Thermal Ablation vs. Conventional Neck Dissection for Recurrent Low-Burden Lymph Node Metastasis in Thyroid Cancer: A Dual-Center Retrospective Cohort Study

Thermal Ablation vs. Conventional Neck Dissection for Recurrent Low-Burden Lymph Node Metastasis in Thyroid Cancer: A Dual-Center Retrospective Cohort Study | 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 Article Thermal Ablation vs. Conventional Neck Dissection for Recurrent Low-Burden Lymph Node Metastasis in Thyroid Cancer: A Dual-Center Retrospective Cohort Study Xiaojian Ye, Yan lei, Jinshu zeng, Jianchuan Yang, Lingpeng Tang, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7272514/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Objective: To compare ultrasound-guided thermal ablation (TA) with conventional neck dissection (CND) for recurrent low-burden lymph node metastasis (≤3 lesions, <2 cm) in thyroid cancer, aiming to guide precision therapy. Methods: A dual-center retrospective study (2016–2022) analyzed 230 patients with recurrent lymph node metastasis, stratified into TA ( n = 115) and reoperation groups ( n = 115). Endpoints included recurrence-free survival, complications, thyroglobulin (Tg) dynamics, quality of life (EORTC QLQ-C30), and healthcare costs. Results: Oncological Outcomes: No significant difference in 36-month recurrence rates (Log-rank p = 0.54; Bonferroni-corrected p = 1.00). Safety: Similar complication rates (nerve injury, hypocalcemia, hematoma, infection; all p > 0.7). TA Advantages: Shorter operative time, less blood loss, faster recovery, shorter hospital stays, and lower costs. 50% of TA-treated patients achieved complete lymph node volume reduction (100% VRR) within 36 months. Conclusion: TA demonstrates non-inferior oncological efficacy to CND for strictly selected patients with recurrent low-burden lymph node metastasis, offering minimally invasive precision therapy with superior procedural efficiency and quality-of-life benefits. Biological sciences/Cancer Health sciences/Oncology Thermal Ablation Neck Dissection Recurrent Papillary Thyroid Carcinoma Lymph Node Metastasis Low-Burden Lymph Nodes Quality of Life Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Introduction Papillary thyroid carcinoma (PTC) accounts for over 85% of thyroid malignancies. Although surgical resection (total thyroidectomy + lymphadenectomy) achieves a 5-year survival rate of 98.5% [1], postoperative recurrence remains high, with cervical lymph node metastasis (LNM) being the most common form [2]. Treatment options for recurrent disease primarily include three approaches: secondary surgery, active surveillance, and radioactive iodine therapy. However, each carries distinct risks. These include: increased complication rates for secondary surgery, particularly in hospitals with lower surgical volumes [3]; more than double the risk of permanent vocal cord paralysis [4,5]; progression risks associated with active surveillance (AS), along with significant physical and psychological burdens compared to the general population [6]; and radioactive iodine therapy (RAI) induced side effects, such as bone marrow suppression and salivary gland damage, with sialadenitis occurring in over 20% of cases [7,8]. The emergence of ultrasound-guided thermal ablation (TA) offers a minimally invasive solution for recurrent LNM. TA induces coagulative necrosis in tumors via thermal effects (60–100°C) and enables precise targeting under high-resolution ultrasound guidance, with established efficacy in thyroid tumors [9]. However, studies on TA for recurrent thyroid cancer, especially in low-burden lymph node metastasis, are limited, and comparative analyses with conventional surgery remain scarce. This study aims to conduct a dual-center retrospective cohort analysis to systematically evaluate differences between TA and neck dissection in tumor control, safety, quality of life, and socioeconomic outcomes, providing evidence-based guidance for stratified treatment of recurrent thyroid cancer. Methods 1.1 Study Design This study was a dual-center retrospective cohort study, conducted in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Ethical approval was obtained from the Institutional Review Board [Approval No.: MTCA, ECFAH of FMU (2015) 084 − 2], with waiver of informed consent. 1.2 Participants 1.2.1 Patient Selection A total of 512 patients with recurrent thyroid cancer presenting with lymph node metastasis, treated at two centers between January 2016 and April 2022, were screened. The final analysis included 230 patients: 115 in the thermal ablation group (TAG) and 115 in the reoperation group (RSG) (Fig. 1 ). 1.2.2 Inclusion and Exclusion Criteria Inclusion Criteria ① Diagnosis confirmed by fine needle aspiration cytopathology or surgical histology as PTC with cervical lymph node metastasis; ② ≤3 metastatic lesions, with the largest lesion < 2 cm in diameter; ③ Completion of standardized 36-month follow-up, including psychological assessment at postoperative month 1, with complete clinical and data records. Exclusion Criteria ① Patients receiving palliative treatment; ② History of prior cervical radiotherapy; ③ Concurrent diagnosis of other malignancies. 1.2.3 Follow-Up Principles The total follow-up period was 36 months, with scheduled follow-ups at postoperative months 1, 3, 6, 9, 12, 18, 24, 30, and 36. Follow-ups were conducted via in-person clinical visits. A psychological assessment was performed at the first postoperative month. At each follow-up visit, ultrasound examinations and serum thyroglobulin (Tg) tests were conducted. For the thermal ablation group (TAG), target lymph nodes were measured using preoperative imaging as the dimensional reference, including three-dimensional diameters. Clear images were retained to calculate the volume reduction ratio (VRR): VRR (%) = (Initial Volume − Final Volume) / Initial Volume × 100% . Two imaging experts, blinded to group allocation, independently evaluated the quality of follow-up imaging. Consensus-based standardized measurements were performed for disputed imaging data. For the ablation group, at least one contrast-enhanced ultrasound examination was included in the 36-month follow-up. 1.3 Interventions 1.3.1 RSG (n = 115) All enrolled patients underwent lymph node dissection based on the nodal classification of the 8th edition of the AJCC. Central compartment dissection included levels VI + VII (inferior boundary: innominate artery); lateral neck dissection included levels IIa, III, IV, and Vb (with preservation of the accessory nerve). Intraoperative neuromonitoring (IONM) followed the guidelines of the International Neuromonitoring Study Group (INMSG) to protect the recurrent laryngeal nerve. En bloc resection was performed to ensure negative margins, and functional neck dissection preserved non-lymphatic structures. 1.3.2 TAG (n = 115) All procedures were performed by interventional physicians with > 5 years of experience (annual surgical volume ≥ 50 cases). Preoperatively, patients and their families were thoroughly informed about the surgical approach, process, and details, and received comforting psychological counseling to minimize anxiety. Patients underwent training for respiratory control, swallowing suppression, and cough management during airway stimulation. Procedures were conducted under local anesthesia, ensuring patient consciousness. Sedation was administered only when cooperation difficulties arose. Continuous electrocardiogram monitoring was maintained throughout. Microwave ablation (MWA) was performed under high-resolution ultrasound guidance. A ≥ 5 mm fluid isolation zone (using saline or 5% glucose) was created around the ablation target to protect adjacent tissues. To prevent absorption of the isolation fluid during prolonged procedures, supplemental bolus injections or continuous infusion under pressure were administered. Operation mode and energy parameters: Fixed-position ablation was prioritized. For larger targets, multiple fixed-position ablations followed a "distal-to-proximal, deep-to-superficial" principle. Single-point energy settings: Central compartment: 25–30 W × 90 seconds; Lateral neck: 30–35 W × 60 seconds. Real-time two-dimensional imaging monitored ablation boundaries. Post-procedure, multimodal ultrasound imaging (contrast-enhanced ultrasound and elastography) assessed ablation completeness. Residual areas underwent immediate supplemental ablation until therapeutic standards were met (Figure 2 shows a complete ablation case). 1.3.3 Special Management Guidelines All patients with BRAF mutation were administered TSH suppressive therapy (target TSH level: <0.1 mU/L). 1.4 Outcomes Primary Outcomes: Disease progression, defined as: (1) Confirmed cervical recurrent tumor via FNA or histology; (2) Distant metastasis. The recurrence-free survival (RFS) was calculated from the date of surgery to the time of disease progression or the last follow-up visit. Secondary Outcomes Included: (1) Surgical time and intraoperative blood loss; (2) Postoperative complications; (3) Changes in postoperative thyroglobulin (Tg); (4) Volume reduction ratio (VRR) of ablated lymph nodes; (5) Hospitalization costs and length of stay; (6) Psychological assessment results at 1 month post-surgery. 1.5 Statistical Analysis 1.5.1 Dataset Processing Propensity score matching was performed to control for confounding bias, with 1:1 matching based on age (± 3 years), sex, and tumor size (± 0.2 cm), using a caliper of 0.02. Post-matching balance assessment of covariates was conducted using standardized mean differences (SMD < 0.1). 1.5.2 Statistical Testing Methods Continuous variables, confirmed as non-normally distributed via the Shapiro-Wilk test, were described as median (interquartile range, IQR). Group comparisons used the Wilcoxon rank-sum test, reporting Hodges-Lehmann median difference estimates and their 95% confidence intervals (CI). Effect size was quantified using Cliff’s delta (|δ| ≥ 0.66 indicated a large effect). Categorical variables were described as frequency (percentage), with group comparisons analyzed by Fisher’s exact test. Relative risks (RR) and their 95% CIs were calculated. Bonferroni correction was applied for multiple comparisons, with adjusted p -values > 0.05 considered statistically non-significant. All analyses were performed using R version 4.5.0, with a significance level of α = 0.05. Results 2.1 Baseline Characteristics After propensity score matching, baseline characteristics were balanced between the two groups, with all variables showing SMD < 0.1 (the largest SMD in this study was 0.092), indicating successful matching and good comparability. Subsequent efficacy analysis could be conducted (Table 1 ). Table 1 Table of Baseline Characteristics Comparison After Propensity Score Matching (Including Standardized Differences) Variable TAG Group (n = 115) RSG Group (n = 115) SMD p-value Age (years) 43.8 ± 14.2 42.7 ± 13.8 0.021 0.527 Female sex 63 (54.8%) 60 (52.2%) 0.052 0.692 Lymph node compartment 0.041 0.831 • Central (CNC) 34 (29.6%) 33 (28.7%) • Lateral (LNC) 61 (53.0%) 64 (55.7%) • CNC + LNC 20 (17.4%) 18 (15.6%) No. of MLNs 1.5 ± 0.7 1.7 ± 0.7 0.092 0.023 Max diameter (cm) 1.12 ± 0.42 1.12 ± 0.38 0.003 0.935 BRAF V600E positive 82 (71.3%) 79 (68.7%) 0.056 0.668 Tg level (ng/mL) 12.4 ± 18.5 10.2 ± 16.9 0.084 0.312 Propensity score 0.59 ± 0.16 0.61 ± 0.15 0.074 0.285 2.2 Comparison of Cumulative Recurrence Rates within 36 Months Based on 36-month follow-up data, 7 cases of disease progression were observed in the RSG group, while the TAG group reported 5 cases. The characteristics of patients with recurrence in both groups are detailed in Table 2 . There was no significant difference in relapse-free survival rates between the RSG and TAG groups (Log-rank p = 0.54; Fig. 3 ). Table 2. Table of Summary of Characteristics of Recurrence Patients RSG (N=7) TAG (N=5) Age Mean (SD) 47.7 (11.8) 45.6 (12.1) Median [Min, Max] [32.0,64.0] 46.0 44.0 [31.0, 64.0] Gender Male 1 (14.3%) 3 (60.0%) Female 6 (85.7%) 2 (40.0%) Compartment CNC 2 (28.6%) 1 (20.0%) LNC 4 (57.1%) 4 (80.0%) Both 1 (14.3%) 0 (0%) Num_MLNs Mean (SD) 1.71 (0.951) 1.00 (0) Median [Min, Max] 1.00 [1.00, 3.00] 1.00 [1.00, 1.00] Max Diameter Mean (SD) 1.09 (0.170) 1.41(0.365) Median [Min, Max] 1.06 [0.900, 1.40] 1.22 [1.10, 1.98] BRAF V600E Negative 1 (14.3%) 0 (0%) Positive 6 (85.7%) 5(100%) Tg Mean (SD) 4.87 (8.21) 13.5 (13.9) Median [Min, Max] 1.85 [0.0400,23.1] 7.57 [0.0400, 33.4] The cumulative recurrence rates were 6.0% (n = 7/115) for the RSG group and 4.3% (n = 5/115) for the TAG group, with an absolute difference of 1.7% between the groups (Fig. 4 − 1). The relative risk (RR) was 1.39 (95% CI: 0.45–4.33) (Fig. 4 − 2), and the p -value was 0.56. After Bonferroni correction, the p -value remained 1.00, indicating no statistically significant difference in recurrence rates between the two groups. 2.3 Comparison of Surgery Time and Intraoperative Blood Loss between the RSG and TAG Groups The surgery time in the RSG group was significantly longer than that in the TAG group ( p < 0.001), with an extremely large effect size ( δ = 0.94, 95% CI: 0.88–0.97; Fig. 5 A). For intraoperative blood loss, the RSG group exhibited significantly higher volumes compared to the TAG group ( p < 0.001), with a large effect size ( δ = 0.90, 95% CI: 0.85–0.94; Fig. 5 B). 2.4 Postoperative Major Complications The primary postoperative complications analyzed in this study included transient/permanent recurrent laryngeal nerve injury, transient/permanent hypocalcemia, postoperative hematoma, and infection. The incidence of complications in each group is presented in Fig. 6 . Specifically: Transient recurrent laryngeal nerve injury was more frequent in the TAG group (5.2% vs. 2.6%, p = 0.42); Infection occurred exclusively in the RSG group (1.7% vs. 0%, p = 0.50); Postoperative hematoma was more common in the RSG group (2.6% vs. 0.9%, p = 0.44); Permanent hypocalcemia was observed only in the RSG group (0.9% vs. 0%, p = 1.00). After Bonferroni correction, no statistically significant differences in complication rates were found between the two groups (corrected p > 0.7). 2.5 Calculation of Volume Reduction Ratio (VRR) At the 36-month follow-up, the average VRR of the targeted lymph nodes reached 94.0% (Fig. 7 ), and no viable tissue was observed in the target lymph nodes during final contrast-enhanced imaging. Among these, the proportion of patients with VRR reaching 100% increased to 2.59% at approximately 18 months, rose significantly to 15.52% at 24 months, and ultimately reached 47.41% by 36 months post-surgery (Fig. 8 ). 2.6 Changes in Tg between the RSG and TAG Groups Overall Trend Analysis (Figs. 9 − 1 and 9 − 2): RSG group (orange): Tg levels significantly decreased in the early postoperative period (0–3 months) and stabilized after 6 months, maintaining a median value below 1 ng/mL. The trajectory followed a "rapid decline → stable maintenance" pattern. TAG group (blue): Tg levels decreased more gradually, with higher values still observed at 3 months postoperatively. The median approached 1 ng/mL only after 12 months, exhibiting a "gradual decline" pattern. The RSG group achieved and maintained low Tg levels (< 1 ng/mL) faster than the TAG group; however, the RSG group had inherently lower baseline Tg levels, which may introduce bias into the results. Both groups maintained stable Tg levels during the 18–36-month postoperative period, but the RSG group retained significantly lower median values (< 0.04 ng/mL), while the TAG group remained above 0.2 ng/mL. 2.7 Quality of Life At 1 month postoperatively, the EORTC QLQ-C30 score in the TAG group was significantly higher than that in the RSG group [82.8 ± 5.5 vs. 73.1 ± 7.8; mean difference = 9.7, 95% CI: 7.9–11.5; t (205.6) = 11.42, p < 0.001, Cohen’s d = 1.42] (Fig. 10 ). 2.8 Health Economics The hospital stay in the TAG group was significantly shorter than that in the RSG group (Fig. 11 ), with a mean difference of 7.2 days ( p < 0.001). Notably, 91.3% of patients in the TAG group had a hospital stay of only 1 day. Regarding hospitalization costs, the RSG group incurred an average cost of 22,867 RMB (median: 17,534 RMB). In contrast, the local health insurance reimbursement system for the TAG group used a Diagnosis-Related Group (DRG) payment model with a capped fee of 12,000 RMB. Consequently, hospitalization costs in the TAG group were significantly lower than those in the RSG group. Discussion Low burden lymph node metastasis is an important concept in the clinical management of thyroid cancer, particularly papillary thyroid carcinoma (PTC), typically referring to cases with a small number of metastatic lymph nodes (≤ 3) or minute metastatic foci [10,11]. The ATA (American Thyroid Association) guidelines suggest that for low-burden lymph nodes—especially those with a maximum diameter ≤ 8 mm and annual growth rate < 3–5 mm/year—active surveillance can be adopted if there is no proximity to or invasion of critical structures such as the recurrent laryngeal nerve or trachea. However, in real-world practice, this approach may cause significant psychological burden for patients, potentially leading to somatic symptoms like fatigue. A three-year survey of 2,454 patients with differentiated thyroid cancer (DTC) reported a 4.1% recurrence rate among treated individuals. Although psychological well-being scores among relapsed patients showed only minor differences compared to those with persistent thyroid cancer lesions, both groups exhibited significantly lower mental health levels than the general population [12]. Adjuvant radioactive iodine therapy (RAI) has been shown in prior retrospective studies [13–15] and a recent randomized trial [16] to not reduce recurrence rates in low-risk thyroid cancer patients during 3-year follow-up. In a randomized controlled trial involving 750 patients [16], the recurrence rate was 4.1% in the RAI-treated group versus 4.4% in the non-RAI group (difference: -0.3 [90% CI, -2.7 to 2.2]). This observation may be attributed to intrinsic radioiodine resistance in a subset of patients, raising doubts about the reliability of RAI in recurrent cancer treatment. Additionally, RAI carries risks of secondary hematologic malignancies and salivary gland dysfunction, which could adversely impact patients' quality of life. Ultrasound-guided thermal ablation is an effective treatment modality for solid tumors, achieving surgical-equivalent local control through instant high-temperature induction of protein denaturation, nucleic acid destruction, and microvascular embolization in tumor cells. Standardized operational protocols have been well established for its application in thyroid neoplasms and cervical lymph node metastasis, particularly in East Asia where thermal ablation techniques were pioneered and widely adopted, with relevant expert consensuses already published [17–19]. However, evidence regarding its therapeutic role in recurrent thyroid cancer with low-burden lymph node metastasis, as well as comparative studies with repeat surgery, remains relatively scarce. Our research findings provide compelling evidence to address this knowledge gap. The microwave ablation (MWA) procedure employed in this study represents a prevalent thermal ablation technology, characterized by high thermal efficiency, excellent thermal field conformality, and a short active tip of the microwave antenna, making it particularly well-suited for small tumor applications. The results of this study indicate that there was no significant difference in the cumulative recurrence rate within 36 months between the thermal ablation group and the reoperation group (p = 0.56, p = 1.00 after Bonferroni correction), demonstrating that thermal ablation is as effective as reoperation in controlling recurrent lesions. Although no statistically significant difference in cumulative recurrence rate was observed between the groups in this study, we found that the cumulative recurrence proportion in the reoperation group was higher than that in the thermal ablation group. This difference may be attributed to: (1) Incomplete resection of lesions, increased bleeding during the second operation, and limited visual field caused by scars from previous surgeries, leading to incomplete resection of lesions [20]; (2) Increased bleeding and the greater trauma associated with open surgery enhance the opportunity for tumor dissemination. Thermal ablation is performed under high-resolution ultrasound guidance, allowing real-time monitoring of the ablation process and immediate post-procedure assessment of the ablation area. Moreover, due to its minimally invasive nature and the thermal field covering the needle track, thermal ablation minimizes the risks of incomplete tumor destruction and needle track seeding. In this study, thermal ablation demonstrated superior performance compared to the reoperation group in terms of operative duration and intraoperative blood loss control. This advantage arises from severe inter-tissue adhesion in reoperation patients, where surgical procedures rely on visual identification by surgeons. The blurred structural demarcation of tissue layers increases operative difficulty, leading to prolonged surgical time and heightened risk of vascular injury during dissection [20,21]. Regarding postoperative complication rates—including transient recurrent laryngeal nerve injury, permanent recurrent laryngeal nerve injury, transient hypocalcemia, permanent hypocalcemia, postoperative hematoma, and infection—no statistically significant differences were observed between the thermal ablation group (TAG) and reoperation group (RSG). During open surgery, neurological structure differentiation and dissection become challenging due to tissue adhesion [20,21]; however, real-time intraoperative neural monitoring effectively mitigates nerve injury risks [22,23]. Although thermal ablation lacks a neural monitoring system akin to open surgery, high-resolution ultrasound assistance facilitates neural tissue differentiation [24,25]. Additionally, the hydrodissection technique employs injection pressure to precisely dissect adherent tissues and establishes a liquid barrier between the ablation target and critical structures, isolating thermal conduction and ensuring peripheral tissue safety [26]. Despite no statistical difference in recurrent laryngeal nerve injury incidence between groups, TAG exhibited a higher absolute count of transient injuries, primarily manifesting as low-pitched voice hoarseness without dysphagia or respiratory compromise, indicative of unilateral nerve involvement [27]. These cases typically resolved by the day following surgery, potentially attributable to local anesthetic infiltration or rapid tissue absorption of hydrodissection fluid without timely replenishment, causing minor thermal energy-induced damage [28]. Only one case of permanent hypocalcemia occurred in the RGS group, resulting from unintentional parathyroidectomy during central compartment lymph node dissection. To ensure maximal margin safety, excessive redundant tissue removal based on visual inspection led to parathyroid misadventure [29]. While misremoved parathyroids can undergo heterotopic transplantation, survival cannot be guaranteed [30], a risk further compounded in reoperation settings due to increased anatomical complexity, elevating parathyroid damage and permanent hypocalcemia risks [31]. The RSG group also showed higher absolute numbers of infection and postoperative hematoma cases, likely due to greater surgical trauma and prolonged operative times associated with open surgery [32,33]. After thermal ablation, the ablated target lymph nodes gradually shrink over time, eventually disappearing completely or undergoing fibrous scarring. A meta-analysis [34] investigated the mean volume reduction rate (VRR) of lymph nodes after thermal ablation, revealing that the average VRR ranged from 77.9–99.4%, with variations dependent on the ablation modality, among which microwave ablation achieved the highest VRR. The VRR of target lymph nodes in this study fell within the range reported in previous research, at 36 months post-ablation, the mean VRR of target lymph nodes reached 94.0%, and contrast-enhanced imaging confirmed the absence of metabolic activity in all lymph nodes. Additionally, in our cohort, the proportion of patients with a VRR of 100% increased to 2.59% at approximately 18 months, rose significantly to 15.52% by 24 months, and further ascended to 47.41% by 36 months post-ablation. This indicates that significant changes manifest around 24 months post-treatment, suggesting that complete resolution of lesions is challenging to achieve in the early post-treatment period. The discrepancies in VRR values across studies likely stem not only from differences in ablation techniques but also from variability in boundary delineation of target structures and measurement dimensions among examiners. Our team recommends retaining preoperative imaging as a reference standard, using surrounding anatomical landmarks as anchors for image fusion to ensure consistent measurement planes in follow-up assessments. Furthermore, standardizing follow-up personnel and equipment can minimize systematic errors. While VRR is a straightforward, non-invasive metric effective for routine evaluation, contrast-enhanced imaging [35] for assessing lymph node viability carries greater diagnostic weight in follow-up, as it provides functional evaluation at the molecular imaging level. Regarding Tg level control, based on preoperative and 36-month postoperative follow-up observations, the RSG group demonstrated a more rapid and consistent biochemical remission advantage, particularly with significant differences during the critical postoperative period (3–12 months). This aligns with conclusions from previous related studies [36,37]; however, due to the lower baseline Tg levels in the RSG group in this study, there may be a bias in evaluating early control efficiency. Regarding long-term outcomes, both groups maintained stable states in the long term (> 18 months). Additionally, the higher proportion of persistently detectable Tg values (> 1 ng/mL) in the TAG group suggests that closer follow-up or adjuvant therapy may be required. Regarding patients' quality of life, thermal ablation therapy demonstrated advantages due to its rapid treatment process, absence of postoperative incision care requirements, shorter recovery time, and improved patient comfort and experience [38,39]. In this study, the significantly higher quality-of-life scores (EORTC QLQ-C30) observed in the TAG group at 1 month post-surgery clearly demonstrate this advantage compared to the reoperation group. Notably, the reoperation group and thermal ablation group exhibited significant differences in hospital stay duration, hospitalization costs, and overall public healthcare resource utilization. In this study, the thermal ablation group's average hospital stay and hospitalization costs were substantially lower than those of the reoperation group. While hospitalization costs may vary across regions due to policy differences, the marked reduction in hospital stay days in the ablation group significantly reduced public resource consumption and enhanced workforce efficiency maintenance. Limitations of the Study This study was retrospective with a relatively small sample size (n = 115 per group), which may have resulted in insufficient statistical power. Future studies with larger sample sizes are warranted to confirm these trends. Previous literature has reported that the peak recurrence period for papillary thyroid carcinoma may extend beyond 36 months [40,41,42] (due to limited research on re-recurrence after treated recurrence, only primary recurrence data were referenced here). The current study may have underestimated the probability of re-recurrence, and longer-term follow-up studies are anticipated to address this gap. Conclusion The results of this study confirm that in postoperative patients with recurrent low-burden lymph node metastasis of papillary thyroid carcinoma, thermal ablation can serve as a viable alternative to surgery due to its non-inferior oncological outcomes, comparable complication rates, shorter operative time, reduced intraoperative blood loss, superior short-term quality-of-life scores, and higher efficiency in workforce maintenance. However, its value extends beyond introducing a novel technique; it represents a paradigm shift in thyroid cancer treatment—transitioning from "maximum tolerated therapy" to "minimum effective intervention." Future prospective randomized controlled trials (RCTs) across multiple centers with larger cohorts are required to validate long-term efficacy. The ultimate goal is to provide personalized precision treatment options for patients stratified by risk, achieving the optimal balance between radical tumor control and quality of life. Declarations Ethics approvaland consent to participate: This study was approved by the Ethics Committee of First Affiliated Hospital of Fujian Medical University (Approval Number: MTCA, ECFAH of FMU [2015] 084-2) and granted an exemption from informed consent. All research procedures complied with the Declaration of Helsinki principles. We implemented rigorous measures to protect participants' privacy and data security, including complete anonymization of personal information to prevent identification. All research personnel had undergone ethics training. We hereby affirm our commitment to upholding the highest ethical standards throughout study conduct and reporting, thereby ensuring scientific rigor, equity, and ethical integrity. Availability of data and material ： The datasets generated and/or analysed during the current study are not publicly available due the funding agency's internal requirements for data management but are available from the corresponding author on reasonable request. Any requests for data must specify the required information in detail and state the purpose for which the data will be used. Competing interests: All authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted. Funding: This research was supported by the following fund: Provincial subsidy fund for health and wellness from Fujian Provincial Department of Finance (Grant number: BPB-2022YXJ). Author Contribution: Songsong Wu was responsible for the experimental design; Xiaojian Ye and Yan lei were responsible for data analysis and manuscript drafting; Jinshu zeng and Jianchuan Yang were responsible for data quality control; Lingpeng Tang, Xiaoying Lin, Xueqing Lin, Qi Zhong ang Yuqi Hong were responsible for data collection. Clinical trial number: not applicable. References Boucai, L., Zafereo, M., & Cabanillas, M. E. (2024). Thyroid Cancer: A Review. JAMA, 331(5), 425–435. https://doi.org/10.1001/jama.2023.26348 Chua, W. M., Tang, C. Y. L., Loke, K. S. H., Lam, W. W., Yang, S. P., Lee, M. S., Hou, W., Lim, M. Y. S., Lim, K. C., & Chen, R. C. (2024). Differentiated Thyroid Cancer after Thyroidectomy. Radiographics : a review publication of the Radiological Society of North America, Inc, 44(10), e240021. https://doi.org/10.1148/rg.240021 Huston-Paterson, H., Mao, Y., Tseng, C. H., Kim, J., Yeh, M. W., & Wu, J. X. (2023). 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I., & Kandil, E. (2025). Comparative efficacy, safety, and oncological outcomes of percutaneous thermal and chemical ablation modalities for recurrent metastatic cervical lymphadenopathy from thyroid cancer. Surgical oncology, 58, 102180. https://doi.org/10.1016/j.suronc.2024.102180 Rink, M., Jung, E. M., & Künzel, J. (2023). The Use of Contrast-Enhanced Sonography for Therapy Monitoring of Metastatic Lymph Nodes: A Systematic Review. Current oncology (Toronto, Ont.), 30(7), 6734–6743. https://doi.org/10.3390/curroncol30070494 Wan, Q., Tan, L., Tang, X., Wang, W., Su, Y., Wu, Z., Ke, M., & Chen, Z. (2024). The clinical value of iodine-125 seed implantation in the treatment of iodine-refractory differentiated thyroid carcinoma. Frontiers in endocrinology, 15, 1327766. https://doi.org/10.3389/fendo.2024.1327766 Yan, L., Yang, Z., Li, Y., Li, X., Xiao, J., Jing, H., & Luo, Y. (2023). 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Clinical outcomes of ultrasound-guided radiofrequency ablation for solitary T1N0M0 papillary thyroid carcinoma: A retrospective study with more than 5 years of follow-up. Cancer, 129(16), 2469–2478. https://doi.org/10.1002/cncr.34802 Yang, Z., Heng, Y., Zhao, Q., Hao, D., Tao, L., Deng, X., Cai, W., & Qiu, W. (2023). The proposed modification of TNM staging and therapeutic strategy for skip metastasis in papillary thyroid carcinoma: A multicenter retrospective cohort study. Cancer medicine, 12(12), 13270–13278. https://doi.org/10.1002/cam4.6018 Attia, A., Touma, E., Lussey-Lepoutre, C., Ghander, C., Jouinot, A., Roy, M., Housni, S., Chereau, N., Menegaux, F., Leenhardt, L., & Buffet, C. (2024). Consideration of Early Dynamic Risk Stratification to Guide Discharge from Oncologic Follow-Up in Patients with Differentiated Thyroid Cancer. Thyroid : official journal of the American Thyroid Association, 34(12), 1465–1475. https://doi.org/10.1089/thy.2024.0119 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted 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-7272514","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":515295657,"identity":"e1e3cc96-13db-48c3-a581-fc9c96f33f01","order_by":0,"name":"Xiaojian Ye","email":"","orcid":"","institution":"First Affiliated Hospital of Fujian Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xiaojian","middleName":"","lastName":"Ye","suffix":""},{"id":515295658,"identity":"68dec96f-ee11-42cf-af9d-cf49930532b1","order_by":1,"name":"Yan lei","email":"","orcid":"","institution":"First Affiliated Hospital of Fujian Medical 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11:29:20","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":202473,"visible":true,"origin":"","legend":"\u003cp\u003eThe image illustrates the complete treatment course and follow-up outcomes of a 62-year-old female patient. Figure A, B, and C respectively demonstrate the two-dimensional longitudinal view of the lymph node prior to microwave ablation (indicated by red arrows), the color Doppler longitudinal view (showing abundant and chaotic blood flow signals), and the color Doppler transverse view (revealing its location between the right common carotid artery and the trachea). The white arrows point to the right common carotid artery. Figures D and E illustrate the establishment of hydrodissection, with white arrows indicating the right common carotid artery, red arrows marking the lymph node, and blue arrows denoting the injection needle. In Figure E, an anechoic fluid isolation layer is observed between the lymph node and the right common carotid artery. Figure F shows the ablation process, with red arrows pointing to the lymph node covered by vaporization caused by thermal energy, and green arrows indicating the microwave antenna. Figure G presents the color Doppler longitudinal view of the lymph node (indicated by red arrows) immediately after thermal ablation, revealing no internal blood flow signals. Figure H displays the contrast-enhanced ultrasound longitudinal view of the lymph node (marked by red arrows) post-ablation, showing no contrast agent perfusion. Figure I presents a two-dimensional short-axis view of the operative field at the 24-month postoperative follow-up, revealing complete resolution of the targeted lymph node. The white arrow indicates the right common carotid artery.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/d1c53b71052c109c2900a7f8.jpg"},{"id":91525104,"identity":"3dd29c79-9f14-404d-8ec1-68567f921c66","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":64406,"visible":true,"origin":"","legend":"\u003cp\u003eRecurrence-Free Survival Curve\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/01d6d4bb0c325edb4606ec63.jpg"},{"id":91525106,"identity":"e9f4408a-9e63-40bc-b89f-29b06351c227","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":71210,"visible":true,"origin":"","legend":"\u003cp\u003e1: Recurrence Rate Comparison: TAG vs. RSG Groups\u003c/p\u003e\n\u003cp\u003e2: RSG vs. TAG: Recurrence Risk Comparison (Forest Plot)\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/f37d31ef1f8b7e8ed6185a92.jpg"},{"id":91525110,"identity":"0d2ecf9b-5708-42bc-a662-58a83665d807","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":80922,"visible":true,"origin":"","legend":"\u003cp\u003eRSG vs. TAG: Comparison of Surgical Duration and Blood Loss\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/a4f90f27ebc357fca9b3e263.jpg"},{"id":91525107,"identity":"30a955e0-ca61-4641-89ca-00d583543b50","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":48995,"visible":true,"origin":"","legend":"\u003cp\u003eRSG vs. TAG: Comparison of Complication Incidence\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/c6fd1c214b4854463c8ead00.jpg"},{"id":91525119,"identity":"f4fd1ef8-42b6-448f-8dc0-bee4c5bc712d","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":79347,"visible":true,"origin":"","legend":"\u003cp\u003eCurve of Volume Reduction Rate (VRR) Over Time\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/4a8f4534ffa9b842937f805c.jpg"},{"id":91527100,"identity":"c9a48eee-0a33-4240-8512-e34be11f185e","added_by":"auto","created_at":"2025-09-17 11:13:20","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":52141,"visible":true,"origin":"","legend":"\u003cp\u003eVRR=100% in the TAG Group Over Time\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/85d0a1623773a8807e3abbae.jpg"},{"id":91527103,"identity":"29f1cb62-3d50-4d0e-833f-665ee60c2a07","added_by":"auto","created_at":"2025-09-17 11:13:20","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":125378,"visible":true,"origin":"","legend":"\u003cp\u003e1: Thyroglobulin (Tg) Levels Over Time by Treatment Group\u003c/p\u003e\n\u003cp\u003e2: Tg Value Comparison Between TAG and RSG Groups\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/66f3097f040b2a9ec0dff553.jpg"},{"id":91525120,"identity":"03850ece-aae6-4faa-b81d-07a2f3d5a302","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":87209,"visible":true,"origin":"","legend":"\u003cp\u003eRSG vs. TAG: Comparison of EORTC Quality of Life Scores at 1 Month Post-surgery\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/b9dee4df74751714dc5ccba4.jpg"},{"id":91525118,"identity":"5b2a58ac-effc-462c-8a0f-f59980b23a57","added_by":"auto","created_at":"2025-09-17 11:05:20","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":107464,"visible":true,"origin":"","legend":"\u003cp\u003eComprehensive Comparison of Length of Stay Distribution Between RSG and TAG Groups\u003c/p\u003e","description":"","filename":"11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/653b7f86dc1a379cce03f41a.jpg"},{"id":93650994,"identity":"29361563-bb95-406a-9930-753308378b37","added_by":"auto","created_at":"2025-10-16 05:47:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2147169,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7272514/v1/d1661a7f-fe33-4772-b598-037ba775156a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Thermal Ablation vs. Conventional Neck Dissection for Recurrent Low-Burden Lymph Node Metastasis in Thyroid Cancer: A Dual-Center Retrospective Cohort Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePapillary thyroid carcinoma (PTC) accounts for over 85% of thyroid malignancies. Although surgical resection (total thyroidectomy + lymphadenectomy) achieves a 5-year survival rate of 98.5% [1], postoperative recurrence remains high, with cervical lymph node metastasis (LNM) being the most common form [2]. Treatment options for recurrent disease primarily include three approaches: secondary surgery, active surveillance, and radioactive iodine therapy. However, each carries distinct risks. These include: increased complication rates for secondary surgery, particularly in hospitals with lower surgical volumes [3]; more than double the risk of permanent vocal cord paralysis [4,5]; progression risks associated with active surveillance (AS), along with significant physical and psychological burdens compared to the general population [6]; and radioactive iodine therapy (RAI) induced side effects, such as bone marrow suppression and salivary gland damage, with sialadenitis occurring in over 20% of cases [7,8].\u003c/p\u003e\u003cp\u003eThe emergence of ultrasound-guided thermal ablation (TA) offers a minimally invasive solution for recurrent LNM. TA induces coagulative necrosis in tumors via thermal effects (60–100°C) and enables precise targeting under high-resolution ultrasound guidance, with established efficacy in thyroid tumors [9]. However, studies on TA for recurrent thyroid cancer, especially in low-burden lymph node metastasis, are limited, and comparative analyses with conventional surgery remain scarce. This study aims to conduct a dual-center retrospective cohort analysis to systematically evaluate differences between TA and neck dissection in tumor control, safety, quality of life, and socioeconomic outcomes, providing evidence-based guidance for stratified treatment of recurrent thyroid cancer.\u003c/p\u003e"},{"header":"Methods","content":"\u003ch2\u003e1.1 Study Design\u003c/h2\u003e\u003cp\u003e This study was a dual-center retrospective cohort study, conducted in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Ethical approval was obtained from the Institutional Review Board [Approval No.: MTCA, ECFAH of FMU (2015) 084 − 2], with waiver of informed consent.\u003c/p\u003e\u003ch2\u003e1.2 Participants\u003c/h2\u003e\u003ch2\u003e1.2.1 Patient Selection\u003c/h2\u003e\u003cp\u003eA total of 512 patients with recurrent thyroid cancer presenting with lymph node metastasis, treated at two centers between January 2016 and April 2022, were screened. The final analysis included 230 patients: 115 in the thermal ablation group (TAG) and 115 in the reoperation group (RSG) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003ch2\u003e1.2.2 Inclusion and Exclusion Criteria\u003c/h2\u003e\u003cp\u003eInclusion Criteria\u003c/p\u003e\u003cp\u003e① Diagnosis confirmed by fine needle aspiration cytopathology or surgical histology as PTC with cervical lymph node metastasis;\u003c/p\u003e\u003cp\u003e② ≤3 metastatic lesions, with the largest lesion \u0026lt; 2 cm in diameter;\u003c/p\u003e\u003cp\u003e③ Completion of standardized 36-month follow-up, including psychological assessment at postoperative month 1, with complete clinical and data records.\u003c/p\u003e\u003cp\u003eExclusion Criteria\u003c/p\u003e\u003cp\u003e① Patients receiving palliative treatment;\u003c/p\u003e\u003cp\u003e② History of prior cervical radiotherapy;\u003c/p\u003e\u003cp\u003e③ Concurrent diagnosis of other malignancies.\u003c/p\u003e\u003ch2\u003e1.2.3 Follow-Up Principles\u003c/h2\u003e\u003cp\u003eThe total follow-up period was 36 months, with scheduled follow-ups at postoperative months 1, 3, 6, 9, 12, 18, 24, 30, and 36. Follow-ups were conducted via in-person clinical visits. A psychological assessment was performed at the first postoperative month. At each follow-up visit, ultrasound examinations and serum thyroglobulin (Tg) tests were conducted. For the thermal ablation group (TAG), target lymph nodes were measured using preoperative imaging as the dimensional reference, including three-dimensional diameters. Clear images were retained to calculate the volume reduction ratio (VRR): \u003cb\u003eVRR (%) = (Initial Volume − Final Volume) / Initial Volume × 100%\u003c/b\u003e.\u003c/p\u003e\u003cp\u003eTwo imaging experts, blinded to group allocation, independently evaluated the quality of follow-up imaging. Consensus-based standardized measurements were performed for disputed imaging data. For the ablation group, at least one contrast-enhanced ultrasound examination was included in the 36-month follow-up.\u003c/p\u003e\u003ch2\u003e1.3 Interventions\u003c/h2\u003e\u003ch2\u003e1.3.1 RSG (n = 115)\u003c/h2\u003e\u003cp\u003eAll enrolled patients underwent lymph node dissection based on the nodal classification of the 8th edition of the AJCC. Central compartment dissection included levels VI + VII (inferior boundary: innominate artery); lateral neck dissection included levels IIa, III, IV, and Vb (with preservation of the accessory nerve). Intraoperative neuromonitoring (IONM) followed the guidelines of the International Neuromonitoring Study Group (INMSG) to protect the recurrent laryngeal nerve. En bloc resection was performed to ensure negative margins, and functional neck dissection preserved non-lymphatic structures.\u003c/p\u003e\u003ch2\u003e1.3.2 TAG (n = 115)\u003c/h2\u003e\u003cp\u003eAll procedures were performed by interventional physicians with \u0026gt; 5 years of experience (annual surgical volume ≥ 50 cases). Preoperatively, patients and their families were thoroughly informed about the surgical approach, process, and details, and received comforting psychological counseling to minimize anxiety. Patients underwent training for respiratory control, swallowing suppression, and cough management during airway stimulation.\u003c/p\u003e\u003cp\u003eProcedures were conducted under local anesthesia, ensuring patient consciousness. Sedation was administered only when cooperation difficulties arose. Continuous electrocardiogram monitoring was maintained throughout. Microwave ablation (MWA) was performed under high-resolution ultrasound guidance. A ≥ 5 mm fluid isolation zone (using saline or 5% glucose) was created around the ablation target to protect adjacent tissues. To prevent absorption of the isolation fluid during prolonged procedures, supplemental bolus injections or continuous infusion under pressure were administered.\u003c/p\u003e\u003cp\u003eOperation mode and energy parameters: Fixed-position ablation was prioritized. For larger targets, multiple fixed-position ablations followed a \"distal-to-proximal, deep-to-superficial\" principle. Single-point energy settings: Central compartment: 25–30 W × 90 seconds; Lateral neck: 30–35 W × 60 seconds.\u003c/p\u003e\u003cp\u003eReal-time two-dimensional imaging monitored ablation boundaries. Post-procedure, multimodal ultrasound imaging (contrast-enhanced ultrasound and elastography) assessed ablation completeness. Residual areas underwent immediate supplemental ablation until therapeutic standards were met (Figure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows a complete ablation case).\u003c/p\u003e\u003ch2\u003e1.3.3 Special Management Guidelines\u003c/h2\u003e\u003cp\u003eAll patients with BRAF mutation were administered TSH suppressive therapy (target TSH level: \u0026lt;0.1 mU/L).\u003c/p\u003e\u003ch2\u003e1.4 Outcomes\u003c/h2\u003e\u003cp\u003ePrimary Outcomes: Disease progression, defined as:\u003c/p\u003e\u003cp\u003e(1) Confirmed cervical recurrent tumor via FNA or histology;\u003c/p\u003e\u003cp\u003e(2) Distant metastasis.\u003c/p\u003e\u003cp\u003eThe recurrence-free survival (RFS) was calculated from the date of surgery to the time of disease progression or the last follow-up visit.\u003c/p\u003e\u003cp\u003eSecondary Outcomes Included:\u003c/p\u003e\u003cp\u003e(1) Surgical time and intraoperative blood loss;\u003c/p\u003e\u003cp\u003e(2) Postoperative complications;\u003c/p\u003e\u003cp\u003e(3) Changes in postoperative thyroglobulin (Tg);\u003c/p\u003e\u003cp\u003e(4) Volume reduction ratio (VRR) of ablated lymph nodes;\u003c/p\u003e\u003cp\u003e(5) Hospitalization costs and length of stay;\u003c/p\u003e\u003cp\u003e(6) Psychological assessment results at 1 month post-surgery.\u003c/p\u003e\u003ch2\u003e1.5 Statistical Analysis\u003c/h2\u003e\u003ch2\u003e1.5.1 Dataset Processing\u003c/h2\u003e\u003cp\u003e\u003cem\u003ePropensity score matching\u003c/em\u003e was performed to control for confounding bias, with 1:1 matching based on age (± 3 years), sex, and tumor size (± 0.2 cm), using a caliper of 0.02. Post-matching balance assessment of covariates was conducted using standardized mean differences (SMD \u0026lt; 0.1).\u003c/p\u003e\u003ch2\u003e1.5.2 Statistical Testing Methods\u003c/h2\u003e\u003cp\u003eContinuous variables, confirmed as non-normally distributed via the Shapiro-Wilk test, were described as median (interquartile range, IQR). Group comparisons used the Wilcoxon rank-sum test, reporting Hodges-Lehmann median difference estimates and their 95% confidence intervals (CI). Effect size was quantified using \u003cem\u003eCliff’s delta\u003c/em\u003e (|δ| ≥ 0.66 indicated a large effect). Categorical variables were described as frequency (percentage), with group comparisons analyzed by Fisher’s exact test. Relative risks (RR) and their 95% CIs were calculated. Bonferroni correction was applied for multiple comparisons, with adjusted \u003cem\u003ep\u003c/em\u003e-values \u0026gt; 0.05 considered statistically non-significant. All analyses were performed using R version 4.5.0, with a significance level of α = 0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Baseline Characteristics\u003c/h2\u003e\u003cp\u003eAfter propensity score matching, baseline characteristics were balanced between the two groups, with all variables showing SMD\u0026thinsp;\u0026lt;\u0026thinsp;0.1 (the largest SMD in this study was 0.092), indicating successful matching and good comparability. Subsequent efficacy analysis could be conducted (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\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\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\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=\"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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e\u003cp\u003eTable of Baseline Characteristics Comparison After Propensity Score Matching (Including Standardized Differences)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eTAG Group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;115)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eRSG Group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;115)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eSMD\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\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\u003e\u003cb\u003eAge (years)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e43.8\u0026thinsp;\u0026plusmn;\u0026thinsp;14.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e42.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.527\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eFemale sex\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e63 (54.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e60 (52.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.052\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.692\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eLymph node compartment\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.041\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.831\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Central (CNC)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e34 (29.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e33 (28.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; Lateral (LNC)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61 (53.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e64 (55.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u0026bull; CNC\u0026thinsp;+\u0026thinsp;LNC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e20 (17.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e18 (15.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eNo. of MLNs\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.092\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.023\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eMax diameter (cm)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.42\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.003\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.935\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eBRAF V600E positive\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e82 (71.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e79 (68.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.056\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.668\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003eTg level (ng/mL)\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e12.4\u0026thinsp;\u0026plusmn;\u0026thinsp;18.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10.2\u0026thinsp;\u0026plusmn;\u0026thinsp;16.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.084\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.312\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cb\u003ePropensity score\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.074\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.285\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Comparison of Cumulative Recurrence Rates within 36 Months\u003c/h2\u003e\u003cp\u003eBased on 36-month follow-up data, 7 cases of disease progression were observed in the RSG group, while the TAG group reported 5 cases. The characteristics of patients with recurrence in both groups are detailed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. There was no significant difference in relapse-free survival rates between the RSG and TAG groups (Log-rank \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.54; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"578\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 578px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 2. Table of Summary of Characteristics of Recurrence Patients\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eRSG (N=7)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTAG (N=5)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMean (SD)\u0026nbsp;\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e47.7 (11.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e45.6 (12.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMedian [Min, Max]\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e[32.0,64.0]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e46.0 44.0 [31.0, 64.0]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMale\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1 (14.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e3 (60.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eFemale\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e6 (85.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e2 (40.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCompartment\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eCNC\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e2 (28.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1 (20.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eLNC\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e4 (57.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e4 (80.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eBoth\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1 (14.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eNum_MLNs\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMean (SD)\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.71 (0.951)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.00 (0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMedian [Min, Max]\u0026nbsp;\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.00 [1.00, 3.00]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.00 [1.00, 1.00]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMax Diameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMean (SD)\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.09 (0.170)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.41(0.365)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMedian [Min, Max]\u0026nbsp;\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.06 [0.900, 1.40]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.22 [1.10, 1.98]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBRAF V600E\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eNegative\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1 (14.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003ePositive\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e6 (85.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e5(100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTg\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMean (SD)\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e4.87 (8.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e13.5 (13.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cul\u003e\n \u003cli\u003eMedian [Min, Max]\u0026nbsp;\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e1.85 [0.0400,23.1]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 193px;\"\u003e\n \u003cp\u003e7.57 [0.0400, 33.4]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\u003cp\u003eThe cumulative recurrence rates were 6.0% (n\u0026thinsp;=\u0026thinsp;7/115) for the RSG group and 4.3% (n\u0026thinsp;=\u0026thinsp;5/115) for the TAG group, with an absolute difference of 1.7% between the groups (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u0026thinsp;\u0026minus;\u0026thinsp;1). The relative risk (RR) was 1.39 (95% CI: 0.45\u0026ndash;4.33) (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u0026thinsp;\u0026minus;\u0026thinsp;2), and the \u003cem\u003ep\u003c/em\u003e-value was 0.56. After Bonferroni correction, the \u003cem\u003ep\u003c/em\u003e-value remained 1.00, indicating no statistically significant difference in recurrence rates between the two groups.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Comparison of Surgery Time and Intraoperative Blood Loss between the RSG and TAG Groups\u003c/h2\u003e\u003cp\u003eThe surgery time in the RSG group was significantly longer than that in the TAG group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with an extremely large effect size (\u003cem\u003eδ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.94, 95% CI: 0.88\u0026ndash;0.97; Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003eA). For intraoperative blood loss, the RSG group exhibited significantly higher volumes compared to the TAG group (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), with a large effect size (\u003cem\u003eδ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.90, 95% CI: 0.85\u0026ndash;0.94; Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003eB).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Postoperative Major Complications\u003c/h2\u003e\u003cp\u003eThe primary postoperative complications analyzed in this study included transient/permanent recurrent laryngeal nerve injury, transient/permanent hypocalcemia, postoperative hematoma, and infection. The incidence of complications in each group is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e6\u003c/span\u003e. Specifically:\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eTransient recurrent laryngeal nerve injury was more frequent in the TAG group (5.2% vs. 2.6%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.42);\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eInfection occurred exclusively in the RSG group (1.7% vs. 0%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.50);\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePostoperative hematoma was more common in the RSG group (2.6% vs. 0.9%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.44);\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003ePermanent hypocalcemia was observed only in the RSG group (0.9% vs. 0%, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.00).\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eAfter Bonferroni correction, no statistically significant differences in complication rates were found between the two groups (corrected \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026gt;\u0026thinsp;0.7).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\u003ch2\u003e2.5 Calculation of Volume Reduction Ratio (VRR)\u003c/h2\u003e\u003cp\u003eAt the 36-month follow-up, the average VRR of the targeted lymph nodes reached 94.0% (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003e), and no viable tissue was observed in the target lymph nodes during final contrast-enhanced imaging. Among these, the proportion of patients with VRR reaching 100% increased to 2.59% at approximately 18 months, rose significantly to 15.52% at 24 months, and ultimately reached 47.41% by 36 months post-surgery (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec21\" class=\"Section2\"\u003e\u003ch2\u003e2.6 Changes in Tg between the RSG and TAG Groups\u003c/h2\u003e\u003cp\u003eOverall Trend Analysis (Figs.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e9\u003c/span\u003e\u0026thinsp;\u0026minus;\u0026thinsp;1 and 9\u0026thinsp;\u0026minus;\u0026thinsp;2):\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eRSG group (orange): Tg levels significantly decreased in the early postoperative period (0\u0026ndash;3 months) and stabilized after 6 months, maintaining a median value below 1 ng/mL. The trajectory followed a \"rapid decline \u0026rarr; stable maintenance\" pattern.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eTAG group (blue): Tg levels decreased more gradually, with higher values still observed at 3 months postoperatively. The median approached 1 ng/mL only after 12 months, exhibiting a \"gradual decline\" pattern.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eThe RSG group achieved and maintained low Tg levels (\u0026lt;\u0026thinsp;1 ng/mL) faster than the TAG group; however, the RSG group had inherently lower baseline Tg levels, which may introduce bias into the results. Both groups maintained stable Tg levels during the 18\u0026ndash;36-month postoperative period, but the RSG group retained significantly lower median values (\u0026lt;\u0026thinsp;0.04 ng/mL), while the TAG group remained above 0.2 ng/mL.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec22\" class=\"Section2\"\u003e\u003ch2\u003e2.7 Quality of Life\u003c/h2\u003e\u003cp\u003eAt 1 month postoperatively, the EORTC QLQ-C30 score in the TAG group was significantly higher than that in the RSG group [82.8\u0026thinsp;\u0026plusmn;\u0026thinsp;5.5 vs. 73.1\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8; mean difference\u0026thinsp;=\u0026thinsp;9.7, 95% CI: 7.9\u0026ndash;11.5; \u003cem\u003et\u003c/em\u003e(205.6)\u0026thinsp;=\u0026thinsp;11.42, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001, Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.42] (Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec23\" class=\"Section2\"\u003e\u003ch2\u003e2.8 Health Economics\u003c/h2\u003e\u003cp\u003eThe hospital stay in the TAG group was significantly shorter than that in the RSG group (Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e11\u003c/span\u003e), with a mean difference of 7.2 days (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Notably, 91.3% of patients in the TAG group had a hospital stay of only 1 day.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eRegarding hospitalization costs, the RSG group incurred an average cost of 22,867 RMB (median: 17,534 RMB). In contrast, the local health insurance reimbursement system for the TAG group used a Diagnosis-Related Group (DRG) payment model with a capped fee of 12,000 RMB. Consequently, hospitalization costs in the TAG group were significantly lower than those in the RSG group.\u003c/p\u003e\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eLow burden lymph node metastasis is an important concept in the clinical management of thyroid cancer, particularly papillary thyroid carcinoma (PTC), typically referring to cases with a small number of metastatic lymph nodes (\u0026le;\u0026thinsp;3) or minute metastatic foci [10,11]. The ATA (American Thyroid Association) guidelines suggest that for low-burden lymph nodes\u0026mdash;especially those with a maximum diameter\u0026thinsp;\u0026le;\u0026thinsp;8 mm and annual growth rate\u0026thinsp;\u0026lt;\u0026thinsp;3\u0026ndash;5 mm/year\u0026mdash;active surveillance can be adopted if there is no proximity to or invasion of critical structures such as the recurrent laryngeal nerve or trachea. However, in real-world practice, this approach may cause significant psychological burden for patients, potentially leading to somatic symptoms like fatigue. A three-year survey of 2,454 patients with differentiated thyroid cancer (DTC) reported a 4.1% recurrence rate among treated individuals. Although psychological well-being scores among relapsed patients showed only minor differences compared to those with persistent thyroid cancer lesions, both groups exhibited significantly lower mental health levels than the general population [12].\u003c/p\u003e\u003cp\u003eAdjuvant radioactive iodine therapy (RAI) has been shown in prior retrospective studies [13\u0026ndash;15] and a recent randomized trial [16] to not reduce recurrence rates in low-risk thyroid cancer patients during 3-year follow-up. In a randomized controlled trial involving 750 patients [16], the recurrence rate was 4.1% in the RAI-treated group versus 4.4% in the non-RAI group (difference: -0.3 [90% CI, -2.7 to 2.2]). This observation may be attributed to intrinsic radioiodine resistance in a subset of patients, raising doubts about the reliability of RAI in recurrent cancer treatment. Additionally, RAI carries risks of secondary hematologic malignancies and salivary gland dysfunction, which could adversely impact patients' quality of life.\u003c/p\u003e\u003cp\u003eUltrasound-guided thermal ablation is an effective treatment modality for solid tumors, achieving surgical-equivalent local control through instant high-temperature induction of protein denaturation, nucleic acid destruction, and microvascular embolization in tumor cells. Standardized operational protocols have been well established for its application in thyroid neoplasms and cervical lymph node metastasis, particularly in East Asia where thermal ablation techniques were pioneered and widely adopted, with relevant expert consensuses already published [17\u0026ndash;19]. However, evidence regarding its therapeutic role in recurrent thyroid cancer with low-burden lymph node metastasis, as well as comparative studies with repeat surgery, remains relatively scarce. Our research findings provide compelling evidence to address this knowledge gap. The microwave ablation (MWA) procedure employed in this study represents a prevalent thermal ablation technology, characterized by high thermal efficiency, excellent thermal field conformality, and a short active tip of the microwave antenna, making it particularly well-suited for small tumor applications.\u003c/p\u003e\u003cp\u003eThe results of this study indicate that there was no significant difference in the cumulative recurrence rate within 36 months between the thermal ablation group and the reoperation group (p\u0026thinsp;=\u0026thinsp;0.56, p\u0026thinsp;=\u0026thinsp;1.00 after Bonferroni correction), demonstrating that thermal ablation is as effective as reoperation in controlling recurrent lesions. Although no statistically significant difference in cumulative recurrence rate was observed between the groups in this study, we found that the cumulative recurrence proportion in the reoperation group was higher than that in the thermal ablation group. This difference may be attributed to: (1) Incomplete resection of lesions, increased bleeding during the second operation, and limited visual field caused by scars from previous surgeries, leading to incomplete resection of lesions [20]; (2) Increased bleeding and the greater trauma associated with open surgery enhance the opportunity for tumor dissemination. Thermal ablation is performed under high-resolution ultrasound guidance, allowing real-time monitoring of the ablation process and immediate post-procedure assessment of the ablation area. Moreover, due to its minimally invasive nature and the thermal field covering the needle track, thermal ablation minimizes the risks of incomplete tumor destruction and needle track seeding.\u003c/p\u003e\u003cp\u003eIn this study, thermal ablation demonstrated superior performance compared to the reoperation group in terms of operative duration and intraoperative blood loss control. This advantage arises from severe inter-tissue adhesion in reoperation patients, where surgical procedures rely on visual identification by surgeons. The blurred structural demarcation of tissue layers increases operative difficulty, leading to prolonged surgical time and heightened risk of vascular injury during dissection [20,21]. Regarding postoperative complication rates\u0026mdash;including transient recurrent laryngeal nerve injury, permanent recurrent laryngeal nerve injury, transient hypocalcemia, permanent hypocalcemia, postoperative hematoma, and infection\u0026mdash;no statistically significant differences were observed between the thermal ablation group (TAG) and reoperation group (RSG). During open surgery, neurological structure differentiation and dissection become challenging due to tissue adhesion [20,21]; however, real-time intraoperative neural monitoring effectively mitigates nerve injury risks [22,23]. Although thermal ablation lacks a neural monitoring system akin to open surgery, high-resolution ultrasound assistance facilitates neural tissue differentiation [24,25]. Additionally, the hydrodissection technique employs injection pressure to precisely dissect adherent tissues and establishes a liquid barrier between the ablation target and critical structures, isolating thermal conduction and ensuring peripheral tissue safety [26]. Despite no statistical difference in recurrent laryngeal nerve injury incidence between groups, TAG exhibited a higher absolute count of transient injuries, primarily manifesting as low-pitched voice hoarseness without dysphagia or respiratory compromise, indicative of unilateral nerve involvement [27]. These cases typically resolved by the day following surgery, potentially attributable to local anesthetic infiltration or rapid tissue absorption of hydrodissection fluid without timely replenishment, causing minor thermal energy-induced damage [28]. Only one case of permanent hypocalcemia occurred in the RGS group, resulting from unintentional parathyroidectomy during central compartment lymph node dissection. To ensure maximal margin safety, excessive redundant tissue removal based on visual inspection led to parathyroid misadventure [29]. While misremoved parathyroids can undergo heterotopic transplantation, survival cannot be guaranteed [30], a risk further compounded in reoperation settings due to increased anatomical complexity, elevating parathyroid damage and permanent hypocalcemia risks [31]. The RSG group also showed higher absolute numbers of infection and postoperative hematoma cases, likely due to greater surgical trauma and prolonged operative times associated with open surgery [32,33].\u003c/p\u003e\u003cp\u003eAfter thermal ablation, the ablated target lymph nodes gradually shrink over time, eventually disappearing completely or undergoing fibrous scarring. A meta-analysis [34] investigated the mean volume reduction rate (VRR) of lymph nodes after thermal ablation, revealing that the average VRR ranged from 77.9\u0026ndash;99.4%, with variations dependent on the ablation modality, among which microwave ablation achieved the highest VRR. The VRR of target lymph nodes in this study fell within the range reported in previous research, at 36 months post-ablation, the mean VRR of target lymph nodes reached 94.0%, and contrast-enhanced imaging confirmed the absence of metabolic activity in all lymph nodes. Additionally, in our cohort, the proportion of patients with a VRR of 100% increased to 2.59% at approximately 18 months, rose significantly to 15.52% by 24 months, and further ascended to 47.41% by 36 months post-ablation. This indicates that significant changes manifest around 24 months post-treatment, suggesting that complete resolution of lesions is challenging to achieve in the early post-treatment period. The discrepancies in VRR values across studies likely stem not only from differences in ablation techniques but also from variability in boundary delineation of target structures and measurement dimensions among examiners. Our team recommends retaining preoperative imaging as a reference standard, using surrounding anatomical landmarks as anchors for image fusion to ensure consistent measurement planes in follow-up assessments. Furthermore, standardizing follow-up personnel and equipment can minimize systematic errors. While VRR is a straightforward, non-invasive metric effective for routine evaluation, contrast-enhanced imaging [35] for assessing lymph node viability carries greater diagnostic weight in follow-up, as it provides functional evaluation at the molecular imaging level.\u003c/p\u003e\u003cp\u003eRegarding Tg level control, based on preoperative and 36-month postoperative follow-up observations, the RSG group demonstrated a more rapid and consistent biochemical remission advantage, particularly with significant differences during the critical postoperative period (3\u0026ndash;12 months). This aligns with conclusions from previous related studies [36,37]; however, due to the lower baseline Tg levels in the RSG group in this study, there may be a bias in evaluating early control efficiency. Regarding long-term outcomes, both groups maintained stable states in the long term (\u0026gt;\u0026thinsp;18 months). Additionally, the higher proportion of persistently detectable Tg values (\u0026gt;\u0026thinsp;1 ng/mL) in the TAG group suggests that closer follow-up or adjuvant therapy may be required.\u003c/p\u003e\u003cp\u003eRegarding patients' quality of life, thermal ablation therapy demonstrated advantages due to its rapid treatment process, absence of postoperative incision care requirements, shorter recovery time, and improved patient comfort and experience [38,39]. In this study, the significantly higher quality-of-life scores (EORTC QLQ-C30) observed in the TAG group at 1 month post-surgery clearly demonstrate this advantage compared to the reoperation group.\u003c/p\u003e\u003cp\u003eNotably, the reoperation group and thermal ablation group exhibited significant differences in hospital stay duration, hospitalization costs, and overall public healthcare resource utilization. In this study, the thermal ablation group's average hospital stay and hospitalization costs were substantially lower than those of the reoperation group. While hospitalization costs may vary across regions due to policy differences, the marked reduction in hospital stay days in the ablation group significantly reduced public resource consumption and enhanced workforce efficiency maintenance.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eLimitations of the Study\u003c/strong\u003e\u003cp\u003eThis study was retrospective with a relatively small sample size (n\u0026thinsp;=\u0026thinsp;115 per group), which may have resulted in insufficient statistical power. Future studies with larger sample sizes are warranted to confirm these trends. Previous literature has reported that the peak recurrence period for papillary thyroid carcinoma may extend beyond 36 months [40,41,42] (due to limited research on re-recurrence after treated recurrence, only primary recurrence data were referenced here). The current study may have underestimated the probability of re-recurrence, and longer-term follow-up studies are anticipated to address this gap.\u003c/p\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe results of this study confirm that in postoperative patients with recurrent low-burden lymph node metastasis of papillary thyroid carcinoma, thermal ablation can serve as a viable alternative to surgery due to its non-inferior oncological outcomes, comparable complication rates, shorter operative time, reduced intraoperative blood loss, superior short-term quality-of-life scores, and higher efficiency in workforce maintenance. However, its value extends beyond introducing a novel technique; it represents a paradigm shift in thyroid cancer treatment\u0026mdash;transitioning from \"maximum tolerated therapy\" to \"minimum effective intervention.\" Future prospective randomized controlled trials (RCTs) across multiple centers with larger cohorts are required to validate long-term efficacy. The ultimate goal is to provide personalized precision treatment options for patients stratified by risk, achieving the optimal balance between radical tumor control and quality of life.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approvaland consent to participate:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Ethics Committee\u0026nbsp;of First Affiliated Hospital of Fujian Medical University (Approval Number: MTCA, ECFAH of FMU [2015] 084-2) and granted an exemption from informed consent. All research procedures complied with the Declaration of Helsinki principles. We implemented rigorous measures to protect participants' privacy and data security, including complete anonymization of personal information to prevent identification. All research personnel had undergone ethics training. We hereby affirm our commitment to upholding the highest ethical standards throughout study conduct and reporting, thereby ensuring scientific rigor, equity, and ethical integrity.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003cstrong\u003e：\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are not publicly available due the funding agency's internal requirements for data management but are available from the corresponding author on reasonable request. Any requests for data must specify the required information in detail and state the purpose for which the data will be used.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was supported by the following fund:\u003c/p\u003e\n\u003cp\u003eProvincial subsidy fund for health and wellness from Fujian Provincial Department of Finance (Grant number: BPB-2022YXJ).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSongsong Wu was responsible for the experimental design; Xiaojian Ye and Yan lei were responsible for data analysis and manuscript drafting; Jinshu zeng and Jianchuan Yang were responsible for data quality control; Lingpeng Tang, Xiaoying Lin, Xueqing Lin, Qi Zhong ang Yuqi Hong were responsible for data collection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number:\u0026nbsp;\u003c/strong\u003enot applicable.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBoucai, L., Zafereo, M., \u0026amp; Cabanillas, M. 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Cancer medicine, 12(12), 13270\u0026ndash;13278. https://doi.org/10.1002/cam4.6018\u003c/li\u003e\n\u003cli\u003eAttia, A., Touma, E., Lussey-Lepoutre, C., Ghander, C., Jouinot, A., Roy, M., Housni, S., Chereau, N., Menegaux, F., Leenhardt, L., \u0026amp; Buffet, C. (2024). Consideration of Early Dynamic Risk Stratification to Guide Discharge from Oncologic Follow-Up in Patients with Differentiated Thyroid Cancer. Thyroid : official journal of the American Thyroid Association, 34(12), 1465\u0026ndash;1475. https://doi.org/10.1089/thy.2024.0119\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"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":"Thermal Ablation, Neck Dissection, Recurrent Papillary Thyroid Carcinoma, Lymph Node Metastasis, Low-Burden Lymph Nodes, Quality of Life","lastPublishedDoi":"10.21203/rs.3.rs-7272514/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7272514/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eObjective:\u003c/strong\u003e To compare ultrasound-guided thermal ablation (TA) with conventional neck dissection (CND) for recurrent low-burden lymph node metastasis (≤3 lesions, \u0026lt;2 cm) in thyroid cancer, aiming to guide precision therapy.\u003cbr\u003e\n \u003cstrong\u003eMethods: \u003c/strong\u003eA dual-center retrospective study (2016–2022) analyzed 230 patients with recurrent lymph node metastasis, stratified into TA (\u003cem\u003en\u003c/em\u003e = 115) and reoperation groups (\u003cem\u003en\u003c/em\u003e = 115). Endpoints included recurrence-free survival, complications, thyroglobulin (Tg) dynamics, quality of life (EORTC QLQ-C30), and healthcare costs.\u003cbr\u003e\n \u003cstrong\u003eResults:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eOncological Outcomes: No significant \u0026nbsp;difference in 36-month recurrence rates (Log-rank \u003cem\u003ep\u003c/em\u003e = \u0026nbsp;0.54; Bonferroni-corrected \u003cem\u003ep\u003c/em\u003e = 1.00).\u003c/li\u003e\n \u003cli\u003eSafety: Similar complication rates (nerve injury, hypocalcemia, hematoma, infection; all \u003cem\u003ep\u003c/em\u003e \u0026gt; 0.7).\u003c/li\u003e\n \u003cli\u003eTA Advantages: Shorter operative \u0026nbsp;time, less blood loss, faster recovery, shorter hospital stays, and lower costs. 50% of TA-treated patients achieved complete lymph node volume reduction (100% VRR) within 36 months.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e TA demonstrates non-inferior oncological efficacy to CND for strictly selected patients with recurrent low-burden lymph node metastasis, offering minimally invasive precision therapy with superior procedural efficiency and quality-of-life benefits.\u003c/p\u003e","manuscriptTitle":"Thermal Ablation vs. Conventional Neck Dissection for Recurrent Low-Burden Lymph Node Metastasis in Thyroid Cancer: A Dual-Center Retrospective Cohort Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-17 11:05:15","doi":"10.21203/rs.3.rs-7272514/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":"8d25a873-6ca1-443e-9b1d-9ad836a97f57","owner":[],"postedDate":"September 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":54735463,"name":"Biological sciences/Cancer"},{"id":54735464,"name":"Health sciences/Oncology"}],"tags":[],"updatedAt":"2025-10-16T05:38:54+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-17 11:05:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7272514","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7272514","identity":"rs-7272514","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}