e-b534bceadf2c","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":17018,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/3d92b6b464f63a08e72a262b.png"},{"id":93730868,"identity":"445ec27e-991b-4563-9f04-d8a24c19108e","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":18494,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/3e50a0c5e68a44101aecfcc7.png"},{"id":93730872,"identity":"54d2973d-c204-4716-86ef-a4b99e15e5c2","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"xml","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":103588,"visible":true,"origin":"","legend":"","description":"","filename":"cf1b3734c90548aaa716181a4ca08e5f1structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/f075bfd3933d8a19156cee4b.xml"},{"id":93730865,"identity":"39e04f85-ed73-4973-8b43-4bbd82dd68e0","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"html","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":112917,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/06dfe013c557c9d5bfdeeb9e.html"},{"id":93730840,"identity":"c7096700-95c8-42b8-9921-5a1a126bd331","added_by":"auto","created_at":"2025-10-17 02:22:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":86123,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of study cohort selection.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/c9028b1cda85805fee8ac8b3.png"},{"id":93730842,"identity":"21b09884-ab9b-4acb-bf84-e9070906323c","added_by":"auto","created_at":"2025-10-17 02:22:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":634693,"visible":true,"origin":"","legend":"\u003cp\u003eRepresentative CT planning images in patients with and without dorsal spinal fusion. Scout image (a) and corresponding axial CT image (b) in a patient without spinal instrumentation, showing unobstructed anatomical landmarks and a straightforward intrathecal needle path. Scout image (c) and axial CT image (d) in a patient with dorsal spondylodesis, showing increased procedural complexity due to altered bony anatomy and spinal hardware, necessitating advanced planning and angulated needle trajectory.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/348dcb5879d82669384976e8.png"},{"id":93730858,"identity":"090f28a2-3a21-4280-9ad0-ab9c2be990fe","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":104785,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of the number of repositionings, stratified by presence of dorsal spondylodesis, procedural success, and occurrence of complications.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/9a9470c014b9041079b801b6.png"},{"id":93730863,"identity":"4c1f446d-30ab-45ba-8500-41cb40154bba","added_by":"auto","created_at":"2025-10-17 02:22:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":113794,"visible":true,"origin":"","legend":"\u003cp\u003eDuration of procedure and puncture by technical outcome and complication status. A small number of outliers were excluded from the graph to improve visualization; however, all data points were included in the statistical calculations. **** = p \u0026lt; 0.0001.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/b44c743e6bbfc9274e9d0ab6.png"},{"id":93732320,"identity":"4f7e86a3-3ac8-481c-90cc-1181d55a3f7a","added_by":"auto","created_at":"2025-10-17 02:30:05","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":120712,"visible":true,"origin":"","legend":"\u003cp\u003eRadiation exposure parameters in patients with and without dorsal spinal fusion. A small number of outliers were excluded from the graphs to improve visualization; however, all data points were included in the statistical calculations. **** = p \u0026lt; 0.0001.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/ef4b2a2b448f598736cd8b08.png"},{"id":97178419,"identity":"55f8d367-0db9-48ae-abb5-f47a01d3e85a","added_by":"auto","created_at":"2025-12-01 16:09:45","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1921691,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7722326/v1/8854ccdb-eeec-4ad1-945f-8d97978f9ab3.pdf"}],"financialInterests":"Competing interest reported. T.H. has received advisory board and speaker honoraria from Biogen, Novartis, and Roche.\nC.K. has received advisory board and speaker honoraria from Biogen and Roche.\nAll other authors declare no competing interests.","formattedTitle":"CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSpinal muscular atrophy (SMA) is a rare autosomal recessive motor neuron disease characterized by progressive degeneration of motor neurons in the anterior horn of the spinal cord [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Clinically, it manifests with generalized muscle hypotonia and atrophy, which can present from early infancy to adulthood, depending on the disease subtype [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The underlying cause is a mutation in the \u003cem\u003eSMN1\u003c/em\u003e gene, while disease severity correlates with the number of \u003cem\u003eSMN2\u003c/em\u003e gene copies [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eWith the approval of nusinersen in 2017, the first disease-modifying therapy became available. It enhances the alternative splicing of \u003cem\u003eSMN2\u003c/em\u003e transcripts, thereby increasing production of functional SMN protein [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. The clinical benefits of nusinersen have been well demonstrated in both pediatric and adult populations, leading to widespread adoption as a standard of care [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. This is further supported by a recent systematic review and meta-analysis in adolescents and adults, which confirmed that nusinersen treatment leads to stabilization or improvement of motor function across a broad spectrum of SMA patients [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. However, its mode of administration\u0026mdash;repeated intrathecal injection\u0026mdash;poses considerable logistical and technical challenges, particularly in patients with severe scoliosis, complex spinal anatomy, or prior spinal instrumentation [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eImage guidance such as fluoroscopy or ultrasound has been explored, but often prove insufficient in complex cases or in centers lacking specific expertise [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. CT-guided lumbar puncture, by contrast, provides high-resolution anatomical visualization and has emerged as a safe and effective technique for intrathecal drug administration in complex cases [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Prior case series and institutional experiences have demonstrated feasibility and safety; however, large-scale data on long-term implementation, technical success rates, and cumulative radiation exposure are still limited, especially in adult and surgically pretreated populations [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe aim of this study was to analyze the technical feasibility, safety profile, and radiation exposure of CT-guided intrathecal nusinersen administration in a large cohort of patients with SMA. In addition, the impact of anatomical factors\u0026mdash;in particular dorsal spondylodesis\u0026mdash;as well as patient positioning and puncture level were assessed.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStudy Design and Cohort\u003c/h2\u003e\u003cp\u003e This retrospective, single-center observational study was approved by the local ethics committee and the requirement for informed consent was waived. All CT-guided procedures performed between October 2017 and August 2024 were reviewed. The study cohort selection process is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. All procedures unrelated to nusinersen injections or in patients lacking a confirmed diagnosis of SMA were excluded.\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eProcedural Technique\u003c/h3\u003e\n\u003cp\u003eAll nusinersen injections were performed under CT guidance using one of the following scanners: SOMATOM Definition AS+, SOMATOM Definition Flash, SOMATOM X.ceed, or NAEOTOM Alpha. CT scans were acquired in a step-and-shot technique. For image guidance, a single axial sequence was reconstructed in three slices with 3-mm thickness, using comparable technical parameters across all scanners. The median tube voltage was 115 kV (IQR 110\u0026ndash;120) and the median tube current time product was 87 mAs (IQR 69\u0026ndash;128). All procedures were preceded by thorough preparation, including pre-procedural planning, imaging, laboratory testing, and written informed consent. Patient positioning was adapted to individual anatomical and clinical considerations, with punctures typically performed in the lateral or prone position. The puncture level was selected based on anatomical feasibility and any prior surgical interventions (e.g., spondylodesis, sclerotic changes, osteophytes). All punctures were performed by board-certified neuroradiologists under standardized conditions. A consistent protocol regarding antiseptic preparation and needle type was followed throughout to ensure procedural uniformity and minimize variability. Nusinersen administration was carried out by the treating neurologists. Procedural documentation, including time stamps (start, end, needle insertion), was recorded in the RIS (Radiology Information System) and PACS (Picture Archiving and Communication System). Technical success was defined as successful intrathecal needle placement with complete administration of nusinersen. Complications were systematically recorded both during the procedure and throughout the postprocedural hospital stay until discharge. All adverse events were evaluated based on clinical documentation and imaging findings.\u003c/p\u003e\n\u003ch3\u003eData Collection and Evaluation\u003c/h3\u003e\n\u003cp\u003eThe following parameters were recorded: demographic data, SMA subtype, patient positioning, puncture level, presence of dorsal spondylodesis, technical success, number of repositioning attempts, complications during the procedure and until discharge. The total intervention time was defined as the duration from acquisition of the planning scan to the documented end of the procedure. Puncture duration was defined as the time between the first attempt at needle placement and successful intrathecal nusinersen injection. 9 cases were excluded from time-based analysis, due to incomplete documentation or procedure abortion.\u003c/p\u003e\n\u003ch3\u003eRadiation Exposure Assessment\u003c/h3\u003e\n\u003cp\u003eRadiation exposure was documented for each procedure using the parameters CTDIvol (volumetric computed tomography dose index) in mGy, dose-length product (DLP) in mGy\u0026middot;cm, and effective dose in mSv. The effective dose for CT-guided injections was calculated according to ICRP (International Commission on Radiological Protection) Publication 103 [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In 11 procedures, radiation dose data were incomplete or missing and were therefore excluded from at least one dose-related analysis.\u003c/p\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eStatistical analysis was performed using GraphPad Prism (version 10.5.0; GraphPad Software, San Diego, CA, USA). Categorical variables (e.g., technical success, complications) were analyzed using Fisher\u0026rsquo;s exact test or Chi-squared test, as appropriate. Continuous variables were non-normally distributed and are expressed as medians with interquartile ranges (IQR). Two-group comparisons (e.g., spondylodesis vs. no spondylodesis, successful vs. failed procedures) were carried out using the Mann\u0026ndash;Whitney U test. Comparisons across more than two groups (e.g., puncture level, patient positioning) were assessed with the Kruskal\u0026ndash;Wallis test followed, where significant, by Dunn\u0026rsquo;s multiple comparisons post-hoc analysis. Correlations between number of needle repositioning attempts, procedural durations, and radiation dose parameters were evaluated using Spearman\u0026rsquo;s rank correlation. Statistical significance was defined as p\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eOut of 1,074 CT-guided spinal interventions, 616 procedures in 517 patients were excluded because they were either unrelated to nusinersen injections or lacked a confirmed diagnosis of SMA (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The study cohort comprised 458 CT-guided procedures in 44 patients with confirmed SMA. The median age was 31 years (IQR 25\u0026ndash;44 years, range 14\u0026ndash;58 years). 21 (47.7%) of patients were female. SMA subtype distribution included type 1 in 6.8% (3/44), type 2 in 63.6% (28/44) and type 3 in 29.5% (13/44). Dorsal spondylodesis was present in 47.7% (21/44). A summary of demographic and clinical characteristics is presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003ch3\u003eTechnical Success\u003c/h3\u003e\n\u003cp\u003e449 out of 458 procedures were technically successful, corresponding to an overall technical success rate of 98.3%. Among patients with dorsal spondylodesis, the technical success rate was 97.1% (202/208), compared to 98.8% (247/250) in patients without dorsal spondylodesis (p\u0026thinsp;=\u0026thinsp;0.311). A detailed comparison of technical success rates and procedure times is shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Notably, 66% (6/9) failed procedures occurred in patients with dorsal spondylodesis. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e illustrates the increased technical complexity of CT-guided intrathecal nusinersen administration in patients with dorsal spondylodesis compared to those without spinal instrumentation.\u003c/p\u003e\n\u003ch3\u003eComplications\u003c/h3\u003e\n\u003cp\u003ePeriprocedural complications occurred in 1.1% (5/458) and included 3 cases of postprocedural pain, 1 needle tract hematoma, and 1 retroperitoneal hematoma (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). All complications were transient and without long-term sequelae. Complications occurred more frequently in patients with dorsal spondylodesis (4/203; 1.97%) compared to those without (1/255; 0.39%), although this difference did not reach statistical significance (p\u0026thinsp;=\u0026thinsp;0.176). Procedures with complications or technical failure were associated with significantly prolonged procedure and puncture durations (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003eNeedle Repositioning\u003c/h2\u003e\u003cp\u003eThe median number of repositioning attempts across all 458 procedures was 0 (range 0\u0026ndash;5), indicating that most procedures were performed without needle repositioning. Although the median number of repositioning attempts was 0 in both groups, procedures in patients with dorsal spondylodesis required repositioning more frequently overall, resulting in a statistically significant difference compared to those without spondylodesis (p\u0026thinsp;=\u0026thinsp;0.012). Furthermore, the five procedures with complications required significantly more repositioning attempts (median 1, range 0\u0026ndash;4) than those without (median 0; p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). In the nine technically unsuccessful procedures, the median number of repositioning attempts was 1 (range 0\u0026ndash;5), which was significantly higher compared to successful procedures (median 0; p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). These findings suggest that increased procedural complexity\u0026mdash;due to anatomical challenges or difficult access\u0026mdash;was associated with a higher need for repositioning attempts. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the distribution of the number of repositionings, stratified by presence of spinal fusion, procedural success, and occurrence of complications. The number of needle repositioning attempts correlated significantly with puncture duration (Spearman r\u0026thinsp;=\u0026thinsp;0.34, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), procedure duration (r\u0026thinsp;=\u0026thinsp;0.34, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), and radiation exposure parameters including CTDIvol (r\u0026thinsp;=\u0026thinsp;0.16, p\u0026thinsp;=\u0026thinsp;0.0008), DLP (r\u0026thinsp;=\u0026thinsp;0.21, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), and effective dose (r\u0026thinsp;=\u0026thinsp;0.23, p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), indicating increased complexity and resource utilization in procedures requiring multiple needle adjustments.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003ePatient Positioning\u003c/h2\u003e\u003cp\u003eIn the prone position, 97.7% (43/44) of procedures were successful. In the left lateral position 97.9% (228/233) and in the right lateral position 98.2% (162/165) were successful. In addition, the technical success rate was 100% (5/5) in interventions in a combined right lateral/prone position and 100% (1/1) in a left lateral/prone position. Detailed results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. Patient positioning (prone, left lateral, right lateral, or combined) had no significant effect on technical success rates (p\u0026thinsp;\u0026gt;\u0026thinsp;0.999). While patient positioning had no significant effect on technical success, it was significantly associated with puncture duration (p\u0026thinsp;=\u0026thinsp;0.005). Median puncture times were 10.8 min (IQR 7.7\u0026ndash;15.1) in right lateral, 7.3 min (IQR 6.2\u0026ndash;8.8) in combined positions, 11.2 min (IQR 7.5\u0026ndash;16.9) in left lateral, and 11.9 min (IQR 10.2\u0026ndash;23.9) in prone position, with post-hoc analysis showing a significantly shorter duration in combined vs. prone positioning (p\u0026thinsp;=\u0026thinsp;0.0044). Radiation dose parameters varied significantly by patient positioning. Median CTDIvol was highest in the prone position (11.52 mGy), followed by right lateral (8.97 mGy), left lateral (8.35 mGy), and lowest in the combined position (4.17 mGy; p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). DLP showed a similar pattern, with medians of 168.9 mGy\u0026middot;cm (prone), 112.5 mGy\u0026middot;cm (right lateral), 127.9 mGy\u0026middot;cm (left lateral), and 51.4 mGy\u0026middot;cm (p\u0026thinsp;=\u0026thinsp;0.0001). Effective dose was also highest in prone position (2.45 mSv) and lowest in combined position (1.17 mSv; p\u0026thinsp;=\u0026thinsp;0.0143). Post-hoc analysis revealed that the combined position consistently yielded significantly lower radiation doses compared to other positions, whereas no significant differences were found between prone, left lateral, and right lateral positions. Patient positioning (prone, left lateral, right lateral, or combined) had no significant effect on the number of needle repositioning attempts (Kruskal\u0026ndash;Wallis p\u0026thinsp;=\u0026thinsp;0.178; Dunn\u0026rsquo;s multiple comparisons: all adjusted p\u0026thinsp;\u0026gt;\u0026thinsp;0.23).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003ePuncture Levels\u003c/h2\u003e\u003cp\u003ePuncture level selection was based on individual anatomy and any pre-existing surgical conditions, such as dorsal spondylodesis. A total of 458 puncture attempts were performed. The most frequently chosen puncture levels were L5/S1 (49.1%, 225/225; technical success rate: 100%), L4/5 (38.6%, 175/177; 98.9%), and L3/4 (3.3%, 14/15; 93.3%). Pairwise comparison revealed a significantly higher technical success rate for L5/S1 compared to L3/4 (p\u0026thinsp;=\u0026thinsp;0.024), whereas no significant differences were observed between L5/S1 and L4/5 (p\u0026thinsp;=\u0026thinsp;0.234) or between L4/5 and L3/4 (p\u0026thinsp;=\u0026thinsp;0.265). Puncture duration did not differ significantly between the puncture levels L5/S1, L4/5, and L3/4 (Kruskal\u0026ndash;Wallis test, p\u0026thinsp;=\u0026thinsp;0.705; all post-hoc comparisons non-significant).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003eProcedure and Puncture Duration\u003c/h2\u003e\u003cp\u003eThe median puncture duration for all procedures was 11.1 minutes (IQR 7.7\u0026ndash;16.2 minutes, range 1.6\u0026ndash;96.6 minutes), and the median total procedure duration was 14.8 minutes (IQR 10.9\u0026ndash;20.8 minutes, range 5.1\u0026ndash;134.1 minutes). In patients with dorsal spondylodesis, median puncture duration was 11.9 minutes (IQR 9.1\u0026ndash;17.6 minutes, range: 2.8\u0026ndash;96.6 minutes) and the procedure duration was 16.3 minutes (IQR 12.5\u0026ndash;22.1 minutes, range: 7.4\u0026ndash;102.9 minutes). In patients without dorsal spondylodesis, these durations were 10.3 minutes (IQR 7.2\u0026ndash;15.3, range: 1.6\u0026ndash;76.0 minutes) and 14.0 minutes (IQR 10.4\u0026ndash;20.6, range: 5.1\u0026ndash;134.1 minutes), respectively. These differences were statistically significant (puncture duration: p\u0026thinsp;=\u0026thinsp;0.0031; procedure duration: p\u0026thinsp;=\u0026thinsp;0.0028), indicating greater procedural complexity in the spinal fusion group. In interventions with complications, the puncture duration was 55.8 minutes (IQR 55.1\u0026ndash;76, range: 20.9\u0026ndash;95.7 minutes) and the procedure duration was 59.7 minutes (IQR 59.1\u0026ndash;81.9, range: 41.7\u0026ndash;102.9 minutes). These differences were statistically significant for both puncture and procedure duration (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). In 8 of the 9 technically unsuccessful procedures with complete documentation, the median puncture duration was 52.2 min (IQR: 33.4\u0026ndash;65.8; range: 18.4\u0026ndash;96.6), and the total procedure duration was 58.4 min (IQR: 45.9\u0026ndash;69.7; range: 22.2\u0026ndash;102.9), both significantly longer than in successful interventions (puncture: 11.1 min; procedure: 14.8 min; p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). Figure\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e illustrates the duration of procedure and puncture by technical outcome and complication status.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\u003ch2\u003eRadiation Exposure\u003c/h2\u003e\u003cp\u003eThe median CTDIvol of the 447 analyzed procedures was 8.67 mGy (IQR: 5.76\u0026ndash;13.62), the median DLP was 121 mGy\u0026middot;cm (IQR: 75\u0026ndash;218), and the median effective dose was 2.02 mSv (IQR: 1.35\u0026ndash;3.17). In patients with dorsal spondylodesis, the CTDIvol was 9.68 mGy (IQR: 7.53\u0026ndash;13.92), the DLP was 142 mGy\u0026middot;cm (IQR: 95\u0026ndash;240) and the effective dose was 2.22 mSv (IQR: 1.60\u0026ndash;3.25). In patients without dorsal spondylodesis, lower values were recorded: CTDIvol 7.24 mGy (IQR: 4.12\u0026ndash;12.64), DLP 105 mGy\u0026middot;cm (IQR: 59\u0026ndash;191) and effective dose 1.74 mSv (IQR: 1.08\u0026ndash;3.04). All three radiation dose parameters were significantly higher in patients with dorsal spondylodesis: CTDIvol (median 9.68 mGy vs. 7.24 mGy), DLP (142 vs. 105 mGy\u0026middot;cm), and effective dose (2.22 vs. 1.74 mSv; all p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001, Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). These differences underline the increased technical demands and prolonged scan durations in this patient subgroup. In procedures with complications, radiation exposure was higher: CTDIvol 9.78 mGy (IQR: 5.08\u0026ndash;22.50), DLP 414 mGy\u0026middot;cm (IQR: 212\u0026ndash;447) and effective dose 3.82 mSv (IQR: 3.45\u0026ndash;4.25). Although CTDIvol did not differ significantly between procedures with and without complications (median 9.78 mGy vs. 8.67 mGy; p\u0026thinsp;=\u0026thinsp;0.608), both DLP (414.4 vs. 121.0 mGy\u0026middot;cm; p\u0026thinsp;=\u0026thinsp;0.040) and effective dose (3.82 vs. 2.01 mSv; p\u0026thinsp;=\u0026thinsp;0.030) were significantly higher in procedures with complications, likely reflecting the need for additional scan acquisitions in technically demanding cases. In unsuccessful procedures, radiation exposure was highest: CTDIvol 17.8 mGy (IQR: 8.58\u0026ndash;30.87), DLP 414 mGy\u0026middot;cm (IQR: 119\u0026ndash;599), and effective dose 4.25 mSv (IQR: 2.54\u0026ndash;7.69); all values were significantly higher compared to successful procedures (CTDIvol 17.8 mGy vs. 8.7 mGy, p\u0026thinsp;=\u0026thinsp;0.047; DLP 414 mGy\u0026middot;cm vs. 121 mGy\u0026middot;cm, p\u0026thinsp;=\u0026thinsp;0.014; effective dose 4.25 mSv vs. 2.02 mSv, p\u0026thinsp;=\u0026thinsp;0.002). A summary of radiation exposure parameters across patient subgroups is provided in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e.\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study provides a comprehensive evaluation of CT-guided intrathecal nusinersen administration in adolescent and adult patients with SMA in a routine clinical setting. With a high technical success rate of 98.3%, it confirms the feasibility and reliability of CT-guided lumbar puncture\u0026mdash;even under complex anatomical conditions such as dorsal spinal fusion [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe observed differences in technical success, duration, and radiation exposure between patients with and without spinal instrumentation reflect the increased technical demands in surgically altered anatomy, which was also evident in the higher repositioning rates observed in this subgroup [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. These findings are consistent with previous reports [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], which also demonstrated higher effective doses in patients with dorsal spondylodesis compared to those without. Our study extends these observations by confirming them in a substantially larger cohort and by providing a more detailed analysis of procedural duration and technical outcomes. Although patients with dorsal spondylodesis demonstrated a slightly lower technical success rate and significantly longer procedure and puncture durations, the outcomes remained favorable overall. Nonetheless, the technical success rate of over 97% in the fusion subgroup underlines the robustness of the CT-guided approach. These findings highlight that even challenging cases can be managed safely and effectively with proper planning and technique [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eImportantly, procedures associated with complications or technical failure showed significantly prolonged durations and markedly increased radiation exposure. These findings underscore the importance of minimizing procedure complexity through individualized preparation and image-based planning, particularly in patients with altered spinal anatomy or previous surgical interventions [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe low overall complication rate of 1.1%, with no long-term sequelae, further supports the safety of this method and is consistent with previously published data [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The predominance of complications in the fusion group is noteworthy and may serve as a reminder for heightened procedural awareness in this subgroup. Importantly, both failed and complicated procedures were associated with longer durations and markedly increased radiation doses\u0026mdash;underscoring the importance of careful planning, patient-specific protocol optimization, and dose-saving strategies.\u003c/p\u003e\u003cp\u003ePatient positioning did not appear to have a substantial impact on technical success rates. This suggests that procedural positioning can be tailored flexibly based on anatomical and clinical considerations, without compromising safety or effectiveness.\u003c/p\u003e\u003cp\u003eThe puncture level L5/S1 proved to be the most accessible and reliable, achieving a 100% success rate. In contrast, alternative or repeated punctures at other levels were more commonly associated with technical failure, particularly in the presence of prior instrumentation.\u003c/p\u003e\u003cp\u003eCompared to alternative imaging modalities such as ultrasound or fluoroscopy, CT-guided administration offers superior anatomical resolution and planning flexibility\u0026mdash;at the expense of ionizing radiation. Our results suggest that in complex anatomical cases, the benefits of CT outweigh the risks, particularly when dose-optimized protocols are in place. In straightforward cases or in younger patients, sonographic or fluoroscopic approaches may be preferable to minimize radiation burden, particularly in the context of long-term therapy requiring usually three annual injections, where cumulative exposure and adherence to the as low as reasonably achievable (ALARA) principle become clinically relevant [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Although median effective doses per procedure remained moderate (~\u0026thinsp;2 mSv), consistent with values reported in previous studies, cumulative exposure may become clinically significant, especially in younger patients [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. Therefore, dose optimization strategies should be integral to protocol design, such as minimizing scan length, using low-dose settings, and leveraging iterative reconstruction [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA key methodological strength of this study lies in the standardized documentation of procedural parameters and radiation exposure across a large number of procedures. Nevertheless, several limitations must be acknowledged. The retrospective design precludes causal inference and is susceptible to documentation bias. Additionally, the lack of a control group with other imaging techniques (e.g., sonographically or fluoroscopically guided punctures) limits the generalizability of findings [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Future prospective studies comparing CT guidance to alternative imaging modalities in anatomically challenging cohorts are warranted to further refine selection criteria and establish procedural algorithms.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCT-guided intrathecal administration of nusinersen is a safe, effective and well-established technique for treating patients with SMA, including those with complex spinal anatomy such as dorsal spondylodesis. The high technical success rate, low complication rate, and moderate radiation exposure support the clinical utility of this approach in routine practice. Individualized selection of puncture level and patient positioning, tailored to anatomical conditions, enables reliable implementation even in challenging cases. These findings highlight the importance of structured procedural planning and underscore the value of CT guidance as a robust imaging modality for long-term SMA therapy.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eDeclarations\u003c/h2\u003e\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003cp\u003eT.H. has received advisory board and speaker honoraria from Biogen, Novartis, and Roche.C.K. has received advisory board and speaker honoraria from Biogen and Roche.All other authors declare no competing interests.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eY.T. conceived and designed the study, performed data collection and statistical analysis, and drafted the manuscript.M.O., R.O.-S., L.K., D.R., M.D., D.B., J.H., C.K., T.H., M.F., C.D., and S.Z. contributed to data collection, interpretation, and critical revision of the manuscript.All authors reviewed and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMercuri E, Bertini E, Iannaccone ST. Childhood spinal muscular atrophy: controversies and challenges. Lancet Neurol. 2012; 11(5):443\u0026ndash;52. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S1474-4422(12)70061-3\u003c/span\u003e\u003cspan address=\"10.1016/S1474-4422(12)70061-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTisdale S, Pellizzoni L. Disease mechanisms and therapeutic approaches in spinal muscular atrophy. J Neurosci. 2015 10;35(23):8691\u0026thinsp;\u0026ndash;\u0026thinsp;700. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1523/JNEUROSCI.0417-15.2015\u003c/span\u003e\u003cspan address=\"10.1523/JNEUROSCI.0417-15.2015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKeinath MC, Prior DE, Prior TW. Spinal Muscular Atrophy: Mutations, Testing, and Clinical Relevance. Appl Clin Genet. 2021;14:11\u0026ndash;25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2147/TACG.S239603\u003c/span\u003e\u003cspan address=\"10.2147/TACG.S239603\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eButchbach MER. Genomic variability in the survival motor neuron genes (SMN1 and SMN2): implications for spinal muscular atrophy phenotype and therapeutics development. Int J Mol Sci. 2021;22(15):7896. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/ijms22157896\u003c/span\u003e\u003cspan address=\"10.3390/ijms22157896\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLefebvre S, Burlet P, Liu Q, Bertrandy S, Clermont O, Munnich A, et al. Correlation between severity and SMN protein level in spinal muscular atrophy. Nat Genet. 1997;16(3):265\u0026ndash;9. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/ng0797-265\u003c/span\u003e\u003cspan address=\"10.1038/ng0797-265\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFeldk\u0026ouml;tter M, Schwarzer V, Wirth R, Wienker TF, Wirth B. Quantitative analyses of SMN1 and SMN2 based on real-time lightCycler PCR: fast and highly reliable carrier testing and prediction of severity of spinal muscular atrophy. Am J Hum Genet. 2002;70(2):358\u0026ndash;68. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1086/338627\u003c/span\u003e\u003cspan address=\"10.1086/338627\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLefebvre S, B\u0026uuml;rglen L, Reboullet S, Clermont O, Burlet P, Viollet L, et al. Identification and characterization of a spinal muscular atrophy-determining gene. Cell. 1995;80(1):155\u0026ndash;65. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/0092-8674(95)90460-3\u003c/span\u003e\u003cspan address=\"10.1016/0092-8674(95)90460-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLeckie J, Yokota T. Potential of Cell-Penetrating Peptide-Conjugated Antisense Oligonucleotides for the Treatment of SMA. Molecules. 2024;29(11):2658. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/molecules29112658\u003c/span\u003e\u003cspan address=\"10.3390/molecules29112658\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHoy SM. Nusinersen: A Review in 5q Spinal Muscular Atrophy. CNS Drugs. 2021;35(12):1317\u0026ndash;28. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s40263-021-00889-8\u003c/span\u003e\u003cspan address=\"10.1007/s40263-021-00889-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFinkel RS, Chiriboga CA, Vajsar J, Day JW, Montes J, De Vivo DC, et al. Treatment of infantile-onset spinal muscular atrophy with nusinersen: a phase 2, open-label, dose-escalation study. Lancet. 2016;388(10063):3017\u0026ndash;26. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0140-6736(16)31408-8\u003c/span\u003e\u003cspan address=\"10.1016/S0140-6736(16)31408-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHagenacker T, Wurster CD, G\u0026uuml;nther R, Schreiber-Katz O, Osmanovic A, Petri S, Weiler M, et al. Nusinersen in adults with 5q spinal muscular atrophy: a non-interventional, multicentre, observational cohort study. Lancet Neurol. 2020;19(4):317\u0026ndash;25. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S1474-4422(20)30037-5\u003c/span\u003e\u003cspan address=\"10.1016/S1474-4422(20)30037-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHagenacker T, Maggi L, Coratti G, Youn B, Raynaud S, Paradis AD, Mercuri E. Effectiveness of Nusinersen in Adolescents and Adults with Spinal Muscular Atrophy: Systematic Review and Meta-analysis. Neurol Ther. 2024;13(5):1483\u0026ndash;1504. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s40120-024-00653-2\u003c/span\u003e\u003cspan address=\"10.1007/s40120-024-00653-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStolte B, Totzeck A, Kizina K, Bolz S, Pietruck L, M\u0026ouml;nninghoff C, et al. Feasibility and safety of intrathecal treatment with nusinersen in adult patients with spinal muscular atrophy. Ther Adv Neurol Disord. 2018;11:1756286418803246. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/1756286418803246\u003c/span\u003e\u003cspan address=\"10.1177/1756286418803246\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePechmann A, Langer T, Wider S, Kirschner J. Single-center experience with intrathecal administration of Nusinersen in children with spinal muscular atrophy type 1. Eur J Paediatr Neurol. 2018;22(1):122\u0026ndash;27. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ejpn.2017.11.001\u003c/span\u003e\u003cspan address=\"10.1016/j.ejpn.2017.11.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWijngaarde CA, Brink RC, de Kort FAS, Stam M, Otto LAM, Asselman FL, et al. Natural course of scoliosis and lifetime risk of scoliosis surgery in spinal muscular atrophy. Neurology. 2019;93(2):e149-e58. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1212/WNL.0000000000007742\u003c/span\u003e\u003cspan address=\"10.1212/WNL.0000000000007742\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCordts I, Lingor P, Friedrich B, Pernpeintner V, Zimmer C, Deschauer M, Maegerlein C. Intrathecal nusinersen administration in adult spinal muscular atrophy patients with complex spinal anatomy. Ther Adv Neurol Disord. 2020;13:1756286419887616. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/1756286419887616\u003c/span\u003e\u003cspan address=\"10.1177/1756286419887616\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMadan E, Carri\u0026eacute; S, Donado C, Lobo K, Souris M, Laine R, et al. Nusinersen for Patients With Spinal Muscular Atrophy: 1415 Doses via an Interdisciplinary Institutional Approach. Pediatr Neurol. 2022;132:3340. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.pediatrneurol.2022.04.008\u003c/span\u003e\u003cspan address=\"10.1016/j.pediatrneurol.2022.04.008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eInternational Commission on Radiological Protection. The 2007 recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP. (2007) 37, 1\u0026ndash;332. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.icrp.2008.07.001\u003c/span\u003e\u003cspan address=\"10.1016/j.icrp.2008.07.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWurster CD, Winter B, Wollinsky K, Ludolph AC, Uzelac Z, Witzel S, et al. Intrathecal administration of nusinersen in adolescent and adult SMA type 2 and 3 patients. J Neurol. 2019;266(1):183\u0026ndash;94. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00415-018-9124-0\u003c/span\u003e\u003cspan address=\"10.1007/s00415-018-9124-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCordts I, Deschauer M, Lingor P, Burian E, Baum T, Zimmer C, et al. Radiation dose reduction for CT-guided intrathecal nusinersen administration in adult patients with spinal muscular atrophy. Sci Rep. 2020;10(1):3406. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-020-60240-x\u003c/span\u003e\u003cspan address=\"10.1038/s41598-020-60240-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMousa MA, Aria DJ, Schaefer CM, Kaye RD, Abruzzo TA, Bernes SM, et al. A comprehensive institutional overview of intrathecal nusinersen injections for spinal muscular atrophy. Pediatr Radiol. 2018;48(12):1797\u0026ndash;1805. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00247-018-4206-9\u003c/span\u003e\u003cspan address=\"10.1007/s00247-018-4206-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMendon\u0026ccedil;a RH, Fernandes HDS, Pinto RBS, Matsui J\u0026uacute;nior C, Polido GJ, Silva AMSD, et al. Managing intrathecal administration of nusinersen in adolescents and adults with 5q-spinal muscular atrophy and previous spinal surgery. Arq Neuropsiquiatr. 2021;79(2):127\u0026ndash;32. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1590/0004-282X-ANP-2020-0200\u003c/span\u003e\u003cspan address=\"10.1590/0004-282X-ANP-2020-0200\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKizina K, Stolte B, Totzeck A, Bolz S, Fleischer M, M\u0026ouml;nninghoff C, et al. Clinical Implication of Dosimetry of Computed Tomography- and Fluoroscopy-Guided Intrathecal Therapy With Nusinersen in Adult Patients With Spinal Muscular Atrophy. Front Neurol. 2019;10:1166. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3389/fneur.2019.01166\u003c/span\u003e\u003cspan address=\"10.3389/fneur.2019.01166\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSpiliopoulos S, Reppas L, Zompola C, Palaiodimou L, Papadopoulou M, Filippiadis D, et al. Computed-tomography-guided transforaminal intrathecal nusinersen injection in adults with spinal muscular atrophy type 2 and severe spinal deformity. Feasibility, safety and radiation exposure considerations. Eur J Neurol. 2020;27(7):1343\u0026ndash;49. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/ene.14245\u003c/span\u003e\u003cspan address=\"10.1111/ene.14245\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWeaver JJ, Hallam DK, Chick JFB, Vaidya S, Shin DS, Natarajan N, Rad N, et al. Transforaminal intrathecal delivery of nusinersen for older children and adults with spinal muscular atrophy and complex spinal anatomy: an analysis of 200 consecutive injections. J Neurointerv Surg. 2021;13(1):75\u0026ndash;78. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/neurintsurg-2020-016058\u003c/span\u003e\u003cspan address=\"10.1136/neurintsurg-2020-016058\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTowbin R, Schaefer C, Kaye R, Abruzzo T, Aria DJ. The Complex Spine in Children with Spinal Muscular Atrophy: The Transforaminal Approach-A Transformative Technique. AJNR Am J Neuroradiol. 2019;40(8):1422\u0026ndash;26. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3174/ajnr.A6131\u003c/span\u003e\u003cspan address=\"10.3174/ajnr.A6131\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJochmann E, Steinbach R, Jochmann T, Chung HY, R\u0026ouml;diger A, Neumann R, et al. Experiences from treating seven adult 5q spinal muscular atrophy patients with Nusinersen. Ther Adv Neurol Disord. 2020;13:1756286420907803. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/1756286420907803\u003c/span\u003e\u003cspan address=\"10.1177/1756286420907803\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBevelacqua, J. J. Practical and effective ALARA. Health Phys. 98(Suppl 2), S39\u0026ndash;47.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePrasad, K. N., Cole, W. C. \u0026amp; Haase, G. M. Radiation protection in humans: extending the concept of as low as reasonably achievable (ALARA) from dose to biological damage. Br. J. Radiol. 77, 97\u0026ndash;99. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1259/bjr/88081058\u003c/span\u003e\u003cspan address=\"10.1259/bjr/88081058\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOldenburg D, Guberina N, Stolte B, Kizina K, Stenzel E, et al. Radiation exposure of image-guided intrathecal administration of nusinersen to adult patients with spinal muscular atrophy. Neuroradiology. 2019;61(5):565\u0026ndash;74. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00234-019-02189-x\u003c/span\u003e\u003cspan address=\"10.1007/s00234-019-02189-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVeerapandiyan A, Pal R, D'Ambrosio S, Young I, Eichinger K, Collins E, Westesson PL, Kwon J, Ciafaloni E. Cervical puncture to deliver nusinersen in patients with spinal muscular atrophy. Neurology. 2018;91(7):e620-e24. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1212/WNL.0000000000006006\u003c/span\u003e\u003cspan address=\"10.1212/WNL.0000000000006006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWei C, Liang Z, Wu Y, Liu S, Qiu J, Meng L, et al. Ultrasound-guided interlaminar approach for nusinersen administration in patients with spinal muscular atrophy with spinal fusion or severe scoliosis. Orphanet J Rare Dis. 2023;18(1):30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1186/s13023-023-02630-8\u003c/span\u003e\u003cspan address=\"10.1186/s13023-023-02630-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOrtiz CB, Kukreja KU, Lotze TE, Chau A. Ultrasound-guided cervical puncture for nusinersen administration in adolescents. Pediatr Radiol. 2019;49(1):136\u0026ndash;40. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00247-018-4240-7\u003c/span\u003e\u003cspan address=\"10.1007/s00247-018-4240-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic and clinical characteristics of the study cohort.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eValue\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of patients\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e44\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian Age (range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e31 years (14\u0026ndash;58 years)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGender\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e23 male (52.3%), 21 female (47.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDorsal spondylodesis present\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e21 patients (47.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal number of interventions performed\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e458\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSMA type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e- Type 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e3 patients (6.8%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e- Type 2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003e28 patients (63.6%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e- Type 3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e13 patients (29.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colspan=\"1\" nameend=\"c3\" namest=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of procedural parameters between patients with and without dorsal spondylodesis.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eWith dorsal spondylodesis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eWithout dorsal spondylodesis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of procedures\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e208 (45.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e250 (54.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026ndash;\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTechnically successful procedures\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e202 (97.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e247 (98.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.311\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePuncture duration (median, range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11.9 min (2.8\u0026ndash;96.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.3 min (1.6\u0026ndash;76.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0031\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProcedure duration (median, range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e16.3 min (7.4\u0026ndash;102.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14.0 min (5.1\u0026ndash;134.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.0028\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eOverview of periprocedural complications.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eType of complication\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eProportion of all interventions (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePain\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeedle tract hematoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.2%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRetroperitoneal hematoma\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e0.2%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAll complications\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.1%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eComparison of key intervention parameters for all procedures, procedures with complications and technically unsuccessful procedures.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAll interventions\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;458)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInterventions with complications\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;5)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eUnsuccessful interventions\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;9)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian number of repositioning attempts (IQR, range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0\u0026ndash;0, 0\u0026ndash;5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (1\u0026ndash;2, 0\u0026ndash;4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (0\u0026ndash;2, 0\u0026ndash;5)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian puncture duration (IQR, range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e11.1 min (7.7\u0026ndash;16.2, 1.6\u0026ndash;96.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e55.8 min (55.1\u0026ndash;76, 20.9\u0026ndash;95.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e52.2 min (33.4\u0026ndash;65.8, 18.4\u0026ndash;96.6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMedian procedure duration (IQR, range)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e14.8 min (10.9\u0026ndash;20.8, 5.1-134.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e59.7 min (59.1\u0026ndash;81.9, 41.7-102.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e58.4 min (45.9\u0026ndash;69.7, 22.2-102.9)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDorsal spondylodesis (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e202 (44,1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (80.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6 (66,7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eTechnical success rates by patient positioning.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePatient positioning\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eNumber of procedures\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNumber of successful procedures\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSuccess rate (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProne position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e44 (9.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e43\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e97.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft lateral position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e233 (50.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e228\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e97.9%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight lateral position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e165 (36.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e162\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e98.2%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight lateral/prone position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e15 (3.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e100%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft lateral/prone position\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (0.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e100%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRadiation exposure.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eParameters\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTotal procedures\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eProcedures with dorsal spondylodesis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eProcedures without dorsal spondylodesis\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eUnsuccessful\u003c/p\u003e\u003cp\u003eprocedures\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eInterventions with complications\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCTDIvol (median, IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8.67 (5.76\u0026ndash;13.62)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e9.68 (7.53\u0026ndash;13.92)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e7.24 (4.12\u0026ndash;12.64)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e17.80 (8.58\u0026ndash;30.87)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e9.78 (5.08\u0026ndash;22.50)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDLP (median, IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e120.99 (74.73-218.36)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e141.75 (94.81-239.92)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e104.66 (58.66-191.14)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e414.38 (119.27\u0026ndash;598.70)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e414.38 (211.65-446.61)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEffective dose (median, IQR)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2.02 (1.35\u0026ndash;3.17)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e2.22 (1.60\u0026ndash;3.25)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e1.74 (1.08\u0026ndash;3.04)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e4.25 (2.54\u0026ndash;7.69)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.82 (3.45\u0026ndash;4.25)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"6\"\u003eCTDI: Computed Tomography Dose Index; DLP\u0026thinsp;=\u0026thinsp;Dose-Length Product\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Spinal muscular atrophy (SMA), Nusinersen, Intrathecal drug administration, CT-guided lumbar puncture, Radiation exposure, Dose optimization","lastPublishedDoi":"10.21203/rs.3.rs-7722326/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7722326/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003ePurpose\u003c/strong\u003e\u003cbr\u003e\nSpinal muscular atrophy (SMA) is a rare neuromuscular disease treated with intrathecal nusinersen. In patients with complex spinal anatomy or spinal instrumentation, repeated lumbar punctures can be challenging. CT guidance is a valuable alternative. This study evaluated feasibility, safety, and radiation exposure of CT-guided nusinersen administration in SMA.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003cbr\u003e\nIn this retrospective single-center study, 458 CT-guided nusinersen injections performed in 44 SMA patients between October 2017 and August 2024 were analyzed. Technical success, complications, procedure times, and radiation exposure were assessed between subgroups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003cbr\u003e\nOverall technical success was 98.3% (449/458). Success rates were slightly lower in patients with dorsal spondylodesis (97.1% vs. 98.8%, p=0.311). Complications occurred in 1.1% (5/458). Patients with spondylodesis had significantly longer puncture (median 11.9 vs. 10.3 min, p=0.0031) and procedure durations (16.3 vs. 14.0 min, p=0.0028) and higher radiation doses (CTDIvol 9.68 vs. 7.24 mGy, DLP 142 vs. 105 mGy·cm, effective dose 2.22 vs. 1.74 mSv; all p\u0026lt;0.0001). Failed or complicated procedures were linked to prolonged durations (p\u0026lt;0.0001) and higher radiation exposure. Needle repositioning was more frequent in spondylodesis, failed, and complicated cases, and correlated with duration and radiation dose. Technical success was independent of patient positioning.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003cbr\u003e\nCT-guided lumbar puncture for intrathecal nusinersen injection is a safe and effective technique, even in patients with complex spinal anatomy. Dorsal spondylodesis increases complexity, reflected by longer durations, more repositioning, and higher radiation exposure. Tailored puncture level selection, optimized positioning, and dose-reduction strategies are essential for high success rates and minimizing radiation burden in long-term SMA therapy.\u003c/p\u003e","manuscriptTitle":"CT-guided Lumbar Puncture for Intrathecal Nusinersen Injection in Patients with Spinal Muscular Atrophy: Technical Effectiveness, Safety, and Radiation Dose","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 02:21:59","doi":"10.21203/rs.3.rs-7722326/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"be815a9a-fea8-4574-b430-70f7b605a066","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:01:54+00:00","versionOfRecord":{"articleIdentity":"rs-7722326","link":"https://doi.org/10.1007/s00062-025-01590-9","journal":{"identity":"clinical-neuroradiology","isVorOnly":false,"title":"Clinical Neuroradiology"},"publishedOn":"2025-11-25 15:57:40","publishedOnDateReadable":"November 25th, 2025"},"versionCreatedAt":"2025-10-17 02:21:59","video":"","vorDoi":"10.1007/s00062-025-01590-9","vorDoiUrl":"https://doi.org/10.1007/s00062-025-01590-9","workflowStages":[]},"version":"v1","identity":"rs-7722326","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7722326","identity":"rs-7722326","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}