Efficacy and Safety of Ultrasound Guided Microwave versus Radiofrequency Ablation of Benign Thyroid Nodules

Efficacy and Safety of Ultrasound Guided Microwave versus Radiofrequency Ablation of Benign Thyroid Nodules | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Efficacy and Safety of Ultrasound Guided Microwave versus Radiofrequency Ablation of Benign Thyroid Nodules Nouran Elghitany, Osama Hetta, Mohamed Gamaleldin, Asaad Sorial This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5383714/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 18 Jun, 2025 Read the published version in Egyptian Journal of Radiology and Nuclear Medicine → Version 1 posted You are reading this latest preprint version Abstract Background: to compare the two ablation techniques, we assessed 81 benign thyroid nodules of 38 cases who underwent radiofrequency ablation (RFA) and 43 cases who underwent microwave ablation (MWA) over a 12-month period. The inclusion criteria involved benign thyroid nodules with compression symptoms or cosmetic problems, cytological confirmation of benignity with no atypical cells, and case refusal or unfit for operation. No predilection for the ultrasound nature of the nodules, whether they were cystic, solid, or complex, or their size or number. radiofrequency ablation was carried out utilizing the Mygen (M-3004) radiofrequency generator from radiofrequency Medical Co., Ltd., South Korea, and MWA (Microwave Ablation) was conducted utilizing the Canyon KY2000-A MCW generator from Canyon Medical Inc. The clinical problems and the nodules volume have been assessed both following and prior to the surgery. Factors and complications associated with Volume Reduction Rate (VRR) have been assessed. This investigation is designed to evaluate the efficacy and safety of microwave ablation guided by ultrasound (US) versus radiofrequency ablation in the management of benign thyroid nodules. Results Mean VRR(volume reduction rate) of MWA group versus the RFA group at one, three, six, and twelve months were 53.1% ± 11.2% vs. 45.8% ± 13.5% (P =0.009), 67.9% ± 11.5%vs. 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7%vs. 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% vs. 83.6% ± 6.4% (P-value = 0.252), respectively. A statistically significant variance has been discovered within the VRR among both the radiofrequency ablation group and the microwave ablation group in one and three month follow up. Additionally, all cases were able to maintain thyroid function, and both groups reported a significant reduction in symptom and cosmetic scores. Among the overall case population, one patient in the RF group had a minor burn that resolved after 1 month and transient voice changes occurred in one patient in each group that resolved after two weeks. Conclusions: Both radiofrequency ablation and microwave ablation are safe and efficient methods for managing BTNs. The MWA group showed greater volume reduction rates at the 1- and 3-month follow-ups. Microwave ablation radiofrequency ablation volume reduction rate benign thyroid nodules Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 INTRODUCTION Within the past two decades, the widespread application of radiological imaging has resulted in the increased detection of incidental finding of benign thyroid nodules in approximately half of the general population through ultrasound assessment, which is one of the most common lesions in clinical practice. [ 1 ] Benign thyroid nodules are usually asymptomatic. However, some nodules cause compression symptoms, cosmetic or psychological problems. In these cases, interventions including surgical and nonsurgical procedures will be recommended. [ 2 ] Despite the fact that surgery is an effective measure for the management of thyroid nodules, it has a risk of 2–10% to cause hypothyroidism and neck scarring. Other listed complications are bleeding, hypocalcemia, permanent recurrent laryngeal nerve palsy, hypocalcemia and postoperative infections. [ 3 ] Another traditional therapeutic technique is radioiodine treatment, which additionally carries the risk of after-management nausea, hypothyroidism, and need for isolation. For these reasons, a several cases with thyroid nodules seek for alternative therapy techniques, including percutaneous thermal ablation, which is minimally invasive and doesn’t need radioactive substances or general anesthesia. [ 4 ] Radiofrequency ablation and microwave ablation are the most frequently utilized percutaneous thermal ablation methods for thyroid tissue. The basic principle of both approaches is to induce thermal damage by heating the tissue to induce thermal coagulative necrosis of the tissue around the needle tip [ 5 ] RFA was first introduced in 2006 which since then was stated to be both effective and safe for managing benign thyroid nodules by generating friction and conductive heat using high- frequency alternating electric current oscillating between 200 and 1200 kilohertz. The tissue immediately adjacent to the electrode point is affected by the frictional heat, whereas the conduction heat from the ablation area spreads more insidiously to the surrounding tissues, resulting in additional cell necrosis. Internally cooled RF electrodes, featuring hollow lumens for continuous internal cooling, improve coagulation by reducing tissue heating near the electrode. This cooling effect minimizes tissue charring and impedance rises, enabling greater current deposition [ 5 ][ 6 ]. In comparison to RFA, microwave ablation is a percutaneous thermal ablation method which utilizes nonionizing electromagnetic radiation to heat nodular tissue. It has been shown to have the following benefits: a homogeneous ablated area, a decreased heat sink impact, significantly greater intralesional temperatures and decreased procedure period. [ 1 ] The advantages of the percutaneous thermal ablation technique include the ability to reduce the size of the lesions managed, the favorable cosmetic outcomes, and the absence of significant correlated complications, which prevents cases from requiring hospitalization. The method not only completely inactivates the lesion yet additionally protects the case's normal thyroid function from any inconvenience or trouble that may result from long-term administration of levothyroxine. [ 7 ] Although percutaneous thermal ablation procedure was proven to be safe and effective in management of BTNs, there’s no organized knowledge in the medical field and society on the differences between RFA and MCA, since there are inconsistencies between how the techniques are applied among different countries. [ 8 ] The objective of this investigation was to compare the efficacy of microwave and radiofrequency ablation procedures in the management of BTNs to share our clinical experiences. MATERIALS AND METHODS This prospective research comparing RFA and MWA and the utilization of these techniques has been accepted by the Ethics Committee of Ain Shams University Hospital. All patients undergoing percutaneous thermal ablation have been essential to sign and read an informed consent before the technique. (RFA or MWA) for BTNs from January 2022 to August 2024. A total of 38 cases have been managed with RFA, while a total of 43 cases have been managed with MWA. Inclusion criteria were as follow: (a) presence of either cosmetic or compressive problems, (b) ultrasound findings suggesting a benign nodule and benign cytologic confirmation by ultrasound ‑guided fine-needle aspiration cytology (FNAC), all nodules included was confirmed by cytology to be Bethesda II, if cytology results was Bethesda I a repeat FNAC was done, if III or more Ablation was differed(c) serum concentrations of thyrotropin and thyroid hormone in the normal range, and (d) refusal to undergo operation or contraindications for operation. Exclusion criteria were as follows: (a) cytologic results indicating malignancy, (b) the abnormal function of the vocal cord on the contralateral side of the lesion, and (d) Pregnancy and breast-feeding women. Equipment Canyon KY2000-A MCW generator from Canyon Medical Inc. used for MWA treatment. Mygen (M-3004) radiofrequency generator from radiofrequency Medical Co., Ltd, South Korea used for RFA treatment. The microwave antenna was 18 G, and the RFA electrode was 18 G. Preablation assessment Before ablation, ultrasound was performed by an experienced radiologist in thyroid imaging. Thyroid tumors have been carefully assessed for their morphology, structure, components (completely cystic, completely solid, or mixed with the two components and volume. The 3 diameters of each nodule (such as, two other perpendicular diameters and the largest diameter) have been determined by US to directly determine volume of each nodule. The nodule volumes have been subsequently determined utilizing the following equation: πabc/6, where (a) represents the largest diameter and (b) and (c) represent the other two perpendicular diameters. Subsequently, US-guided FNAC, laboratory tests, and clinical states were conducted to confirm the benign nature of the nodules, transcutaneous laryngeal ultrasound was performed to evaluate the vocal fold structure and function and laboratory examinations involved thyroid function (for examples, serum thyroid-stimulating hormone [TSH], free triiodothyronine [FT3], free thyroxine [FT4], blood coagulation tests and complete blood count. Moreover, every patient was evaluated for their cosmetic scores, which were as follows: Score 1: no palpable mass; Score 2: no cosmetic problem but a palpable mass; Score 3: cosmetic problem on swallowing only; and Score 4: a readily noticeable cosmetic problem. On a visual analog scale of 10 centimeters, cases self-report their symptomatic concerns, with a score of 0 indicating that they do not suffer from any symptoms or pain and [ 9 ] corresponding to agonizing and excruciating pressure symptoms. (Fig. 1) Procedure Treatment procedures have been conducted as an outpatient procedure by an experienced radiologist in RFA and MWA. Just prior to the technique, a one dosage of anti-edematous medication (hydrocortisone sodium succinate) and an IV antibiotic (sulbactam/ampicillin) was administered to each case. The cases have been positioned in the supine position with mild hyperextended neck and administered local anesthesia via subcutaneous injection. Hydro dissection was done using a 22G spinal needle with cold 5% glucose infused into the surrounding thyroid capsule under US guidance to achieve a “liquid isolating region” and to protect the vital structures of the neck (trachea, carotid artery, recurrent laryngeal nerve and esophagus,) from thermal damage. In nodules with retrosternal extension, the ablation starts from the most cranial part of the nodule as we notice that the retrosternal portion shifts up making it safer to ablate as well as repeating hydro dissection before starting to ablate the caudal portion. If the nodule was mainly cystic, the needle for fluid aspiration and the ablation probe were inserted simultaneously and the aspiration was performed first followed by removal of the needle and starting ablation of the walls of the cyst. In isthmic nodule in addition to hydro-dissection we would also use continuous irrigation with cold saline of the skin to minimize the heating effect to the skin. Ablation of the feeding artery was not a routine part of this study. The output powers for radiofrequency ablation and microwave ablation have been set between 40-100W and 30–50 watts, respectively. The "moving-shot method" was utilized during the technique, and the antenna or electrode was moved unit-by-unit to address each nodule in a manner known as the conceptual ablation units. The whole treatment was monitored using real-time US, and the ablation has been stopped when the entire nodule was ablated, and transient hyperechoic areas were observed all through the nodule [Figure 2].in MWA after the procedure we can see that the ablated area became hypoechoic which helps in confirmation of good ablation [Figure 3]. Post ablation evaluation and data analysis All patients got out in 30 minutes of the technique, involving those that had been anesthetized but had recovered fully. Cases were advised to continue using ice packs on the puncture site for approximately one hour. All cases were prescribed oral antibiotics (Clavulanate potassium + Amoxycillin) and analgesics (Paracetamol) for a period of one week following the surgery. Clinical symptoms and signs were used to evaluate complications both during surgery and following surgery. The thyroid profile, ultrasound evaluation of the thyroid nodule, cosmetic problem, and compressive symptoms had been assessed during the monitoring at one, three, six, and twelve months. The volume reduction rates were determined using the following equation: volume reduction ratio (%) = (initial volume (milliliter) - final volume (milliliter) / initial volume (ml). This was done through ultrasound imaging. For the statistical analysis, the data gathered was reviewed, coded, tabulated, and entered a PC utilizing the Statistical Package for the Social Sciences (SPSS 27). Data was expressed, and appropriate assessment was conducted based on the type of data acquired for each of the variables. Quantitative data were presented as the mean ± standard deviation. Parameters from pre-ablation, post-ablation, and monitoring have been analyzed utilizing a paired t-test. An independent-sample t-test was conducted to compare age, nodular volume, VRR, and symptom and cosmetic scores among both groups. The gender distribution, nodule location, nodule composition, and complications were examined utilizing the Chi-square test. A P-value of less than 0.05 was defined statistically significant. RESULTS Baseline characteristics of the microwave ablation and radiofrequency ablation groups. Patients with TNs have been managed with percutaneous thermal ablation in our hospital. Cases were categorized into the RFA group (number = 38) and the MWA group (number = 43) based on the first therapy approach. The baseline characteristics of the patients enrolled in the two groups are shown in Table 1. The radiofrequency ablation group consisted of 26 females and 12 males (mean age: 42.58 ± 15.8). The microwave ablation group consisted of 32 females and 11 males (mean age: 45.77 ± 15.03). Prior to therapy, also insignificant variances among the RFA and MWA ablation groups regarding other US characteristics and clinical characteristics. Table (1) : Group RF Microwave N (%) N (%) Side Right 17 (44.74%) 15 (34.88%) Left 21 (55.26%) 25 (58.14%) Isthmus 0 (0%) 3 (6.98%) (18) Consistency Solid 24 (63.16%) 29 (67.44%) Cystic (20) 3 (7.89%) 3 (6.98%) Mixed 11 (28.95%) 11 (25.58%) Retrosternal No 30 (78.95%) 35 (81.4%) Yes 8 (21.05%) 8 (18.6%) Age 42.58 ± 15.8 45.77 ± 15.03 Sex Male 12 (31.58%) 11 (25.58%) Female 26 (68.42%) 32 (74.42%) Results after followup At 1, 3, 6, and 12 months, the mean volumes of the ablated nodule in the two groups were significantly lesser than the mean volumes before ablation. The VRRs between the radiofrequency ablation group and microwave ablation group at one, three, six, and twelve months were were 53.1% ± 11.2% vs. 45.8% ± 13.5% (P = 0.009), 67.9% ± 11.5%vs. 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7%vs. 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% vs. 83.6% ± 6.4% (P = 0.252), respectively. The mean nodular volume reduction rates showed significant difference that the microwave ablation group achieved greater VRRs compared to that of the radiofrequency ablation group at 1 and 3 months follow up by the same radiologist. Table (2) : Relation between two study groups) at different time points ` Group Test of significance RF Microwave Mean ± Standard deviations Mean ± Standard deviations p-value Sig. Reduction Rate % After 1 month 45.8% ± 13.5% 53.1% ± 11.2% 0.009 [T] S After 3 months 61.8% ± 12.8% 67.9% ± 11.5% 0.027 [T] S After 6 months 73.4% ± 11% 77.5% ± 9.7% 0.084 [T] NS After 12 months 83.6% ± 6.4% 85.4% ± 7.6% 0.252 [T] NS Repeated measures < 0.001 < 0.001 [T] Student t-test of significance. Symptom score, cosmetic score, and complications: Insignificant variance in the symptom score (compressive reduction rate) among the RFA group and the MWA group at one, three, six, and twelve months, [Figure 5]. The cosmetic score between the radiofrequency ablation group and the microwave ablation group demonstrated statistically insignificant differences at one, three, six, and twelve ‑month monitoring visits, [Fig. 6]. A significant improvement of symptom and cosmetic score was found after thermal ablation at last follow-up (P < 0.05) ( Table 3, 4). Table (3) : Relation between two study groups and difference in compressive at different time points Group Test of significance RF Microwave Mean ± Standard deviations Mean ± Standard deviations p-value Sig. Compressive Pre-ablation 5 (4–7) 5 (3–7) 0.294 [M] NS After 1 month 4 (3–4) 3 (2–4) 0.248 [M] NS After 3 months 3 (2–3) 2 (2–3) 0.178 [M] NS After 6 months 2 (1–2) 1 (1–2) 0.259 [M] NS After 12 months 0 (0–1) 0 (0–0) 0.256 [M] NS Repeated measures < 0.001 < 0.001 [M] Mann-Whitney test of significance. Table (4) : Relation between two study groups and difference in cosmetic at different time points Group Test of significance RF Microwave Mean ± Standard deviations Mean ± Standard deviations p-value Sig. Cosmetic Pre-ablation 4 (4–4) 4 (3–4) 0.074 [M] NS After 1 month 3 (2–3) 3 (2–3) 0.770 [M] NS After 3 months 2 (1–2) 2 (1–2) 0.400 [M] NS After 6 months 1 (1–2) 1 (1–2) 0.316 [M] NS After 12 months 1 (1–1) 1 (1–1) 0.225 [M] NS Repeated measures < 0.001 < 0.001 [M] Mann-Whitney test of significance. Complications were observed in 3 of the 81 patients after ablation. Two patients had Voice change occurred, one in each group. The alterations in voice have been transient and completely recovered following approximately two weeks, corresponding with the partial absorption of edema by the tissues. In addition, a single patient in the RFA group had minor skin burn and recovered totally in 1 month. Thyroid function including serum TSH, FT3 and FT4 remained stable. Infection, hemorrhage, and tracheal and esophageal injury after ablation were not observed. Hypothyroidism and autoimmune thyroid disease were not observed at follow-up. DISCUSSION Thyroid nodules are prevalent in the general people, with ultrasound being the primary imaging method for their evaluation. This technique has significantly increased the detection of such nodules [10]. Larger nodules may cause pressure-related symptoms, leading to cosmetic concerns, neck discomfort, and a diminished quality of life. So far, total or partial thyroidectomy were the main treatment options. While surgery is widely accessible and generally safe in experienced hands, complications both permanent and temporary can happen within two to ten percent of cases. Total thyroidectomy invariably results in hypothyroidism, necessitating lifelong levo-thyroxine therapy. Moreover, surgery may not be suitable for high-risk patients or may be declined by some individuals [2] . Percutaneous thermal ablation defined as a safe and effective option for symptomatic BTNs [2] . A single benign diagnosis from fine needle aspiration (FNA) is adequate when the nodule displays ultrasound characteristics strongly indicative of benignity (e.g., isoechoic spongiform or partially cystic nodules with intracystic comet tail artifacts) [11]. While percutaneous thermal ablation doesn’t provide immediate removal of thyroid nodules, it induces necrosis and gradual shrinkage of the nodules, leading to volume reduction and symptom improvement, with the effectiveness of radiofrequency ablation comparable to surgical options [12] . Research has shown variable outcomes regarding the average volume reduction of thyroid nodules and the variances in volume reduction rates between radiofrequency ablation and microwave ablation. Factors influencing these results include the operator's experience, nodule composition, energy delivered, and duration of the procedure. The aim of this study is to compare the efficacy and safety of ultrasound-guided RF ablation versus microwave ablation for treating benign thyroid nodules. In our study, 81 cases with 81 nodules underwent ultrasound-guided thermal ablation using either RFA or MWA. We compared the volume reduction rates in both groups at one, three, six, and twelve months, finding statistically significant reductions in both groups, with the MWA group showing greater volume reduction at 1 and 3 months. Literature indicates that VRR after RF ablation ranges from 50% to 88.2% between 6- and 18-months post-treatment [13] . A pooled VRR of 63% was observed at twelve months post-ablation in a meta-analysis that included 7 MWA investigations, which included 1146 participants and 1226 nodules [2] . Few studies compare MWA and RFA efficacy directly, with VRR often serving as the measure of effectiveness. Results can differ based on the monitoring duration. Korkusuz et al. [14] found higher volume reduction rates with RF at 3 months, while Vorländer et al. [7] stated insignificant differences among the methods at that time point. Cheng et al. [1] also noted no differences at 3 months, but RF showed higher VRRs between 6 and 12 months. Yue et al. [3] similarly found no differences during the12 months follow up. A recent meta-analysis found no differences at 3 and 6 months but noted that RF had a higher volume reduction rate at twelve months. These studies confirm that both techniques are effective to manage BTNs. The mean volume reduction rate of the radiofrequency ablation group compared to the microwave ablation group at the three, six, and twelve months, as well as the final monitoring, were 67.6 ± 20.3% versus 64.4 ± 43.5% (p-value = 0.143), 84.1 ± 13.5% versus 78.4 ± 48.2% (p-value = 0.016), 89.6 ± 20.0% versus 82.5 ± 49.7% (p-value = 0.035), and 91.3 ± 12.6% versus 81.1 ± 70.4% (p-value = 0.045), respectively. At the third month of monitoring, the mean nodular volume reduction rate didn't demonstrate significant variance among both groups. However, statistical significance has been observed at the sixth and following months of monitoring, and the RFA group demonstrated a greater volume reduction rate compared to the microwave ablation group. While in our study the mean VRRs of the MWA group versus the RFA group at 1, 3, 6, and 12 months were 53.1% ± 11.2% versus 45.8% ± 13.5% (P =0.009), 67.9% ± 11.5% versus 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7% versus 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% versus 83.6% ± 6.4% (P = 0.252), respectively. In our findings, the mean VRRs for the MWA and RF groups at 1, 3, 6, and 12 months were 53.1% ± 11.2% vs. 45.8% ± 13.5% (P = 0.009), 67.9% ± 11.5% vs. 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7% vs. 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% vs. 83.6% ± 6.4% (P = 0.252), respectively (figure 7 and 8) In contrast to some literature, our study indicated that the MWA technique outperformed RF according to volume reduction rate at the 1- and 3-month follow-ups. Differences in clinical outcomes may stem from the technical distinctions between RF and microwave ablation and the completion of peripheral ablation. Effective treatment requires comprehensive ablation of the entire nodule, influenced by the nodule's size, its proximity to critical structures, and its composition. MWA offers a faster temperature and larger ablation volume rise comparing with RF, making it particularly advantageous for larger nodules and reducing treatment time. Its predictable and homogeneous ablation zone may also lower the probability of injury to nearby vital structures. In studies by Korkusuz et al. [14] and Vorländer et al. [7] that utilized twenty-four to thirty-six watts of microwave power, insignificant differences within volume reduction rate were observed among microwave ablation and RF at the 3-month monitoring. Yue et al. [3] additionally found no differences after 6 months with similar power outputs. In Snomez et al.'s research, that employed 60-140 watts, no differences in VRR were noted with RF after 1 month. These findings suggest that adjusting power output during MWA can minimize carbonization and enhance nodule resorption. Within our research, using a relatively low microwave power output (40-50 W) resulted in nodule shrinkage, likely because MWA is preferred for larger nodules. Another challenge with MWA is the back-heating effect from reflected waves, particularly with a 16G needle, which can produce a 2-cm back-heating zone. We mitigated this issue by utilizing 18G antennas, resulting in an increased VRR for the MWA technique. The complex neck anatomy, with multiple critical structures like the recurrent laryngeal nerve, major vessels, and trachea, necessitates that operators possess a thorough understanding of each thermal ablation technique and expertise in cervical ultrasound anatomy to avoid severe complications [7] . Various complications associated with RF and MWA have been documented, involving hematomas, skin burns, voice changes, and infections. Guo et al. [15] conducted a meta-analysis that confirmed that MWA is as safe as RF for the treatment of benign thyroid nodules, as there were insignificant variances in minor or major complications among the two procedures [2] . He et al. conducted an additional meta-analysis of randomized controlled investigations and discovered that there was insignificant difference in the total complication rates of less-invasive management methods. The complication rates in the present investigation were minimal, consistent with the existing literature. Insignificant variances have been observed among the RFA (5.2%) and MWA (2.3%) groups. We aimed to address limitations observed in other studies, such as those noted by Cerit et al. [2] by conducting a prospective study with similar nodule characteristics, including consistency, age, and gender, along with routine and consistent patient follow-up. Additionally, since MWA is typically favored for high-volume nodules, the mean nodule volume in the microwave ablation group was higher. The relatively small sample size in each group was the primary limitation of the present research. A larger sample size could be beneficial to strengthen our conclusions. Furthermore, we were unable to apply contrast-enhanced ultrasound, which is useful for evaluating ablation effectiveness and the need for further treatment, due to the unavailability of ultrasonographic contrast agents in our country. CONCLUSION Regarding the significant decrease in volume, a significant improvement of clinical status, and fewer complications, both radiofrequency ablation and microwave ablation are both effective and safe methods in managing BTNs. Increased volume reduction rate were observed at 1 and 3 months follow‑up in the MWA group by the same radiologist. Abbreviations FNA Fine Needle Aspiration FNAC Fine-Needle Aspiration Cytology MWA Microwave Ablation RFA Radiofrequency Ablation US Ultrasound VRR Volume Reduction Rate Declarations Author Contribution N.E. wrote the main manuscript, collected the data and did statisticsO.H. the primary operator and recruiter of the cases M.G. revised the figures and statistics.A.S. revised the data of the cases.All authors revised the manuscript References Cheng, Z., Che, Y., Yu, S., Wang, S., Teng, D., Xu, H., ... & Liang, P. (2017). US-guided percutaneous radiofrequency versus microwave ablation for benign thyroid nodules: a prospective multicenter study. Scientific reports, 7(1), 9554. Cerit, M. N., Yücel, C., Cerit, E. T., Yalçın, M. M., Şendur, H. N., & Oktar, S. Ö. (2023). Comparison of the efficiency of radiofrequency and microwave ablation methods in the treatment of benign thyroid nodules. Academic Radiology, 30(10), 2172-2180. Yue, W. W., Wang, S. R., Lu, F., Sun, L. P., Guo, L. H., Zhang, Y. L., ... & Xu, H. X. (2017). Radiofrequency ablation vs. microwave ablation for patients with benign thyroid nodules: a propensity score matching study. Endocrine, 55, 485-495. Garberoglio, R., Aliberti, C., Appetecchia, M., Attard, M., Boccuzzi, G., Boraso, F., & Zingrillo, M. (2015). Radiofrequency ablation for thyroid nodules: which indications? The first Italian opinion statement. Journal of ultrasound, 18, 423-430. Lee, M. T., & Wang, C. Y. (2013). Radiofrequency ablation in nodular thyroid diseases. Journal of Medical Ultrasound, 21(2), 62-70. Bini, F., Pica, A., Marinozzi, F., Giusti, A., Leoncini, A., & Trimboli, P. (2023). Model-Optimizing Radiofrequency Parameters of 3D Finite Element Analysis for Ablation of Benign Thyroid Nodules. Bioengineering, 10(10), 1210. Vorländer, C., David Kohlhase, K., Korkusuz, Y., Erbelding, C., Luboldt, W., Baser, I., & Korkusuz, H. (2018). Comparison between microwave ablation and bipolar radiofrequency ablation in benign thyroid nodules: differences in energy transmission, duration of application and applied shots. International Journal of Hyperthermia, 35(1), 216–225. https://doi.org/10.1080/02656736.2018.1489984 Balasubramanian, S. P. (2024). Anatomy of the thyroid, parathyroid, pituitary and adrenal glands. Surgery (Oxford). Mauri, G., Hegedüs, L., Bandula, S., Cazzato, R. L., Czarniecka, A., Dudeck, O., & Papini, E. (2021). European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 clinical practice guideline for the use of minimally invasive treatments in malignant thyroid lesions. European thyroid journal, 10(3), 185-197. Hu, L., Li, T., Yin, X. L., & Zou, Y. (2020). An analysis of the correlation between thyroid nodules and metabolic syndrome. Endocrine Connections, 9(9), 933-938. Kim, S. Y., Hwa Han, K., Jung Moon, H., Young Kwak, J., Youn Chung, W., & Kim, E. K. (2014). Thyroid nodules with benign findings at cytologic examination: results of long-term follow-up with US. Radiology, 271(1), 272-281. Spiezia, S., Garberoglio, R., Milone, F., Ramundo, V., Caiazzo, C., Assanti, A. P., & Faggiano, A. (2009). Thyroid nodules and related symptoms are stably controlled two years after radiofrequency thermal ablation. Thyroid, 19(3), 219-225. Germano, A., Schmitt, W., Carvalho, M. R., & Marques, R. M. (2019). Normal ultrasound anatomy and common anatomical variants of the thyroid gland plus adjacent structures—A pictorial review. Clinical Imaging, 58, 114-128. Korkusuz, Y., Gröner, D., Raczynski, N., Relin, O., Kingeter, Y., Grünwald, F., & Happel, C. (2018). Thermal ablation of thyroid nodules: are radiofrequency ablation, microwave ablation and high intensity focused ultrasound equally safe and effective methods?. European Radiology, 28, 929-935. Guo, D. M., Chen, Z., Zhai, Y. X., & Su, H. H. (2021). Comparison of radiofrequency ablation and microwave ablation for benign thyroid nodules: A systematic review and meta‐analysis. Clinical Endocrinology, 95(1), 187-196. Goldberg, S. N. (2001). Radiofrequency tumor ablation: principles and techniques. European Journal of Ultrasound, 13(2), 129-147. https://doi.org/10.1016/S0929-8266(01)00044-0 . Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 18 Jun, 2025 Read the published version in Egyptian Journal of Radiology and Nuclear Medicine → 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-5383714","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":433978314,"identity":"0efcb136-8d09-492c-a741-9a67926ce67e","order_by":0,"name":"Nouran Elghitany","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1klEQVRIiWNgGAWjYNCCCgk5efYGIMPAglgtZyyMDXsOgLRIEKmDsa0iseFGAohJhBZz9t6HnwvYJBIbZz6/uuFHgQQDf3t3Al4tlj3HjaVn8EgYt0vnlN3sATpM4szZDXi1GNxIY5DmkZCQbZydk3aDB6jFQCKXoBbm30CVjA03z6Td/EOkFjZpngQJxYYb7MduE2fLmWNs1jwHJICBnMN2W8ZAgoewX463Md/m/VcHjMrjz26++WMjx9/ei18LEuAxAJPEKgcB9gekqB4Fo2AUjIIRBAAGpURcZPZ1awAAAABJRU5ErkJggg==","orcid":"","institution":"Ain Shams University Hospital","correspondingAuthor":true,"prefix":"","firstName":"Nouran","middleName":"","lastName":"Elghitany","suffix":""},{"id":433978316,"identity":"8c1ade9d-821f-419f-89be-3b3ea8f30134","order_by":1,"name":"Osama Hetta","email":"","orcid":"","institution":"Ain Shams University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Osama","middleName":"","lastName":"Hetta","suffix":""},{"id":433978317,"identity":"fe11200d-4824-469b-85d6-fd5bb8c0725a","order_by":2,"name":"Mohamed Gamaleldin","email":"","orcid":"","institution":"Ain Shams University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Mohamed","middleName":"","lastName":"Gamaleldin","suffix":""},{"id":433978318,"identity":"67eb743d-fa74-4311-9446-d82df9add039","order_by":3,"name":"Asaad Sorial","email":"","orcid":"","institution":"Ain Shams University Hospital","correspondingAuthor":false,"prefix":"","firstName":"Asaad","middleName":"","lastName":"Sorial","suffix":""}],"badges":[],"createdAt":"2024-11-03 22:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5383714/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5383714/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s43055-025-01503-3","type":"published","date":"2025-06-18T15:57:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":79255587,"identity":"07068bcc-8732-4b00-aaa7-00f6286c55a0","added_by":"auto","created_at":"2025-03-26 08:54:02","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":31771,"visible":true,"origin":"","legend":"\u003cp\u003eCompressive ten-centimeters visual analog scale\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/1dd9c85ed72eae836daa6df0.jpg"},{"id":79255585,"identity":"5412ea6c-6b73-4cf5-a815-359a1a1cf066","added_by":"auto","created_at":"2025-03-26 08:54:01","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":153316,"visible":true,"origin":"","legend":"\u003cp\u003e(a , b) showing Hydro dissection was done using a 22G spinal needle and (c ) showing transverse ultrasound image demonstrates ablation of the periphery of a deep ,remote portion and center of the of the nodule (d). The transverse ultrasound image demonstrates relocation of the electrode tip in the more proximal, unmanaged area (moving shot technique)\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/fe011cd9f0a1d0aa0b844064.jpg"},{"id":79255582,"identity":"6dda7f04-3f25-40a8-bd79-aefc28d9384e","added_by":"auto","created_at":"2025-03-26 08:54:01","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":117973,"visible":true,"origin":"","legend":"\u003cp\u003e(a) showing a solid thyroid nodule before MWA (b) showing the line of demarcation (white arrows) between the hypoechoic ablated area after the procedure and the hyperechoic unablated periphery of the nodule.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/31af39d21b8443578b708938.jpg"},{"id":79255588,"identity":"16ff8059-d5c9-4394-8df3-8ea6e9b2a305","added_by":"auto","created_at":"2025-03-26 08:54:02","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":65633,"visible":true,"origin":"","legend":"\u003cp\u003eShows reduction rate% in size between two study groups.\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/f0a39a26e2ac2c5f1fc4ccc3.jpg"},{"id":79256809,"identity":"5bd6957f-6d81-49d8-835a-50e2ae594950","added_by":"auto","created_at":"2025-03-26 09:02:06","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":67564,"visible":true,"origin":"","legend":"\u003cp\u003eShows reduction rate% in compressive between two study groups.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/aceb21e0ca03a4d79a33aaec.jpg"},{"id":79255597,"identity":"594b56c7-fd61-4cda-b602-c3da781b3ab4","added_by":"auto","created_at":"2025-03-26 08:54:06","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":61441,"visible":true,"origin":"","legend":"\u003cp\u003eShows reduction rate% in cosmetic between two study groups.\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/4c0f2ba4f578b87223f50a99.jpg"},{"id":79256812,"identity":"33973a66-8e2f-4b2d-a479-58738ed8f8e3","added_by":"auto","created_at":"2025-03-26 09:02:06","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":104943,"visible":true,"origin":"","legend":"\u003cp\u003eA 28-year-old female case had complained of large left neck bulge because of BTNs. \u0026nbsp;a Prior to RF ablation. b 3 months after RF ablation.\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/79a9fb3ae8d140229dc87015.jpg"},{"id":79255595,"identity":"952ec61c-a2b0-4d7b-9ccc-f5c0786183f7","added_by":"auto","created_at":"2025-03-26 08:54:06","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":164796,"visible":true,"origin":"","legend":"\u003cp\u003ea and b show a mixed nodule echotexture just before ablation with average volume of about 45 ml c and d shows the volume and ultrasound echopattern 3 months after follow up with average volume of about 12 ml. note how the nodule becomes hypoechoic after RF ablation.\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/64c1c84a8b1d3ca848fb5cc3.jpg"},{"id":79255601,"identity":"8de41acc-40de-44e3-b82b-6c7415d0ac8f","added_by":"auto","created_at":"2025-03-26 08:54:06","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":98489,"visible":true,"origin":"","legend":"\u003cp\u003eA benign thyroid nodule resulted in recurrent neck bulging in a 51-year-old female case. a Prior to MWA ablation. b 3 month after MWA ablation.\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/db6652577f26ea09b5293f23.jpg"},{"id":79256811,"identity":"e669492c-2bbb-4184-8456-42602922f4dc","added_by":"auto","created_at":"2025-03-26 09:02:06","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":148375,"visible":true,"origin":"","legend":"\u003cp\u003eA 51-year-old female cases had complained of recurrent neck bulging because of benign thyroid nodule. a Prior to MWA ablation. b 3 months after MWA ablation,\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/e03b9ce31714fe54c8072122.jpg"},{"id":85231449,"identity":"3de098d7-f65e-4135-b1c5-650fe510fa58","added_by":"auto","created_at":"2025-06-23 16:08:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2152294,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5383714/v1/6d07c394-e58b-47cc-a6ca-87476ae6a969.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Efficacy and Safety of Ultrasound Guided Microwave versus Radiofrequency Ablation of Benign Thyroid Nodules","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eWithin the past two decades, the widespread application of radiological imaging has resulted in the increased detection of incidental finding of benign thyroid nodules in approximately half of the general population through ultrasound assessment, which is one of the most common lesions in clinical practice. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] Benign thyroid nodules are usually asymptomatic. However, some nodules cause compression symptoms, cosmetic or psychological problems. In these cases, interventions including surgical and nonsurgical procedures will be recommended. [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] Despite the fact that surgery is an effective measure for the management of thyroid nodules, it has a risk of 2\u0026ndash;10% to cause hypothyroidism and neck scarring. Other listed complications are bleeding, hypocalcemia, permanent recurrent laryngeal nerve palsy, hypocalcemia and postoperative infections. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] Another traditional therapeutic technique is radioiodine treatment, which additionally carries the risk of after-management nausea, hypothyroidism, and need for isolation. For these reasons, a several cases with thyroid nodules seek for alternative therapy techniques, including percutaneous thermal ablation, which is minimally invasive and doesn\u0026rsquo;t need radioactive substances or general anesthesia. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] Radiofrequency ablation and microwave ablation are the most frequently utilized percutaneous thermal ablation methods for thyroid tissue. The basic principle of both approaches is to induce thermal damage by heating the tissue to induce thermal coagulative necrosis of the tissue around the needle tip [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eRFA was first introduced in 2006 which since then was stated to be both effective and safe for managing benign thyroid nodules by generating friction and conductive heat using high- frequency alternating electric current oscillating between 200 and 1200 kilohertz. The tissue immediately adjacent to the electrode point is affected by the frictional heat, whereas the conduction heat from the ablation area spreads more insidiously to the surrounding tissues, resulting in additional cell necrosis.\u003c/p\u003e \u003cp\u003eInternally cooled RF electrodes, featuring hollow lumens for continuous internal cooling, improve coagulation by reducing tissue heating near the electrode. This cooling effect minimizes tissue charring and impedance rises, enabling greater current deposition [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e][\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn comparison to RFA, microwave ablation is a percutaneous thermal ablation method which utilizes nonionizing electromagnetic radiation to heat nodular tissue. It has been shown to have the following benefits: a homogeneous ablated area, a decreased heat sink impact, significantly greater intralesional temperatures and decreased procedure period. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eThe advantages of the percutaneous thermal ablation technique include the ability to reduce the size of the lesions managed, the favorable cosmetic outcomes, and the absence of significant correlated complications, which prevents cases from requiring hospitalization. The method not only completely inactivates the lesion yet additionally protects the case's normal thyroid function from any inconvenience or trouble that may result from long-term administration of levothyroxine. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eAlthough percutaneous thermal ablation procedure was proven to be safe and effective in management of BTNs, there\u0026rsquo;s no organized knowledge in the medical field and society on the differences between RFA and MCA, since there are inconsistencies between how the techniques are applied among different countries. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] The objective of this investigation was to compare the efficacy of microwave and radiofrequency ablation procedures in the management of BTNs to share our clinical experiences.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003eThis prospective research comparing RFA and MWA and the utilization of these techniques has been accepted by the Ethics Committee of Ain Shams University Hospital. All patients undergoing percutaneous thermal ablation have been essential to sign and read an informed consent before the technique. (RFA or MWA) for BTNs from January 2022 to August 2024. A total of 38 cases have been managed with RFA, while a total of 43 cases have been managed with MWA. Inclusion criteria were as follow: (a) presence of either cosmetic or compressive problems, (b) ultrasound findings suggesting a benign nodule and benign cytologic confirmation by ultrasound ‑guided fine-needle aspiration cytology (FNAC), all nodules included was confirmed by cytology to be Bethesda II, if cytology results was Bethesda I a repeat FNAC was done, if III or more Ablation was differed(c) serum concentrations of thyrotropin and thyroid hormone in the normal range, and (d) refusal to undergo operation or contraindications for operation. Exclusion criteria were as follows: (a) cytologic results indicating malignancy, (b) the abnormal function of the vocal cord on the contralateral side of the lesion, and (d) Pregnancy and breast-feeding women.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEquipment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCanyon KY2000-A MCW generator from Canyon Medical Inc. used for MWA treatment. Mygen (M-3004) radiofrequency generator from radiofrequency Medical Co., Ltd, South Korea used for RFA treatment. The microwave antenna was 18 G, and the RFA electrode was 18 G.\u003c/p\u003e\n\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003ePreablation assessment\u003c/h2\u003e\n \u003cp\u003eBefore ablation, ultrasound was performed by an experienced radiologist in thyroid imaging. Thyroid tumors have been carefully assessed for their morphology, structure, components (completely cystic, completely solid, or mixed with the two components and volume. The 3 diameters of each nodule (such as, two other perpendicular diameters and the largest diameter) have been determined by US to directly determine volume of each nodule. The nodule volumes have been subsequently determined utilizing the following equation: \u0026pi;abc/6, where (a) represents the largest diameter and (b) and (c) represent the other two perpendicular diameters. Subsequently, US-guided FNAC, laboratory tests, and clinical states were conducted to confirm the benign nature of the nodules, transcutaneous laryngeal ultrasound was performed to evaluate the vocal fold structure and function and laboratory examinations involved thyroid function (for examples, serum thyroid-stimulating hormone [TSH], free triiodothyronine [FT3], free thyroxine [FT4], blood coagulation tests and complete blood count. Moreover, every patient was evaluated for their cosmetic scores, which were as follows: Score 1: no palpable mass; Score 2: no cosmetic problem but a palpable mass; Score 3: cosmetic problem on swallowing only; and Score 4: a readily noticeable cosmetic problem. On a visual analog scale of 10 centimeters, cases self-report their symptomatic concerns, with a score of 0 indicating that they do not suffer from any symptoms or pain and [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e] corresponding to agonizing and excruciating pressure symptoms. (Fig. 1)\u003c/p\u003e\n\u003c/div\u003e\n\u003ch3\u003eProcedure\u003c/h3\u003e\n\u003cp\u003eTreatment procedures have been conducted as an outpatient procedure by an experienced radiologist in RFA and MWA. Just prior to the technique, a one dosage of anti-edematous medication (hydrocortisone sodium succinate) and an IV antibiotic (sulbactam/ampicillin) was administered to each case. The cases have been positioned in the supine position with mild hyperextended neck and administered local anesthesia via subcutaneous injection. Hydro dissection was done using a 22G spinal needle with cold 5% glucose infused into the surrounding thyroid capsule under US guidance to achieve a \u0026ldquo;liquid isolating region\u0026rdquo; and to protect the vital structures of the neck (trachea, carotid artery, recurrent laryngeal nerve and esophagus,) from thermal damage.\u003c/p\u003e\n\u003cp\u003eIn nodules with retrosternal extension, the ablation starts from the most cranial part of the nodule as we notice that the retrosternal portion shifts up making it safer to ablate as well as repeating hydro dissection before starting to ablate the caudal portion. If the nodule was mainly cystic, the needle for fluid aspiration and the ablation probe were inserted simultaneously and the aspiration was performed first followed by removal of the needle and starting ablation of the walls of the cyst. In isthmic nodule in addition to hydro-dissection we would also use continuous irrigation with cold saline of the skin to minimize the heating effect to the skin. Ablation of the feeding artery was not a routine part of this study.\u003c/p\u003e\n\u003cp\u003eThe output powers for radiofrequency ablation and microwave ablation have been set between 40-100W and 30\u0026ndash;50 watts, respectively. The \u0026quot;moving-shot method\u0026quot; was utilized during the technique, and the antenna or electrode was moved unit-by-unit to address each nodule in a manner known as the conceptual ablation units. The whole treatment was monitored using real-time US, and the ablation has been stopped when the entire nodule was ablated, and transient hyperechoic areas were observed all through the nodule [Figure 2].in MWA after the procedure we can see that the ablated area became hypoechoic which helps in confirmation of good ablation [Figure 3].\u003c/p\u003e\n\u003ch3\u003ePost ablation evaluation and data analysis\u003c/h3\u003e\n\u003cp\u003eAll patients got out in 30 minutes of the technique, involving those that had been anesthetized but had recovered fully. Cases were advised to continue using ice packs on the puncture site for approximately one hour. All cases were prescribed oral antibiotics (Clavulanate potassium\u0026thinsp;+\u0026thinsp;Amoxycillin) and analgesics (Paracetamol) for a period of one week following the surgery. Clinical symptoms and signs were used to evaluate complications both during surgery and following surgery. The thyroid profile, ultrasound evaluation of the thyroid nodule, cosmetic problem, and compressive symptoms had been assessed during the monitoring at one, three, six, and twelve months. The volume reduction rates were determined using the following equation: volume reduction ratio (%) = (initial volume (milliliter) - final volume (milliliter) / initial volume (ml). This was done through ultrasound imaging.\u003c/p\u003e\n\u003cp\u003eFor the statistical analysis, the data gathered was reviewed, coded, tabulated, and entered a PC utilizing the Statistical Package for the Social Sciences (SPSS 27). Data was expressed, and appropriate assessment was conducted based on the type of data acquired for each of the variables. Quantitative data were presented as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation. Parameters from pre-ablation, post-ablation, and monitoring have been analyzed utilizing a paired t-test. An independent-sample t-test was conducted to compare age, nodular volume, VRR, and symptom and cosmetic scores among both groups. The gender distribution, nodule location, nodule composition, and complications were examined utilizing the Chi-square test. A P-value of less than 0.05 was defined statistically significant.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eBaseline characteristics of the microwave ablation and radiofrequency ablation groups. Patients with TNs have been managed with percutaneous thermal ablation in our hospital. Cases were categorized into the RFA group (number\u0026thinsp;=\u0026thinsp;38) and the MWA group (number\u0026thinsp;=\u0026thinsp;43) based on the first therapy approach. The baseline characteristics of the patients enrolled in the two groups are shown in Table\u0026nbsp;1. The radiofrequency ablation group consisted of 26 females and 12 males (mean age: 42.58\u0026thinsp;\u0026plusmn;\u0026thinsp;15.8). The microwave ablation group consisted of 32 females and 11 males (mean age: 45.77\u0026thinsp;\u0026plusmn;\u0026thinsp;15.03). Prior to therapy, also insignificant variances among the RFA and MWA ablation groups regarding other US characteristics and clinical characteristics.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;(1)\u003c/strong\u003e:\u003c/p\u003e\n\u003ctable id=\"Taba\" border=\"1\"\u003e\n \u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"3\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMicrowave\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eN (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eN (%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003eSide\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eRight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e17 (44.74%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15 (34.88%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLeft\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e21 (55.26%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e25 (58.14%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIsthmus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0 (0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (6.98%) (18)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"3\"\u003e\n \u003cp\u003eConsistency\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e24 (63.16%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e29 (67.44%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCystic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e(20) 3 (7.89%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (6.98%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMixed\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11 (28.95%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11 (25.58%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eRetrosternal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e30 (78.95%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e35 (81.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 (21.05%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e8 (18.6%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eAge\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e42.58\u0026thinsp;\u0026plusmn;\u0026thinsp;15.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e45.77\u0026thinsp;\u0026plusmn;\u0026thinsp;15.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"2\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e12 (31.58%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11 (25.58%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e26 (68.42%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e32 (74.42%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003ch3\u003eResults after followup\u003c/h3\u003e\n\u003cp\u003eAt 1, 3, 6, and 12 months, the mean volumes of the ablated nodule in the two groups were significantly lesser than the mean volumes before ablation. The VRRs between the radiofrequency ablation group and microwave ablation group at one, three, six, and twelve months were were 53.1% \u0026plusmn; 11.2% vs. 45.8% \u0026plusmn; 13.5% (P\u0026thinsp;=\u0026thinsp;0.009), 67.9% \u0026plusmn; 11.5%vs. 61.8% \u0026plusmn; 12.8% (P\u0026thinsp;=\u0026thinsp;0.027), 77.5% \u0026plusmn; 9.7%vs. 73.4% \u0026plusmn; 11% (P\u0026thinsp;=\u0026thinsp;0.084), and 85.4% \u0026plusmn; 7.6% vs. 83.6% \u0026plusmn; 6.4% (P\u0026thinsp;=\u0026thinsp;0.252), respectively. The mean nodular volume reduction rates showed significant difference that the microwave ablation group achieved greater VRRs compared to that of the radiofrequency ablation group at 1 and 3 months follow up by the same radiologist.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;(2)\u003c/strong\u003e: Relation between two study groups) at different time points\u003c/p\u003e\n\u003ctable id=\"Tabb\" border=\"1\"\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"3\"\u003e\n \u003cp\u003e`\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"2\"\u003e\n \u003cp\u003eTest of significance\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMicrowave\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSig.\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"4\"\u003e\n \u003cp\u003eReduction Rate %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e45.8% \u0026plusmn; 13.5%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e53.1% \u0026plusmn; 11.2%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.009\u003csup\u003e\u003cstrong\u003e[T]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e61.8% \u0026plusmn; 12.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e67.9% \u0026plusmn; 11.5%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.027\u003csup\u003e\u003cstrong\u003e[T]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e73.4% \u0026plusmn; 11%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e77.5% \u0026plusmn; 9.7%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.084\u003csup\u003e\u003cstrong\u003e[T]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 12 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e83.6% \u0026plusmn; 6.4%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e85.4% \u0026plusmn; 7.6%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.252\u003csup\u003e\u003cstrong\u003e[T]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eRepeated measures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003csup\u003e\u0026nbsp;\u003cstrong\u003e[T]\u003c/strong\u003e\u0026nbsp;\u003c/sup\u003e Student t-test of significance.\u003c/p\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003eSymptom score, cosmetic score, and complications:\u003c/h2\u003e\n \u003cp\u003eInsignificant variance in the symptom score (compressive reduction rate) among the RFA group and the MWA group at one, three, six, and twelve months, [Figure 5]. The cosmetic score between the radiofrequency ablation group and the microwave ablation group demonstrated statistically insignificant differences at one, three, six, and twelve ‑month monitoring visits, [Fig.\u0026nbsp;6]. A significant improvement of symptom and cosmetic score was found after thermal ablation at last follow-up (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) ( Table\u0026nbsp;3, 4).\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;(3)\u003c/strong\u003e: Relation between two study groups and difference in compressive at different time points\u003c/p\u003e\n \u003ctable id=\"Tabc\" border=\"1\"\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"3\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"2\"\u003e\n \u003cp\u003eTest of significance\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMicrowave\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSig.\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"5\"\u003e\n \u003cp\u003eCompressive\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-ablation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 (4\u0026ndash;7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5 (3\u0026ndash;7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.294\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (3\u0026ndash;4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (2\u0026ndash;4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.248\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (2\u0026ndash;3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.178\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.259\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 12 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0 (0\u0026ndash;1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0 (0\u0026ndash;0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.256\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eRepeated measures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003csup\u003e\u0026nbsp;\u003cstrong\u003e[M]\u003c/strong\u003e\u0026nbsp;\u003c/sup\u003e Mann-Whitney test of significance.\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;(4)\u003c/strong\u003e: Relation between two study groups and difference in cosmetic at different time points\u003c/p\u003e\n\u003ctable id=\"Tabd\" border=\"1\"\u003e\n \u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"3\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\" rowspan=\"2\"\u003e\n \u003cp\u003eTest of significance\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eRF\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMicrowave\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard deviations\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003ep-value\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSig.\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" rowspan=\"5\"\u003e\n \u003cp\u003eCosmetic\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePre-ablation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (4\u0026ndash;4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 (3\u0026ndash;4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.074\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 1 month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 (2\u0026ndash;3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.770\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 3 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.400\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 6 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (1\u0026ndash;2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.316\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAfter 12 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (1\u0026ndash;1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1 (1\u0026ndash;1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.225\u003csup\u003e\u003cstrong\u003e[M]\u003c/strong\u003e\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNS\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003eRepeated measures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003e\u003csup\u003e\u0026nbsp;\u003cstrong\u003e[M]\u003c/strong\u003e\u0026nbsp;\u003c/sup\u003e Mann-Whitney test of significance.\u003c/p\u003e\n \u003cp\u003eComplications were observed in 3 of the 81 patients after ablation. Two patients had Voice change occurred, one in each group. The alterations in voice have been transient and completely recovered following approximately two weeks, corresponding with the partial absorption of edema by the tissues. In addition, a single patient in the RFA group had minor skin burn and recovered totally in 1 month. Thyroid function including serum TSH, FT3 and FT4 remained stable. Infection, hemorrhage, and tracheal and esophageal injury after ablation were not observed. Hypothyroidism and autoimmune thyroid disease were not observed at follow-up.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThyroid nodules are prevalent in the general people, with ultrasound being the primary imaging method for their evaluation. This technique has significantly increased the detection of such nodules \u003cstrong\u003e[10].\u0026nbsp;\u003c/strong\u003eLarger nodules may cause pressure-related symptoms, leading to cosmetic concerns, neck discomfort, and a diminished quality of life. So far, total or partial thyroidectomy were the main treatment options. While surgery is widely accessible and generally safe in experienced hands, complications both permanent and temporary can happen within two to ten percent of cases. Total thyroidectomy invariably results in hypothyroidism, necessitating lifelong levo-thyroxine therapy. Moreover, surgery may not be suitable for high-risk patients or may be declined by some individuals\u0026nbsp;\u003cstrong\u003e[2]\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003ePercutaneous thermal ablation defined as a safe and effective option for symptomatic BTNs\u0026nbsp;\u003cstrong\u003e[2]\u003c/strong\u003e. A single benign diagnosis from fine needle aspiration (FNA) is adequate when the nodule displays ultrasound characteristics strongly indicative of benignity (e.g., isoechoic spongiform or partially cystic nodules with intracystic comet tail artifacts) \u003cstrong\u003e[11].\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWhile percutaneous thermal ablation doesn’t provide immediate removal of thyroid nodules, it induces necrosis and gradual shrinkage of the nodules, leading to volume reduction and symptom improvement, with the effectiveness of radiofrequency ablation comparable to surgical options \u003cstrong\u003e[12]\u003c/strong\u003e. Research has shown variable outcomes regarding the average volume reduction of thyroid nodules and the variances in volume reduction rates between\u0026nbsp;radiofrequency ablation\u0026nbsp;and microwave ablation. Factors influencing these results include the operator's experience, nodule composition, energy delivered, and duration of the procedure. The aim of this study is to compare the efficacy and safety of ultrasound-guided RF ablation versus microwave ablation for treating benign thyroid nodules.\u003c/p\u003e\n\u003cp\u003eIn our study, 81 cases with 81 nodules underwent ultrasound-guided thermal ablation using either RFA or MWA. We compared the volume reduction rates in both groups at\u0026nbsp;one, three, six, and twelve months, finding statistically significant reductions in both groups, with the MWA group showing greater volume reduction at 1 and 3 months. Literature indicates that VRR after RF ablation ranges from 50% to 88.2% between 6- and 18-months post-treatment\u0026nbsp;\u003cstrong\u003e[13]\u003c/strong\u003e. A pooled VRR of 63% was observed at twelve months post-ablation in a meta-analysis that included 7 MWA investigations, which included 1146 participants and 1226 nodules\u0026nbsp;\u003cstrong\u003e[2]\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eFew studies compare MWA and RFA efficacy directly, with VRR often serving as the measure of effectiveness. Results can differ based on the monitoring duration. \u003cstrong\u003e\u003cem\u003eKorkusuz et al.\u0026nbsp;\u003c/em\u003e[14]\u0026nbsp;\u003c/strong\u003efound higher\u0026nbsp;volume reduction rates with RF at 3 months, while \u003cstrong\u003e\u003cem\u003eVorländer et al.\u003c/em\u003e [7]\u0026nbsp;\u003c/strong\u003estated insignificant differences among the methods at that time point. \u003cstrong\u003e\u003cem\u003eCheng et al.\u0026nbsp;\u003c/em\u003e[1]\u003c/strong\u003e also noted no differences at 3 months, but RF showed higher VRRs between 6 and 12 months. \u003cstrong\u003e\u003cem\u003eYue et al.\u003c/em\u003e\u003c/strong\u003e \u003cstrong\u003e[3]\u0026nbsp;\u003c/strong\u003esimilarly found no differences during the12 months follow up. A recent meta-analysis found no differences at 3 and 6 months but noted that RF had a higher\u0026nbsp;volume reduction rate at twelve months. These studies confirm that both techniques are effective to manage BTNs.\u003c/p\u003e\n\u003cp\u003eThe mean\u0026nbsp;volume reduction rate of the\u0026nbsp;radiofrequency ablation group compared to the\u0026nbsp;microwave ablation group at the three, six, and twelve months, as well as the final monitoring, were 67.6 ± 20.3% versus 64.4 ± 43.5% (p-value = 0.143), 84.1 ± 13.5% versus 78.4 ± 48.2% (p-value = 0.016), 89.6 ± 20.0% versus 82.5 ± 49.7% (p-value = 0.035), and 91.3 ± 12.6% versus 81.1 ± 70.4% (p-value = 0.045), respectively. At the third month of monitoring, the mean nodular\u0026nbsp;volume reduction rate didn't demonstrate significant variance among both groups. However, statistical significance has been observed at the sixth and following months of monitoring, and the RFA group demonstrated a greater\u0026nbsp;volume reduction rate compared to the\u0026nbsp;microwave ablation group.\u0026nbsp;While in our study the mean VRRs of the MWA group versus the RFA group at 1, 3, 6, and 12 months were 53.1% ± 11.2% versus 45.8% ± 13.5% (P =0.009), 67.9% ± 11.5% versus 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7% versus 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% versus 83.6% ± 6.4% (P = 0.252), respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn our findings, the mean VRRs for the MWA and RF groups at 1, 3, 6, and 12 months were 53.1% ± 11.2% vs. 45.8% ± 13.5% (P = 0.009), 67.9% ± 11.5% vs. 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7% vs. 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% vs. 83.6% ± 6.4% (P = 0.252), respectively (figure 7 and 8)\u003c/p\u003e\n\u003cp\u003eIn contrast to some literature, our study indicated that the MWA technique outperformed RF according to\u0026nbsp;volume reduction rate at the 1- and 3-month follow-ups. Differences in clinical outcomes may stem from the technical distinctions between RF and\u0026nbsp;microwave ablation and the completion of peripheral ablation. Effective treatment requires comprehensive ablation of the entire nodule, influenced by the nodule's size, its proximity to critical structures, and its composition. MWA offers a faster temperature and larger ablation volume rise comparing with RF, making it particularly advantageous for larger nodules and reducing treatment time. Its predictable and homogeneous ablation zone may also lower the probability of injury to nearby vital structures.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn studies by \u003cstrong\u003e\u003cem\u003eKorkusuz et al.\u0026nbsp;\u003c/em\u003e[14]\u003c/strong\u003e and\u0026nbsp;\u003cstrong\u003e\u003cem\u003eVorländer et al.\u003c/em\u003e [7]\u0026nbsp;\u003c/strong\u003ethat utilized twenty-four to thirty-six watts of microwave power, insignificant differences within volume reduction rate were observed among microwave ablation and RF at the 3-month monitoring. \u003cstrong\u003e\u003cem\u003eYue et al.\u003c/em\u003e\u003c/strong\u003e \u003cstrong\u003e[3]\u003c/strong\u003e additionally found no differences after 6 months with similar power outputs. In Snomez et al.'s research, that employed 60-140 watts, no differences in VRR were noted with RF after 1 month. These findings suggest that adjusting power output during MWA can minimize carbonization and enhance nodule resorption. Within our research, using a relatively low microwave power output (40-50 W) resulted in nodule shrinkage, likely because MWA is preferred for larger nodules.\u003c/p\u003e\n\u003cp\u003eAnother challenge with MWA is the back-heating effect from reflected waves, particularly with a 16G needle, which can produce a 2-cm back-heating zone. We mitigated this issue by utilizing 18G antennas, resulting in an increased VRR for the MWA technique.\u003c/p\u003e\n\u003cp\u003eThe complex neck anatomy, with multiple critical structures like the recurrent laryngeal nerve, major vessels, and trachea, necessitates that operators possess a thorough understanding of each thermal ablation technique and expertise in cervical ultrasound anatomy to avoid severe complications\u0026nbsp;\u003cstrong\u003e[7]\u003c/strong\u003e. Various complications associated with RF and MWA have been documented, involving hematomas, skin burns,\u0026nbsp;voice changes, and infections. \u003cstrong\u003e\u003cem\u003eGuo et al.\u0026nbsp;\u003c/em\u003e[15]\u003c/strong\u003e conducted a meta-analysis that confirmed that MWA is as safe as RF for the treatment of benign thyroid nodules, as there were insignificant variances in minor or major complications among the two procedures \u003cstrong\u003e[2]\u003c/strong\u003e. \u003cstrong\u003e\u003cem\u003eHe et al.\u003c/em\u003e\u003c/strong\u003e conducted an additional meta-analysis of randomized controlled investigations and discovered that there was insignificant difference in the total complication rates of less-invasive management methods. The complication rates in the present investigation were minimal, consistent with the existing literature. Insignificant variances have been observed among the RFA (5.2%) and MWA (2.3%) groups.\u003c/p\u003e\n\u003cp\u003eWe aimed to address limitations observed in other studies, such as those noted by \u003cstrong\u003e\u003cem\u003eCerit et al.\u0026nbsp;\u003c/em\u003e[2]\u003c/strong\u003e by conducting a prospective study with similar nodule characteristics, including consistency, age, and gender, along with routine and consistent patient follow-up. Additionally, since MWA is typically favored for high-volume nodules, the mean nodule volume in the\u0026nbsp;microwave ablation\u0026nbsp;group was higher.\u003c/p\u003e\n\u003cp\u003eThe relatively small sample size in each group was the primary limitation of the present research. A larger sample size could be beneficial to strengthen our conclusions. Furthermore, we were unable to apply contrast-enhanced ultrasound, which is useful for evaluating ablation effectiveness and the need for further treatment, due to the unavailability of ultrasonographic contrast agents in our country.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eRegarding the significant decrease in volume, a significant improvement of clinical status, and fewer complications, both radiofrequency ablation and microwave ablation are both effective and safe methods in managing BTNs. Increased volume reduction rate were observed at 1 and 3 months follow‑up in the MWA group by the same radiologist.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eFNA\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Fine Needle Aspiration\u003c/p\u003e\n\u003cp\u003eFNAC\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Fine-Needle Aspiration Cytology\u003c/p\u003e\n\u003cp\u003eMWA\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Microwave Ablation\u003c/p\u003e\n\u003cp\u003eRFA\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Radiofrequency Ablation\u003c/p\u003e\n\u003cp\u003eUS\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Ultrasound\u003c/p\u003e\n\u003cp\u003eVRR \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; Volume Reduction Rate\u0026nbsp;\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eN.E. wrote the main manuscript, collected the data and did statisticsO.H. the primary operator and recruiter of the cases M.G. revised the figures and statistics.A.S. revised the data of the cases.All authors revised the manuscript\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003e\u003cstrong\u003eCheng, Z., Che, Y., Yu, S., Wang, S., Teng, D., Xu, H., ... \u0026amp; Liang, P. (2017).\u003c/strong\u003e US-guided percutaneous radiofrequency versus microwave ablation for benign thyroid nodules: a prospective multicenter study. Scientific reports, 7(1), 9554.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eCerit, M. N., Y\u0026uuml;cel, C., Cerit, E. T., Yal\u0026ccedil;ın, M. M., Şendur, H. N., \u0026amp; Oktar, S. \u0026Ouml;. (2023). \u003c/strong\u003eComparison of the efficiency of radiofrequency and microwave ablation methods in the treatment of benign thyroid nodules. Academic Radiology, 30(10), 2172-2180.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eYue, W. W., Wang, S. R., Lu, F., Sun, L. P., Guo, L. H., Zhang, Y. L., ... \u0026amp; Xu, H. X. (2017). \u003c/strong\u003eRadiofrequency ablation vs. microwave ablation for patients with benign thyroid nodules: a propensity score matching study. Endocrine, 55, 485-495.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eGarberoglio, R., Aliberti, C., Appetecchia, M., Attard, M., Boccuzzi, G., Boraso, F., \u0026amp; Zingrillo, M. (2015). \u003c/strong\u003eRadiofrequency ablation for thyroid nodules: which indications? The first Italian opinion statement. Journal of ultrasound, 18, 423-430.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eLee, M. T., \u0026amp; Wang, C. Y. (2013). \u003c/strong\u003eRadiofrequency ablation in nodular thyroid diseases. Journal of Medical Ultrasound, 21(2), 62-70.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eBini, F., Pica, A., Marinozzi, F., Giusti, A., Leoncini, A., \u0026amp; Trimboli, P. (2023). \u003c/strong\u003eModel-Optimizing Radiofrequency Parameters of 3D Finite Element Analysis for Ablation of Benign Thyroid Nodules. Bioengineering, 10(10), 1210.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eVorl\u0026auml;nder, C., David Kohlhase, K., Korkusuz, Y., Erbelding, C., Luboldt, W., Baser, I., \u0026amp; Korkusuz, H. (2018).\u003c/strong\u003e Comparison between microwave ablation and bipolar radiofrequency ablation in benign thyroid nodules: differences in energy transmission, duration of application and applied shots. International Journal of Hyperthermia, 35(1), 216\u0026ndash;225. https://doi.org/10.1080/02656736.2018.1489984\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eBalasubramanian, S. P. (2024). \u003c/strong\u003eAnatomy of the thyroid, parathyroid, pituitary and adrenal glands. Surgery (Oxford).\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eMauri, G., Heged\u0026uuml;s, L., Bandula, S., Cazzato, R. L., Czarniecka, A., Dudeck, O., \u0026amp; Papini, E. (2021). \u003c/strong\u003eEuropean Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 clinical practice guideline for the use of minimally invasive treatments in malignant thyroid lesions. European thyroid journal, 10(3), 185-197.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eHu, L., Li, T., Yin, X. L., \u0026amp; Zou, Y. (2020). \u003c/strong\u003eAn analysis of the correlation between thyroid nodules and metabolic syndrome. Endocrine Connections, 9(9), 933-938.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eKim, S. Y., Hwa Han, K., Jung Moon, H., Young Kwak, J., Youn Chung, W., \u0026amp; Kim, E. K. (2014). \u003c/strong\u003eThyroid nodules with benign findings at cytologic examination: results of long-term follow-up with US. Radiology, 271(1), 272-281.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eSpiezia, S., Garberoglio, R., Milone, F., Ramundo, V., Caiazzo, C., Assanti, A. P., \u0026amp; Faggiano, A. (2009). \u003c/strong\u003eThyroid nodules and related symptoms are stably controlled two years after radiofrequency thermal ablation. Thyroid, 19(3), 219-225.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eGermano, A., Schmitt, W., Carvalho, M. R., \u0026amp; Marques, R. M. (2019). \u003c/strong\u003eNormal ultrasound anatomy and common anatomical variants of the thyroid gland plus adjacent structures\u0026mdash;A pictorial review. Clinical Imaging, 58, 114-128.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eKorkusuz, Y., Gr\u0026ouml;ner, D., Raczynski, N., Relin, O., Kingeter, Y., Gr\u0026uuml;nwald, F., \u0026amp; Happel, C. (2018). \u003c/strong\u003eThermal ablation of thyroid nodules: are radiofrequency ablation, microwave ablation and high intensity focused ultrasound equally safe and effective methods?. European Radiology, 28, 929-935.\u003c/li\u003e\n\u003cli\u003e\u003cstrong\u003eGuo, D. M., Chen, Z., Zhai, Y. X., \u0026amp; Su, H. H. (2021). \u003c/strong\u003eComparison of radiofrequency ablation and microwave ablation for benign thyroid nodules: A systematic review and meta‐analysis. Clinical Endocrinology, 95(1), 187-196.\u003c/li\u003e\n\u003cli\u003eGoldberg, S. N. (2001). Radiofrequency tumor ablation: principles and techniques. European Journal of Ultrasound, 13(2), 129-147. \u003cstrong\u003ehttps://doi.org/10.1016/S0929-8266(01)00044-0\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Microwave ablation, radiofrequency ablation, volume reduction rate, benign thyroid nodules","lastPublishedDoi":"10.21203/rs.3.rs-5383714/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5383714/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e to compare the two ablation techniques, we assessed 81 benign thyroid nodules of 38 cases who underwent radiofrequency ablation (RFA) and 43 cases who underwent microwave ablation (MWA) over a 12-month period. The inclusion criteria involved benign thyroid nodules with compression symptoms or cosmetic problems, cytological confirmation of benignity with no atypical cells, and case refusal or unfit for operation. No predilection for the ultrasound nature of the nodules, whether they were cystic, solid, or complex, or their size or number. radiofrequency ablation was carried out utilizing the Mygen (M-3004) radiofrequency generator from radiofrequency Medical Co., Ltd., South Korea, and MWA (Microwave Ablation) was conducted utilizing the Canyon KY2000-A MCW generator from Canyon Medical Inc.\u003c/p\u003e\n\u003cp\u003eThe clinical problems and the nodules volume have been assessed both following and prior to the surgery. Factors and complications associated with Volume Reduction Rate (VRR) have been assessed. This investigation is designed to evaluate the efficacy and safety of microwave ablation guided by ultrasound (US) versus radiofrequency ablation in the management of benign thyroid nodules.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMean VRR(volume reduction rate) of MWA group versus the RFA group at one, three, six, and twelve months were 53.1% ± 11.2% vs. 45.8% ± 13.5% (P =0.009), 67.9% ± 11.5%vs. 61.8% ± 12.8% (P = 0.027), 77.5% ± 9.7%vs. 73.4% ± 11% (P = 0.084), and 85.4% ± 7.6% vs. 83.6% ± 6.4% (P-value = 0.252), respectively.\u003c/p\u003e\n\u003cp\u003eA statistically significant variance has been discovered within the VRR among both the radiofrequency ablation group and the microwave ablation group in one and three month follow up. Additionally, all cases were able to maintain thyroid function, and both groups reported a significant reduction in symptom and cosmetic scores. Among the overall case population, one patient in the RF group had a minor burn that resolved after 1 month and transient voice changes occurred in one patient in each group that resolved after two weeks.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e Both radiofrequency ablation and microwave ablation are safe and efficient methods for managing BTNs. The MWA group showed greater volume reduction rates at the 1- and 3-month follow-ups.\u003c/p\u003e","manuscriptTitle":"Efficacy and Safety of Ultrasound Guided Microwave versus Radiofrequency Ablation of Benign Thyroid Nodules","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-26 08:53:51","doi":"10.21203/rs.3.rs-5383714/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":"8edc42d1-4a4b-41a5-9e49-ca0024cba55f","owner":[],"postedDate":"March 26th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-06-23T16:04:20+00:00","versionOfRecord":{"articleIdentity":"rs-5383714","link":"https://doi.org/10.1186/s43055-025-01503-3","journal":{"identity":"egyptian-journal-of-radiology-and-nuclear-medicine","isVorOnly":false,"title":"Egyptian Journal of Radiology and Nuclear Medicine"},"publishedOn":"2025-06-18 15:57:33","publishedOnDateReadable":"June 18th, 2025"},"versionCreatedAt":"2025-03-26 08:53:51","video":"","vorDoi":"10.1186/s43055-025-01503-3","vorDoiUrl":"https://doi.org/10.1186/s43055-025-01503-3","workflowStages":[]},"version":"v1","identity":"rs-5383714","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5383714","identity":"rs-5383714","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}