Microwave ablation for low-risk papillary thyroid microcarcinoma: efficacy, safety, and prognostic factors

Introduction

The incidence of thyroid cancer has increased significantly in China (1,2), among which papillary thyroid carcinoma (PTC) is the most common (3,4). This global trend is largely driven by the increased detection of small, indolent tumors through high-resolution ultrasound screening, leading to a significant rise in papillary thyroid microcarcinoma (PTMC) diagnoses, which now account for a substantial proportion of new cases. Some PTCs have invasive features, including lymph node and vascular invasion, and distant metastasis, with cervical lymph nodes being the most common site of metastasis (4-6). The World Health Organization defines PTMC as PTC with a maximum tumor diameter of ≤1 cm (7). The treatment of PTMC is controversial, as traditional surgery and active surveillance each have limitations (such as overtreatment, psychological stress, and the risk of tumor progression) (8). The drawbacks of surgical resection and active surveillance have prompted minimally invasive treatment techniques to gradually become a research hotspot.

Microwave ablation (MWA), as a representative technique, has been proven safe and effective in treating benign thyroid nodules, with advantages such as minimal invasiveness, good cosmetic results, rapid recovery, and little impact on thyroid function (9-11). Several studies have suggested that its efficacy in low-risk PTMC is comparable to that of surgery, with a lower complication rate (12,13), but long-term evidence still needs to be improved. In addition, the applicability of MWA for isthmic/multifocal lesions, capsule invasion, BRAF-V600E mutation, and lymph node metastasis requires further exploration (14), and its indications, factors influencing efficacy, and postoperative management strategies also need systematic optimization.

Our preliminary study (based on 1,400 cases of surgical pathology control) showed that, according to the Bethesda system criteria (15), the sensitivity of fine-needle aspiration biopsy (FNAB) combined with positive BRAF-V600E gene detection for PTMC was 98.0% (196/200), the specificity was 86.7% (13/15), and the positive predictive value was 98.9% (196/198). This result suggests that double-positive nodules highly indicate PTC. This study aimed to evaluate the efficacy and safety of MWA in the treatment of PTMC and such highly suspicious lesions, and to analyze the impact of different prognostic factors on the efficacy. We present this article in accordance with the STROBE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0036/rc).

Methods

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of The Second Affiliated Hospital of Guangxi Medical University [No. 2022-KYL (001), date: September 3, 2022]. All patients signed written informed consent and agreed to follow-up.

Patients

This retrospective study was conducted at The Second Affiliated Hospital of Guangxi Medical University from October 2022 to April 2025. A total of 107 low-risk PTMC patients with a total of 109 lesions met the inclusion criteria, including cytologically confirmed PTMC and highly suspicious PTMC with a positive BRAF-V600E mutation.

The inclusion criteria were as follows: (I) at least one pathologically confirmed PTMC (Bethesda class VI) or suspicious for PTC (Bethesda class V) with a positive BRAF-V600E mutation; (II) the maximum diameter (Dmax) of the nodule was ≤10 mm; (III) the tumor was confined to the thyroid gland without invasion of the capsule or surrounding tissues; (IV) no evidence of cervical lymph node or distant metastasis; and (V) refused surgical resection and active surveillance after full informed consent.

The exclusion criteria were as follows: (I) the Dmax of the nodule was >10 mm; (II) imaging (primarily high-resolution neck ultrasound and sulfur hexafluoride contrast-enhanced ultrasound) suggested extrathyroidal extension (ETE), characterized by signs such as the interruption of the continuous thyroid capsule echo; (III) presence of coarse calcification (maximum calcification point ≥1 mm); (IV) patients required surgical resection or active surveillance; (V) vital organ insufficiency results in intolerance to ablation surgery; (VI) unable to cooperate with the surgical operation; (VII) coagulation dysfunction or being treated with anticoagulant/antiplatelet drugs; and (VIII) contralateral vocal cord dysfunction.

All cases were discussed in a multidisciplinary team (MDT) meeting, including endocrinologists, radiologists, and surgeons, to confirm the appropriateness of MWA as a treatment strategy based on clinical, imaging, and cytological findings, as well as patient preference.

Preoperative preparation

A comprehensive collection of patients’ past medical history, allergy history, and medication history was conducted, and basic vital signs (heart rate, blood pressure, etc.) were monitored. For anticoagulant/antiplatelet drugs (such as aspirin, clopidogrel, warfarin), they need to be discontinued ≥5 days before surgery. At the same time, the surgical risks and precautions were fully informed, and relevant informed consent forms were signed.

Laboratory tests included blood routine, coagulation function, thyroid function [free triiodothyronine (FT3)/free thyroxine (FT4)/total triiodothyronine (TT3)/total thyroxine (TT4)/thyroid-stimulating hormone (TSH)], thyroid antibodies [thyroglobulin antibody (TGAb)/TSH receptor antibody (TRAb)/thyroid peroxidase antibody (TPOAb)], thyroglobulin (TG), reverse triiodothyronine (rT3), calcitonin (CT), and parathyroid hormone (PTH). Auxiliary examinations included an electrocardiogram and neck ultrasound (to evaluate the status of primary lesions and lymph nodes).

MWA procedure

All ablation procedures were performed using the Nanjing Kangyou MWA system (Nanjing, China) by senior physicians with ablation qualifications. The entire operation was conducted under ultrasound guidance and electrocardiographic monitoring: patients were placed in a supine position (with a pillow under the shoulders and neck to hyperextend the head or tilt it to the healthy side). After routine disinfection and draping, sulfur hexafluoride contrast-enhanced ultrasound was first performed to evaluate the blood supply of the nodules. Under ultrasound guidance, 2% lidocaine was used for local anesthesia of the skin and anterior thyroid capsule, and a mixture of normal saline and epinephrine (500 mL:2 mg) was injected to establish a safe isolation zone around the nodules (to protect the trachea, esophagus, nerves, and blood vessels). The 16-gauge puncture ablation needle (25–30 W) was inserted into the center of the lesion, and the ablation time and power were dynamically adjusted according to real-time ultrasound findings until the strong echo completely covered the lesion. After secondary contrast-enhanced ultrasound confirmed no echo enhancement and contrast agent perfusion, the needle was withdrawn. The puncture site was compressed for 10–20 minutes (with pressure bandaging if necessary). Postoperative monitoring was conducted for 4 hours to observe complications such as hoarseness, coughing, and neck swelling, with timely symptomatic treatment. The puncture site was kept clean and dry.

Efficacy evaluation and follow-up

Patients underwent scheduled follow-up at 1, 3, 6, 12, and 18 months post-MWA. Assessments included thyroid ultrasonography, thyroid function panels (FT3, FT4, TT3, TT4, TSH, TGAb, TRAb, TPOAb, TG, rT3, and PTH), and complication monitoring. Lesion shrinkage was quantified using the volume reduction rate (VRR), calculated as VRR = [(preoperative volume − follow-up volume)/preoperative volume] × 100%. Complete absorption was defined as a VRR of 100%. Nodule volume (V) was determined by the formula V = abc × Π/6, where a, b, and c represent the three orthogonal diameters of the nodule.

Safety was assessed by documenting all adverse events. Complications were classified according to the Society of Interventional Radiology (SIR) classification system as minor (requiring no therapy or nominal therapy) or major (requiring significant therapy, resulting in hospitalization, or causing permanent adverse sequelae or death).

Statistical analysis

Statistical analysis was performed using SPSS 24.0 software. The normality of measurement data was evaluated by the Shapiro-Wilk test. Data conforming to a normal distribution were expressed as mean ± standard deviation (SD) and compared using the paired samples t-test; data not conforming to a normal distribution were analyzed using the paired Wilcoxon signed-rank or Friedman test. Categorical data were presented as frequencies and percentages (n, %), and comparisons between groups were conducted using the Chi-squared (χ²) test or Fisher’s exact test according to applicable conditions. Logistic regression analysis was used to explore influencing factors. A P value <0.05 was considered statistically significant.

Unit of analysis: for baseline characteristics and complication analysis, the patient was used as the unit of analysis (n=107). For lesion-specific outcomes, including diameter, volume, and VRR, the lesion was used as the unit of analysis (n=109). In patients with multiple lesions (two patients with two lesions each), each lesion was analyzed independently for morphological outcomes, while patient-level outcomes (thyroid function, complications) were analyzed once per patient. Sensitivity analyses were performed to assess the impact of clustering effects in patients with multiple lesions.

Results

General information about the patients

A total of 107 patients (81 female and 26 male) with 109 low-risk PTMC lesions were included. Baseline characteristics are summarized in Table 1. The median age of the patients was 42 years, and the median body mass index (BMI) was 23.78 kg/m². According to the FNAB cytopathological results, there were 43 Bethesda class V nodules (39.4%) and 66 Bethesda class VI nodules (60.6%). The results of BRAF-V600E gene detection showed 104 mutant-type nodules (95.4%) and 3 wild-type nodules (2.8%). Among them, 43 nodules (39.4%) were Bethesda class V with positive BRAF-V600E mutation, and no positive TERT gene was detected. The median Dmax of the nodules before ablation was 6.10 mm (range, 2.40–9.80 mm), and the median preoperative volume was 69.05 mm³. The median duration of ablation was 66 seconds (range, 25–261 seconds).

Changes of thyroid nodule diameter, volume, and VRR after MWA

Follow-up after MWA showed that the median Dmax of the ablated area increased significantly to 15.20 mm at 1 month postoperatively, then gradually decreased to 11.90, 9.00, 5.00, and 4.70 mm at 3, 6, 12, and 18 months, respectively. Similarly, the median volume increased to 816.41 mm³ at 1 month postoperatively, followed by progressive reductions to 380.75, 188.50, 43.30, and 34.56 mm³ at 3, 6, 12, and 18 months, respectively. Statistical analysis revealed that both Dmax and volume at 1 month postoperatively were significantly larger than preoperative values (P<0.05). In contrast, Dmax and volume at 3, 6, and 12 months were significantly smaller than those at 1 month (P<0.05). By 12 months postoperatively, the median Dmax had decreased to 5.00 mm, which was significantly smaller than the preoperative median of 6.10 mm (P<0.05). The most rapid volume reduction occurred between 1 and 3 months postoperatively (Figure 1A,1B) (for detailed data, see Table 2).

Figure 1 Evaluation of the therapeutic effect of MWA. (A) Dmax of the ablation area, (B) ablation zone volume, (C) VRR, and (D) TSH changes. Larger data points in the scatter plots represent values from multiple patients. Dmax, maximum diameter; MWA, microwave ablation; TSH, thyroid-stimulating hormone; VRR, volume reduction rate.

As shown in Table 3, the median VRR was −895.8% at 1 month, reflecting initial edema, and improved to −495.2% at 3 months, −168.9% at 6 months, and 48.9% at 12 months. Nonparametric tests among multiple groups indicated that the increase in VRR at each time point was statistically significant (P<0.001). The VRR reached 49.20% at 18 months postoperatively, with the increasing rate slowing down over time (Figure 1C). By 18 months postoperatively, a total of 10 lesions achieved complete absorption (VRR =100%), among which 7 cases (30.4%) were absorbed within 12 months, 1 new case was added within 18 months, and another 2 cases achieved complete absorption at 24 months postoperatively.

Changes in thyroid function before and after MWA treatment

To evaluate the impact of MWA on thyroid function, we excluded patients with baseline thyroid dysfunction, those taking related medications, or those who had undergone neck surgery, ultimately including 84 patients for analysis (Table 4). The results showed that 4.76% (4/84) developed thyroid dysfunction postoperatively: subclinical hypothyroidism (2 cases, 2.38%) and subclinical hyperthyroidism (1 case, 1.19%) both recovered spontaneously within 3 months; one case of hyperthyroidism (1.19%) progressed to subclinical hyperthyroidism after 7 months of methimazole treatment and continued follow-up after drug withdrawal. Further statistical analysis revealed that MWA had minimal effect on TSH levels (r=0.0483, P>0.05; Figure 1D).

After excluding patients taking thyroid hormone-related medications, 95 patients were included in the analysis. During follow-up (pre-MWA and 1/3/6/12/18 months post-MWA), triiodothyronine (T3), thyroxine (T4), FT3, FT4, and TSH levels remained within normal reference ranges (Table 5). After statistical analysis, there was no significant difference between the above indicators at each time point before and after treatment (P>0.05).

Other complications after MWA and their outcomes

Safety assessment post-MWA revealed a minor complications rate of 6.54% (7/107) among all patients, comprising two cases of minor ablation-site swelling/pain (resolved with ice compress plus analgesics/anti-inflammatories) and one case of transient hoarseness (self-healed within 1 month). Critically, no major complications occurred—including massive hemorrhage, infection, permanent recurrent laryngeal nerve injury, or tracheal/esophageal damage—demonstrating the favorable safety profile of MWA.

Ultrasound follow-up after MWA showed that all ablated areas had no blood flow signals, and no recurrent or new lesions were found at the treatment site or in the ipsilateral/contralateral thyroid gland. During the follow-up period (1, 3, 6, and 9 months after surgery), a total of 5 cases of new cervical lymphadenopathy were detected (1, 1, 2, and 1 case at each time point, respectively), among which 1 case (detected at 3 months after surgery) shrank spontaneously during follow-up. Ultrasonic evaluation of all enlarged lymph nodes showed no malignant signs (such as unclear demarcation between cortex and medulla, disappearance of hilar structure, or abundant blood flow signals).

Analysis of influencing factors of lesion VRR after MWA

Complete absorption was defined as a VRR of 100%, with other cases classified as incomplete absorption. Among the 109 lesions, complete absorption first occurred at 12 months after MWA. Therefore, the 12-month post-procedure time point was set as the observation window for analyzing the efficacy factors of ultrasound-guided MWA in the treatment of PTMC or highly suspicious PTMC (n=23 lesions: complete absorption n=7, incomplete n=16).

Baseline characteristics and procedural data comparison (Table S1) revealed no significant intergroup differences in gender, age, BMI, comorbidities, BRAF-V600E status, nodule multiplicity, Thyroid Imaging Reporting and Data System (TI-RADS) classification, FNAB cytology, lesion location, initial Dmax/volume, ablation time per unit volume, or power (P>0.05); similarly, preoperative thyroid function indices and hormone levels showed no significant differences between the two groups (all P>0.05). TRAb was normal in 1/1 and absent in 16/6; TPOAb was normal in 14/6 and elevated in 3/1 (incomplete absorption/complete absorption).

Lesions were stratified into three groups by preoperative Dmax tertiles: Group A, Dmax ≤5.3 mm; Group B, 5.3< Dmax ≤6.7 mm; Group C, Dmax >6.7 mm. As shown in Table 6, significant differences in VRR were observed among groups at 1-month post-MWA (P<0.05). Pairwise comparisons revealed significantly higher VRR in Group C versus Group A (P<0.05), whereas Group B showed no statistical difference from Group A or C. During 3-, 6-, and 12-month follow-up, VRR did not differ significantly among groups (P>0.05).

Discussion

With improved ultrasound resolution and widespread adoption of FNAB, the detection rate of PTMC (≤10 mm) has risen substantially (16), prompting broad clinical interest in its treatment indications and strategies. Most PTMCs, the predominant pathological subtype, exhibit indolent behavior and low mortality. Current guidelines recommend active surveillance for low-risk cases (17-19). However, concerns regarding disease progression risk and the psychological burden of “living with cancer” lead patients to prefer active interventions. Although surgery remains the first-line treatment for PTMC, complications like permanent hypothyroidism and recurrent laryngeal nerve paralysis significantly impair quality of life, necessitating careful risk-benefit assessment. MWA, offering minimal invasiveness, quick recovery, and thyroid function preservation, has shown proven efficacy for benign nodules, but its role in PTC remains debated (20). When compared to other thermal techniques such as radiofrequency ablation (RFA) and laser ablation (LA), MWA is characterized by higher thermal efficiency and a reduced heat-sink effect, potentially allowing for more complete and rapid destruction of malignant tissue. Although RFA and LA currently maintain a more established presence in the United States (U.S.) clinical guidelines, there is growing international interest in MWA due to its ability to generate larger, more predictable ablation zones. Its relatively limited use in the U.S. at present may be attributed to differences in device availability rather than therapeutic inferiority. This study, based on 18-month follow-up data, further evaluates the safety and efficacy of ultrasound-guided MWA for PTMC and highly suspicious PTMC, supporting clinical decision-making.

The ablation zone in this study showed a distinct pattern of initial enlargement followed by gradual shrinkage. This evolution reflects the typical healing response after thermal ablation. Immediately after treatment, a zone of coagulative necrosis is intentionally created beyond the tumor margin to ensure complete coverage. In this study, technical success and treatment completeness were strictly confirmed using intraoperative contrast-enhanced ultrasound, ensuring no contrast agent perfusion remained within the ablation zone. This image-guided protocol provides immediate reassurance of tumor inactivation, although pathological confirmation via core needle biopsy (CNB) was not routinely performed to maintain the study’s minimally invasive nature. During the first month, the area may transiently expand due to inflammatory response and tissue edema (21,22). Afterward, a resorption and remodeling phase occurs, characterized by liquefaction and absorption of necrotic tissue and subsequent fibrosis. The most rapid volume reduction was observed after three months, with a median VRR of 48.9% at 12 months, after which the ablation zone stabilized as a fibrotic scar. Similar temporal changes have been reported in other studies, showing early volume increase followed by progressive contraction (23-25). Their study demonstrated significant volume decrease initiation at 3 months post-MWA, with maximal reduction during 3–6 months, suggesting accelerated tissue absorption at this phase and further validating its importance in outcome evaluation.

Regarding tumor control, throughout the follow-up period of this study (up to 18 months), no blood flow signals were detected in the ablated areas, nor was in situ recurrence or the emergence of new lesions observed. Only five cases of new cervical lymphadenopathy were detected, all of which lacked malignant features, suggesting that MWA could effectively inactivate target lesions and control local tumor progression. This finding is consistent with those of multiple studies investigating thermal ablation for low-risk PTMC. For example, Cho et al. reported a 100% recurrence-free survival rate at 1 year after thermal ablation, confirming the efficacy of minimally invasive techniques in controlling low-risk PTMC oncologically (23). Furthermore, complete absorption (VRR =100%) was achieved in seven lesions by 12 months, and the cumulative number increased to eight at 18 months. Despite the relatively low rate, this outcome indicates the potential for MWA to eliminate some lesions, thereby providing a possibility of “minimally invasive cure”.

Patient safety is a core consideration in the clinical application of MWA. In this study, the overall incidence of adverse events was 6.54%. All adverse events were mild symptoms (such as local swelling and pain, transient hoarseness), with no occurrence of severe complications like massive hemorrhage or permanent recurrent laryngeal nerve injury. This incidence is significantly lower than the complication rates associated with traditional surgery (26,27). This favorable safety profile stems from ultrasound-guided precision: the establishment of a protective saline-epinephrine hydro dissection zone to shield surrounding tissues, and the dynamic adjustment of ablation parameters to avoid energy overflow. These measures demonstrate the technical controllability and safety of MWA in anatomically complex regions. Regarding functional preservation, thyroid function indices remained stable within normal ranges throughout the follow-up (28). Interestingly, our analysis of prognostic factors showed that complete lesion absorption was not significantly associated with initial diameter or volume. This finding contrasts with the common hypothesis that smaller lesions undergo faster absorption. This discrepancy may stem from our limited sample size or the unique histological characteristics of PTMC, which require longer observation to fully capture the absorption trajectory (29,30), which may be related to the following factors: first, the sample size is small, resulting in limited statistical power; second, the histological characteristics of PTMC may affect the absorption rate, but relevant pathological details were not included in this study; third, complete absorption is a gradual process, and the 12-month observation window is insufficient, so it is necessary to extend the observation window to capture a more complete absorption pattern.

From a molecular biology perspective, the BRAF-V600E mutation rate in this study was as high as 95.4% (104/109), but no association with absorption efficiency was found. It is noteworthy that the BRAF-V600E mutation rate in this cohort (95.4%) was substantially higher than the 60–65% typically reported in U.S. populations. This elevation is primarily attributable to our inclusion criteria, which specifically recruited patients with “highly suspicious” nodules (Bethesda class V) that were confirmed positive for BRAF-V600E to ensure diagnostic accuracy before ablation. Consequently, our findings emphasize that MWA remains oncologically effective even in this molecularly high-risk subgroup. Although BRAF mutations often indicate invasive potential (31), no recurrence was observed in the patients in this group. This may be because MWA directly inactivates tumor cells through physical thermal damage, which is not affected by their molecular subtypes. This supports the view that “low-risk PTMC is suitable for ablation even with BRAF mutations” (32), providing new insights into the minimally invasive treatment of BRAF-mutant PTMC. However, it should be noted that this study excluded high-risk cases with capsule invasion or metastasis, so the results are only applicable to low-risk PTMC.

This study acknowledges several limitations: the maximum 18-month follow-up period remains relatively short given PTMC’s indolent nature, requiring extended surveillance to 5–10 years for conclusive recurrence risk assessment; the absence of comparative cohorts (e.g., surgery or active surveillance) precludes direct evaluation of MWA’s relative efficacy, cost-effectiveness, and quality-of-life advantages; and the constrained sample size (n=107), particularly the limited complete absorption cases, potentially obscures significant predictors of treatment response, necessitating large-scale multicenter validation.

Conclusions

The short-term data of this study suggest that MWA is a promising minimally invasive option for low-risk PTMC. While short-term outcomes are encouraging, the current follow-up period remains limited. Further prospective, multicenter studies with 5–10 years of follow-up are necessary to establish its long-term tumor control and status as a comparable alternative to standard surgical interventions.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0036/rc

Data Sharing Statement: Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0036/dss

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0036/prf

Funding: This study was supported by the National Natural Science Foundation of China (No. 82360160) and the Self-Funded Scientific Research Project of the Health Commission of Guangxi (No. Z-A20250548).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0036/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Ethics Committee of The Second Affiliated Hospital of Guangxi Medical University [No. 2022-KYL (001), date: September 3, 2022]. All patients signed written informed consent.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Han B, Zheng R, Zeng H, et al. Cancer incidence and mortality in China, 2022. J Natl Cancer Cent 2024;4:47-53. [Crossref] [PubMed]
2. Li M, Hu M, Jiang L, et al. Trends in Cancer Incidence and Potential Associated Factors in China. JAMA Netw Open 2024;7:e2440381. [Crossref] [PubMed]
3. Cabanillas ME, McFadden DG, Durante C. Thyroid cancer. Lancet 2016;388:2783-95. [Crossref] [PubMed]
4. Almeida LS, Santos A, Assumpção L, et al. 68 Ga-DOTATATE PET/CT Versus 18 F-FDG PET/CT in TENIS Syndrome: A Head-to-Head Comparison With Elevated and Suppressed TSH Levels in Papillary Thyroid Carcinoma-A Pilot Study. Clin Nucl Med 2024;49:1004-13. [Crossref] [PubMed]
5. Al-Qurayshi Z, Nilubol N, Tufano RP, et al. Wolf in Sheep's Clothing: Papillary Thyroid Microcarcinoma in the US. J Am Coll Surg 2020;230:484-91. [Crossref] [PubMed]
6. Ahn HS, Welch HG. South Korea's Thyroid-Cancer "Epidemic"--Turning the Tide. N Engl J Med 2015;373:2389-90. [Crossref] [PubMed]
7. Lam AK. Histopathological Assessment for Papillary Thyroid Carcinoma. Methods Mol Biol 2022;2534:93-108. [Crossref] [PubMed]
8. Yoshida Y, Horiuchi K, Okamoto T. Patients' View on the Management of Papillary Thyroid Microcarcinoma: Active Surveillance or Surgery. Thyroid 2020;30:681-7. [Crossref] [PubMed]
9. Crespo Vallejo E, Hermosin A, Gargallo M, et al. Multiple overlapping microwave ablation in benign thyroid nodule: a single-center 24-month study. Eur Thyroid J 2023;12:e220175. [Crossref] [PubMed]
10. Lim HK, Lee JH, Ha EJ, et al. Radiofrequency ablation of benign non-functioning thyroid nodules: 4-year follow-up results for 111 patients. Eur Radiol 2013;23:1044-9. [Crossref] [PubMed]
11. Papini E, Monpeyssen H, Frasoldati A, et al. 2020 European Thyroid Association Clinical Practice Guideline for the Use of Image-Guided Ablation in Benign Thyroid Nodules. Eur Thyroid J 2020;9:172-85. [Crossref] [PubMed]
12. Yan L, Liu Y, Li W, et al. Long-term Outcomes of Ultrasound-guided Thermal Ablation for the Treatment of Solitary Low-risk Papillary Thyroid Microcarcinoma: A Multicenter Retrospective Study. Ann Surg 2023;277:846-53. [Crossref] [PubMed]
13. Yu XY, Zhou HD, Wei Y, et al. Preliminary Study of Microwave Ablation for Multifocal Papillary Thyroid Microcarcinoma in Nonoperative Candidates. J Vasc Interv Radiol 2023;34:999-1006. [Crossref] [PubMed]
14. Ultrasound Society of Physicians of Chinese Medical Doctor Association. Expert consensus on indications for thermal ablation therapy of papillary thyroid microcarcinoma. Chinese Journal of Medical Ultrasound 2019;16:571-4. (Electronic Edition).
15. Ali SZ, Baloch ZW, Cochand-Priollet B, et al. The 2023 Bethesda System for Reporting Thyroid Cytopathology. Thyroid 2023;33:1039-44. [Crossref] [PubMed]
16. Ito Y, Miyauchi A, Oda H. Low-risk papillary microcarcinoma of the thyroid: A review of active surveillance trials. Eur J Surg Oncol 2018;44:307-15. [Crossref] [PubMed]
17. Horiguchi K, Yoshida Y, Iwaku K, et al. Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults. Endocr J 2021;68:763-80. [Crossref] [PubMed]
18. Sugitani I, Ito Y, Takeuchi D, et al. Indications and Strategy for Active Surveillance of Adult Low-Risk Papillary Thyroid Microcarcinoma: Consensus Statements from the Japan Association of Endocrine Surgery Task Force on Management for Papillary Thyroid Microcarcinoma. Thyroid 2021;31:183-92. [Crossref] [PubMed]
19. Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid 2016;26:1-133. [Crossref] [PubMed]
20. vanSonnenberg E, Simeone JF. Microwave Ablation versus Surgery for Papillary Thyroid Carcinoma: More Therapeutic Options, More Controversies. Radiology 2022;304:714-5. [Crossref] [PubMed]
21. Li S, Yu MA, Zhao ZL, et al. Changes in thyroid function after thermal ablation of thyroid nodules. Front Endocrinol (Lausanne) 2025;16:1557725. [Crossref] [PubMed]
22. Zu Y, Liu Y, Zhao J, et al. A cohort study of microwave ablation and surgery for low-risk papillary thyroid microcarcinoma. Int J Hyperthermia 2021;38:1548-57. [Crossref] [PubMed]
23. Cho SJ, Baek JH, Chung SR, et al. Thermal Ablation for Small Papillary Thyroid Cancer: A Systematic Review. Thyroid 2019;29:1774-83. [Crossref] [PubMed]
24. Zhou XY, Yu XY, Wei Y, et al. Efficacy and safety of microwave ablation for treatment of follicular thyroid neoplasms: a preliminary study. Int J Hyperthermia 2024;41:2398558. [Crossref] [PubMed]
25. Negro R, Greco G, Deandrea M, et al. Twelve-Month Volume Reduction Ratio Predicts Regrowth and Time to Regrowth in Thyroid Nodules Submitted to Laser Ablation: A 5-Year Follow-Up Retrospective Study. Korean J Radiol 2020;21:764-72. [Crossref] [PubMed]
26. Li Y, Liu Z, Song Z, et al. Comparison of the endoscopic thyroidectomy via areola approach and open thyroidectomy: A propensity score matched cohort study of 302 patients in the treatment of papillary thyroid non-microcarcinoma. Front Oncol 2023;13:1081835. [Crossref] [PubMed]
27. Kwon H, Jeon MJ, Kim WG, et al. A comparison of lobectomy and total thyroidectomy in patients with papillary thyroid microcarcinoma: a retrospective individual risk factor-matched cohort study. Eur J Endocrinol 2017;176:371-8. [Crossref] [PubMed]
28. Han ZY, Dou JP, Zheng L, et al. Safety and efficacy of microwave ablation for the treatment of low-risk papillary thyroid microcarcinoma: a prospective multicenter study. Eur Radiol 2023;33:7942-51. [Crossref] [PubMed]
29. Wang L, Zheng S. Advances in influence factors of ultrasound-guided percutaneous thermal ablations for benign thyroid nodules: A review. Medicine (Baltimore) 2024;103:e39218. [Crossref] [PubMed]
30. Fu QQ, Kang S, Wu CP, et al. A study on the efficacy of microwave ablation for benign thyroid nodules and related influencing factors. Int J Hyperthermia 2021;38:1469-75. [Crossref] [PubMed]
31. Lai Y, Gu Y, Yu M, et al. Younger Than 55 Years Old and BRAF V600E Mutation are Risk Factors for Lymph Node Metastasis in Papillary Thyroid Carcinomas ≤1.0 cm but Not in >1.0 cm. Int J Gen Med 2023;16:1403-14. [Crossref] [PubMed]
32. Lin Y, Wu ZR, Shi YP, et al. Radiofrequency Ablation of Unifocal Papillary Thyroid Microcarcinoma With BRAF V600E Mutation. J Clin Endocrinol Metab 2023;108:e1298-305. [Crossref] [PubMed]