A cohort study of microwave ablation and surgery for low-risk papillary thyroid microcarcinoma

Thermal Ablation for Papillary Thyroid Carcinoma

Importance

Image-guided thermal ablation has been administered for patients with T1N0M0 papillary thyroid carcinoma (PTC) who elect to not undergo surgery or receive active surveillance. Considering the indolent nature of PTC, long-term outcomes of ablation are needed.

Objective

To investigate l0-year outcomes of thermal ablation in treating T1N0M0 PTC.

Design, Setting, and Participants

This multicenter study was conducted at 4 university-affiliated hospitals in China and included 179 consecutive patients with T1N0M0 PTC (median [IQR] volume, 88.0 [163.2] mm3) who underwent thermal ablation between June 2010 and March 2014. Patients who were ineligible to undergo surgery or elected not to were included, and patients had PTC tumors that were smaller than 20 mm as confirmed by biopsy; no clinical or imaging evidence of extrathyroidal extension, lymph node metastasis (LNM), or distant metastasis; and no history of neck irradiation.

Main Outcomes and Measures

The primary outcomes were disease progression (LNM, newly developed tumors, persistent tumors, and distant metastasis) and disease-free survival (DFS). Secondary outcomes were technical success, volume reduction rate, tumor disappearance, complications, and delayed surgery. DFS was calculated using a Kaplan-Meier analysis.

Results

Among the 179 patients, the mean (SD) age was 45.8 (12.7) years, and 118 (65.9%) were female. During a mean (SD) follow-up period of 120.8 (10.8) months, disease progression was found in 11 of 179 patients (6.1%), including LNM in 4 patients (2.2%), newly developed tumors in 6 patients (3.3%), and persistent tumor in 1 patient (0.6%). The 10-year DFS was 93.9%. The technical success, median volume reduction rate, and tumor disappearance rate was 100%, 100%, and 97.2%, respectively. The magnitude of the disease progression (6.1% vs 7.1%; difference, 1.0%; 95% CI, -6.5% to 25.6%) and DFS (93.9% vs 92.9%; difference, 1.0%, 95% CI, -6.5% to 25.6%) between patients with T1a and T1b tumors was small. The difference in the rate of tumor disappearance between T1a and T1b tumors was large (99.4% vs 71.4%; difference, 28.0%; 95% CI, 10.9%-54.0%). One patient experienced transient voice hoarseness (0.6%). Because of anxiety, 1 patient underwent delayed surgery (0.6%).

Conclusions and Relevance

The results of this 10-year multicenter cohort study suggest that thermal ablation is an effective and safe alternative for patients with T1N0M0 PTC who do not undergo surgery or receive active surveillance. For safe and effective treatment, accurate radiologic evaluation, an understanding of ablation techniques, and experienced physicians are recommended.

Comparison of Ultrasound-Guided Percutaneous Microwave Ablation and Conventional Thyroidectomy in the Treatment of Papillary Thyroid Microcarcinoma: Meta-Analysis

Purpose: To perform a meta-analysis of clinical trials comparing percutaneous microwave ablation (PMWA) guided by ultrasound with conventional thyroidectomy for the management of papillary thyroid microcarcinoma (PTMC), analyzing feasibility, safety, and long-term efficacy, and to provide clinical guidance for the treatment selection of PTMC. Methods: Embase, PubMed, Cochrane Library, Web of Science, CNKI, VIP Database, and Wanfang Database were systematically searched to identify clinical studies of PMWA or thyroidectomy for PTMC up to December 2023. The relevant data from the articles were extracted, and the data analysis was performed using RevMan 5.4 software. Results: A total of 442 articles were identified and subsequently screened based on the inclusion and exclusion criteria, 9 clinical studies involving a total of 1577 patients were included, with 788 patients in the PMWA group and 789 patients in the surgery group. Following data extraction and statistical analysis, in comparison to the surgery group, the PMWA group had shorter operation time [mean differences (MD) = -36.36; 95% CI -55.66 to -17.06; P = .0002], shorter hospital stay (MD = -3.93; 95% CI -5.55 to -2.30; P < .00001), less intraoperative bleeding (MD = -21.25; 95% CI -27.36 to -15.15; P < .00001), and lower hospital costs (MD = -1.00; 95% CI -1.33 to -0.66; P < .00001), all with statistical significance. The comparison of postoperative complications revealed a lower incidence of complications in the PMWA group compared to the surgery group [relative risk (RR) = 0.29; 95% CI 0.21 to 0.40; P < .00001], with statistical significance. Thyroid-related hormone analysis showed that the free triiodothyronine (MD = 0.61; 95% CI 0.33 to 0.90; P < .00001) and free thyroxine (MD = 1.81; 95% CI 0.94 to 2.68; P < .0001) levels in the PMWA group were higher than those in the traditional surgery group, while the levels of thyroid-stimulating hormone were lower than those in the traditional surgery group (MD = -7.63; 95% CI -10.25 to -5.01; P < .00001), with statistically significant differences, indicating that PMWA had a smaller impact on thyroid function. In 2 studies, there were no statistically significant disparities in postoperative recurrence or lymph node metastasis (LNM) between the 2 cohorts (RR = 0.70; 95% CI 0.33 to 1.50; P = .36). There were no statistically significant differences in physiological health score between different groups and different time points before and after treatment (P > .05); However, the mental component score and the total score of the Medical Outcomes Study (MOS) item short-form health survey were significantly elevated in the ablation group compared to the excision group post-treatment (P < .05). Conclusion: For patients with low-risk PTMC with definitive diagnosis and precise risk stratification, PMWA can be selected. PMWA treatment for patients with PTMC is comparable to conventional surgical treatment and has the advantages of minimal trauma, rapid recovery, no scarring, and fewer complications, which are superior to open surgery to a certain extent. For patients with ambiguous preoperative diagnosis and uncertainty regarding LNM status, surgical intervention is the optimal choice.

Long-term comparison of image-guided thermal ablation vs. lobectomy for solitary papillary thyroid microcarcinoma: a multi-center retrospective cohort study

BACKGROUND

Image-guided thermal ablation has been applied in patients with papillary thyroid microcarcinoma (PTMC) who refuse surgery or active surveillance. However, evidence to support ablation is limited by single-center designs and a lack of long-term data. The purpose of this study was to compare long-term outcomes between ablation and lobectomy for patients with solitary PTMC.

MATERIALS AND METHODS

This multi-center retrospective study included 1021 consecutive patients with solitary PTMC who underwent ablation ( n =444) or lobectomy ( n =577) at the four university-affiliated hospitals. The primary outcomes were disease progression [lymph node metastasis (LNM), recurrent tumors, persistent tumors and distant metastasis] and disease-free survival (DFS). Secondary outcomes were complications, hospitalization, procedure time, estimated blood loss and cost. The two groups were compared using propensity score matching.

RESULTS

After matching, no significant differences were observed in disease progression (4.7% vs. 3.4%, P =0.307), LNM (1.6% vs. 1.6%, P =1.000), recurrent tumors (2.9% vs. 1.8%, P =0.269), persistent tumors(0.2% vs. 0%, P =0.317) and DFS (95.5% vs. 97.1%, P =0.246) between the ablation and lobectomy groups during the median follow-up of 96.5 months. The ablation group had significantly lower complication rates (0.7% vs. 5.2%, P <0.001), shorter post-treatment hospitalization {median [interquartile range (IQR)], 0 vs. 4.0 [3.0] days, P <0.001}, shorter procedure time [8.5 (2.8) vs. 90.0 (43.8) min, P <0.001], reduced estimated blood loss [0 vs. 20.0 (10.0) ml, P <0.001], and lower cost [$1873.2 (254.0) vs. $2292.9 (797.8), P <0.001] than the lobectomy group.

CONCLUSIONS

This study revealed comparable disease progression and survival outcomes between ablation and lobectomy for solitary PTMC. Imaged-guided thermal ablation could be effective and safe alternatives to lobectomy for properly selected patients with PTMC.

Efficacy and safety of thermal ablation modalities for the treatment of papillary thyroid microcarcinoma: Systematic Review and network meta-analysis

Background

Thermal ablation (TA) modalities such as radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) have been widely used in the treatment of papillary thyroid microcarcinoma (PTMC) patients. Based on previous small-sample meta-analyses, this network meta was designed to further compare the efficacy and safety of these thermal ablation methods in PTMC patients.

Methods

China National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Embase, and the Cochrane Library databases were searched to retrieve relevant studies published before May 2022. The efficacy outcomes was recurrence and lymph node metastasis (LNM), the safety outcome included operation time, intra-operative blood loss, hospital stays and complications. The Newcastle-Ottawa Scale (NOS) was selected for the risk of bias assessment. Stata 14.0 was used for statistical analysis.

Results

Twenty-nine articles were included. Based on as least 6 months follow up, our analysis discovered no significant statistical differences in all efficacy and safety outcomes between MWA, RFA, and LA groups. Moreover, three TA treatments all produced significant least operation time, hospital stays, and complications than surgery group. Additionally, our study found that RFA showed relatively less complications, LNM, operation time and intra-operative blood loss, compared with other TA treatments. MWA indicated the lowest probability of recurrence, LA showed the longest hospital stays.

Conclusions

MWA, RFA, and LA are all effective treatment strategies for patients with PTMC, but could not completely replace conventional surgical treatment.

Ultrasound-guided percutaneous thermal ablation of parotid tumors: experience from two-centers

Objective: To evaluate the efficacy and feasibility of ultrasound-guided percutaneous thermal ablation (TA) for treating benign parotid tumors.Methods: Patients with benign parotid tumors who underwent ultrasound-guided microwave ablation (MWA) or radiofrequency ablation (RFA) between January 2020 and March 2023 were included in this retrospective study. Change in tumor size (maximum diameter, tumor volume(V), volume reduction rate (VRR)) and cosmetic score (CS) were evaluated during a one-year follow-up period. We also recorded the incidence of any complications associated with TA.Results: A total of 23 patients (13 males and 10 females; median age 65 years, range 5-91 years) were included. The mean VRR at 1, 3, 6, and 12 months after TA was 37.03%±10.23%, 56.52%±8.76%, 82.28%±7.89%, and 89.39%±6.45%, respectively. Mean CS also changed from 3.39 ± 0.66 to 1.75 ± 0.93 (p < 0.001) by the end of follow-up time. Subgroup analysis showed that tumors with smaller initial maximum diameter had a faster CS reduction rate than those with larger initial diameter. The incidence of facial nerve dysfunction was 8.70%.Conclusion: Ultrasound-guided percutaneous TA is an effective and safe treatment option for patients with benign parotid tumors.

Efficacy and safety of ultrasound-guided radiofrequency, microwave and laser ablation for the treatment of T1N0M0 papillary thyroid carcinoma on a large scale: a systematic review and meta-analysis

BACKGROUND

To analyze the efficacy and safety of radiofrequency ablation (RFA), microwave ablation (MWA) and laser ablation (LA) in T1N0M0 papillary thyroid carcinoma (PTC) patients by evaluating data on several outcomes on a large scale.

MATERIALS AND METHODS

Literature searches were conducted in PUBMED, EMBASE and the Cochrane Library for studies of thermal ablation (TA) for treating T1N0M0 PTC. Data on the volume reduction rate (VRR) at the 12-month follow-up and final follow-up, complete disappearance rate, local recurrence rate, lymph node metastasis rate, and complication rate of RFA, MWA and LA were evaluated separately. RFA effects were compared between T1aN0M0 and T1bN0M0 patients.

RESULTS

A total of 36 eligible studies were included. RFA presented superior efficacy than MWA in 12-month VRR. At the final follow-up, the difference was slight in subgroups, showing a significant reduction. The complete disappearance rate of LA (93.00%) was higher than that of RFA (81.00%) and MWA (71.00%). Additionally, the local recurrence rate pooled proportions of MWA and RFA were both 2.00%, lower than that of the LA group (3.00%). There was no event of distant metastasis. The lymph node metastasis rates were similar, as RFA (1.00%) had the lowest. For minor complication rates, the pooled proportions of RFA (3.00%) were smaller than those of LA (6.00%) and MWA (13.00%). T1aN0M0 lesions presented with better outcomes than T1bN0M0 lesions.

CONCLUSION

RFA, MWA and LA were reliable in curing PTC, and RFA presented advantages in most outcomes. T1aN0M0 patients may experience fewer side effects than T1bN0M0 patients.

Safety and efficacy of microwave ablation for the treatment of low-risk papillary thyroid microcarcinoma: a prospective multicenter study

OBJECTIVES

To assess the safety and efficacy of ultrasound-guided thermal ablation for low-risk papillary thyroid microcarcinoma (PTMC) via a prospective multicenter study.

METHODS

From January 2017 through June 2021, low-risk PTMC patients were screened. The management details of active surveillance (AS), surgery, and thermal ablation were discussed. Among patients who accepted thermal ablation, microwave ablation (MWA) was performed. The main outcome was disease-free survival (DFS). The secondary outcomes were tumor size and volume changes, local tumor progression (LTP), lymph node metastasis (LNM), and complication rate.

RESULTS

A total of 1278 patients were included in the study. The operation time of ablation was 30.21 ± 5.14 min with local anesthesia. The mean follow-up time was 34.57 ± 28.98 months. Six patients exhibited LTP at 36 months, of whom 5 patients underwent a second ablation, and 1 patient received surgery. The central LNM rate was 0.39% at 6 months, 0.63% at 12 months, and 0.78% at 36 months. Of the 10 patients with central LNM at 36 months, 5 patients chose ablation, 3 patients chose surgery and the other 2 patients chose AS. The overall complication rate was 1.41%, and 1.10% of patients developed hoarseness of the voice. All of the patients recovered within 6 months.

CONCLUSIONS

Thermal ablation of low-risk PTMC was observed to be safe and efficacious with few minor complications. This technique may help to bridge the gap between surgery and AS as treatment options for patients wishing to have their PTMC managed in a minimally invasive manner.

CLINICAL RELEVANCE STATEMENT

This study proved that microwave ablation is a safe and effective treatment method for papillary thyroid microcarcinoma.

KEY POINTS

Percutaneous US-guided microwave ablation of papillary thyroid microcarcinoma is a very minimally invasive treatment under local anesthesia during a short time period. The local tumor progression and complication rate of microwave ablation in the treatment of papillary thyroid microcarcinoma are very low.

Effectiveness and Safety of Percutaneous Treatment in Lesions Suggestive of Thyroid Cancer (Bethesda V and VI-T1aN0M0) Compared to Surgical Treatment: Systematic Review and Meta-Analysis

INTRODUCTION

Thyroid nodules are common entities, with 5% malignancy. Differentiated thyroid cancer represents 90% of thyroid malignancies, with papillary carcinoma being the most common. Management is generally surgical; among its complications are injury to the recurrent laryngeal and superior laryngeal nerve, causing hoarseness, postsurgical hypoparathyroidism, hypothyroidism, and pain. Other noninvasive percutaneous interventions of thermal ablation such as microwave, radiofrequency, or laser incur lower costs and could be an option for treatment.

OBJECTIVE

To determine the effectiveness and safety of thermal ablation in lesions suspected of thyroid cancer (Bethesda V and VI/T1aN0M0) compared to surgical treatment.

METHODS

Systematic review/meta-analysis of observational studies and clinical trials. Database search includes MEDLINE/PUBMED, Embase, Scopus, Scielo, and BVS/LILACS. Studies on patients over 18 years of age with lesions suspicious of thyroid cancer were included.

RESULTS

A total of 10 studies were obtained, with 2939 patients: 1468 subjected to thermal ablation and 1471 to surgery. Regarding effectiveness, no differences were found in local recurrence [relative risk (RR) 1.17 (95% CI 0.69-1.99)] and cervical lymph node metastasis [RR 0.76 (95% CI 0.43-1.36)]. Regarding safety, infection [RR 0.29 (95% CI 0.05-1.74)], hematoma [RR 0.57 (95% CI 0.17-1.94)], and transient hoarseness [RR 0.77 (95% CI 0.39-1.51)] were evaluated, without difference. However, permanent hoarseness had significant differences in favor of thermal ablation [RR 0.29 (95% CI 0.11-0.75)].

CONCLUSIONS

Thermal ablation for the treatment of T1aN0M0 papillary thyroid carcinoma is equally effective when compared to surgical techniques and offers a better safety profile, particularly in permanent hoarseness.

Important parameters should be paid attention in PTMC radiofrequency ablation

In order to provide clinical references for the RFA procedure and to study the pivotal factors affecting the recovery time of radiofrequency ablation (RFA) in patients with papillary thyroid microcarcinoma (PTMC), 176 patients with low-risk intrathyroidal PTMC were included in this research. We randomly divided the whole cohort into training and test groups at a ratio of 7:3. The two-sample t-test was used to detect differences between the two groups. Least absolute shrinkage and selection operator (LASSO) regression was used to select the best predictor variables for predicting the status of RFA zone. Multiple test methods were used to ensure the scientific nature and accuracy of the Cox proportional hazards model. We tested the performance for the parameters and revealed the best cut-off value of each variable by the ROC curve and log-rank tests. The results showed patients aged above 49 years old, with RFA energy above 2800 J, the average diameter of the original tumour above 0.6 cm, or the average diameter of ablation zone at 1 month after RFA above 1.1 cm are risk factors for RFA zone delayed healing.

Latest evidence of microwave ablation for papillary thyroid microcarcinoma compared with surgery: A systematic review and meta-analysis

Background

The most typical thyroid gland malignant lesion is papillary thyroid cancer (PTC). In many nations, the prevalence of thyroid cancer (TC) is rising, particularly papillary thyroid microcarcinoma (PTMC). Microwave ablation (MWA) has been gradually carried out in some patients with benign thyroid nodules, some low-risk PTMC, and metastatic lymph nodes in the neck. The role and safety of MWA remain controversial topics. So we conducted this study to provide the latest evidence of MWA for PTMC compared with surgery.

Methods

Patients' postoperative outcomes (duration of hospital stay and hospitalization expenditures), intraoperative outcomes (surgery time, blood loss, and incision size), and follow-up outcomes were all examined (complication rate, recurrence rate, and lymph node metastasis). The effectiveness and safety of MWA versus surgery for PTMC patients were compared using the weighted mean difference (WMD) and odds ratio (OR).

Results

In total, we included 7 articles (7 trial comparisons) which contained 1, 567 PTMC patients. The results showed that MWA had significant advantages in operative time (WMD = -53.47, 95% CI: -67.62 to -39.32), postoperative hospital stay (WMD =-4.59, 95% CI: -6.40 to -2.77), hospitalization costs (WMD= -70.06, 95% CI: -90.93 to -49.19), blood loss (WMD =-28.07, 95% CI: -33.77 to -22.38), incisions size (WMD =-59.69, 95% CI: -67.79 to -51.59), and complication rates (OR = 0.28; 95% CI: 0.18 to 0.42) compared with surgery. It also showed that recurrence rates and risk of lymph node metastasis are similar to surgery.

Conclusions

For PTMC patients, MWA could be an efficient, safe, and affordable therapy.

Safety and efficacy of microwave ablation for abdominal wall endometriosis: A retrospective study

Objectives

This retrospective study aimed to evaluate the safety and feasibility of ultrasound-guided microwave ablation in the treatment of abdominal wall endometriosis (AWE).

Background

AWE is a rare form of endometriosis that often results in cyclic abdominal pain. The current treatment algorithm for AWE is not well established. Microwave ablation technology is a promising new thermal ablation technique for treating AWE.

Methods

This was a retrospective study of nine women with pathologically proven endometriosis of the abdominal wall. All patients were treated with ultrasound-guided microwave ablation. Grey-scale and color Doppler flow ultrasonography, contrast-enhanced ultrasonography, and MRI were used to observe the lesions before and after treatment. The complications, pain relief, AWE lesion volume, and volume reduction rate were recorded 12 months after treatment to evaluate the treatment efficacy. Complications were classified according to the Common Terminology Criteria for Adverse Events and the Society of Interventional Radiology classification system.

Results

Contrast-enhanced ultrasound showed that all lesions underwent successful treatment with microwave ablation. The average initial nodule volume was 7.11 ± 5.75 cm³, which decreased significantly to 1.85 ± 1.02 cm³ at the 12-month follow-up with a mean volume reduction rate of 68.77 ± 12.50%. Periodic abdominal incision pain disappeared at 1 month after treatment in all nine patients. The adverse events and complications were Common Terminology Criteria for Adverse Events grade 1 or Society of Interventional Radiology classification grade A.

Conclusions

Ultrasound-guided microwave ablation is a safe and effective technique for the treatment of AWE, and further study is warranted.

A comparative study of quality of life in patients with papillary thyroid carcinoma undergoing microwave ablation vs. Total thyroidectomy

OBJECTIVE

To compare the health-related quality of life (HRQoL) of patients with T1N0M0 papillary thyroid carcinoma (PTC) who underwent microwave ablation (MWA) and those who underwent total thyroidectomy (TT).

MATERIALS AND METHODS

From February 2018 to February 2022, 180 T1N0M0 PTC patients were enrolled in present study, including 90 in the MWA group and 90 in the TT group, respectively. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and Thyroid Cancer-Specific Quality of Life Questionnaire (THYCA-QoL) were completed by patients to evaluate their HRQoL scores.

RESULTS

According to the results of the EORTC-QLQ-C30, there was a significant difference in the scores of global health, physical, emotional, etc. between the two groups, which indicated that the quality of life in these items in the MWA group was better than those in the TT group (all p < 0.05). According to the results of the THYCA-QoL, all items had significant differences between the two groups except for headache, which demonstrated the thyroid-specific quality of life was higher in the MWA group than in the TT group (all p < 0.05).

CONCLUSION

Ultrasound (US)-guided MWA offers a significant advantage in HRQoL over TT in T1N0M0 PTC patients, which provides an important reference for MWA as an alternative strategy to TT.

Nomogram for predicting central lymph node metastasis in T1-T2 papillary thyroid cancer with no lateral lymph node metastasis

OBJECTIVE

Whether routine central lymph node dissection (CLND) is necessary for T1-T2 papillary thyroid carcinoma (PTC) patients without certain lateral lymph node metastases (LLNM) remains controversial. This study aims to construct a nomogram that predicts central lymph node metastasis (CLNM) for T1-T2 PTC patients without LLNM.

METHODS

We retrospectively reviewed adult T1-T2 PTC patients with no LLNM retrieved from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2015. We also collected data from patients treated at the First Hospital of China Medical University between February and April 2021 for external validation. Logistic regression model was used to construct a risk prediction model nomogram. The receiver-operating characteristic (ROC) curve, calibration plot, and decision curve analyses (DCA) were used for assessing the nomogram.

RESULTS

5,094 patients from the SEER database and 300 patients from our department were finally included in this study. Variables such as age, gender, race, tumor size, multifocality, and minimal extrathyroidal extension (mETE) were found to be associated with CLNM and were subsequently incorporated into our nomogram. The C-index of our constructed model was 0.704, while the internal and external validation C-indexes were 0.693 and 0.745, respectively. The nomogram was then evaluated using calibration and decision curve analyses.

CONCLUSION

A visualized nomogram was successfully developed to predict CLNM in T1-T2 PTC patients without LLNM and assist clinicians in making personalized clinical decisions.

Microwave Ablation versus Surgical Resection for Solitary T1N0M0 Papillary Thyroid Carcinoma

Background Microwave ablation (MWA) has attracted interest as a minimally invasive treatment for papillary thyroid carcinoma (PTC). However, comparisons between MWA and surgical resection (SR) in the management of T1N0M0 PTC are rare. Purpose To compare the technical effectiveness, disease progression, and complications of MWA and SR for solitary T1N0M0 PTC. Materials and Methods This retrospective study was conducted in a single center. A total of 1029 patients with T1N0M0 PTC treated with either MWA or SR from January 2015 to May 2021 were studied and divided into two groups according to treatment modality. Propensity score matching and inverse probability of treatment weighting were used to control for confounding factors. Disease progression was analyzed in T1N0M0 PTCs as well as T1a and T1b subgroups by using Kaplan-Meier curves and Cox proportional hazards regression models. Results A total of 404 patients (mean age, 43 years ± 12 [SD]; 289 women; 337 with T1a PTC) underwent MWA, and 625 (mean age, 46 years ± 12; 495 women; 521 with T1a PTC) underwent SR. During the follow-up (median, 25 months; IQR, 7-61 months), there was no evidence of differences regarding disease progression in T1N0M0 (4.0% vs 4.0%; P = .97), T1a (3.4% vs 3.8%; P = .89), or T1b PTCs (6.8% vs 5.0%; P = .72). Compared with SR, MWA resulted in less blood loss (2 mL vs 10 mL) and a shorter procedure time (23 minutes vs 72 minutes) (both P < .001). The rate of major complications was 5.4% (19 of 350 patients) in the MWA group and 6.3% (22 of 350 patients) in the SR group (P = .75). Permanent hoarseness only occurred in the SR group (1.7%; P = .03). Conclusion For T1a and T1b solitary T1N0M0 papillary thyroid carcinomas, there was no evidence of differences regarding disease progression and major complications between microwave ablation and surgical resection. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by vanSonnenberg and Simeone in this issue.

Evaluating the safety and efficacy of microwave ablation in treatment of cervical metastatic lymph nodes of papillary thyroid carcinoma compared to repeat surgery

OBJECTIVE

To evaluate the safety and efficacy of microwave ablation (MWA) versus repeat surgery for treating metastatic lymph nodes (MLNs) in papillary thyroid carcinoma (PTC).

METHODS

Between July 2017 and October 2020, 67 patients were enrolled in this retrospective study. 19 and 48 patients underwent MWA and repeat surgery, respectively. The primary and secondary endpoints were recurrence-free survival and complication rates, respectively. The largest diameter, volume and volume reduction ratio (VRR) were analyzed before and after MWA. The effects of different ablation powers on the largest diameter, volume and VRR were investigated. Pre and posttreatment variables (e.g., baseline characteristics, serum thyroglobulin [Tg] levels, hospitalization time, treatment costs, recurrence-free survival and complication rates) were compared between groups.

RESULTS

The largest diameter and volume postablation at each follow-up were smaller than the preablation levels (p < 0.05), except at the 1-month follow-up (p > 0.05). The largest diameter, volume, and VRR among the different ablation powers were not significantly different (p > 0.05). The mean serum Tg levels and biochemical remission rates were not significantly different between the groups (p > 0.05). Compared to reoperation, MWA had a shorter hospitalization time and lower treatment cost (p < 0.001). Total and minor complications were higher in the reoperation group (p < 0.05), but major complications were comparable (p > 0.05). The recurrence-free survival rate between groups was not significantly different (p = 0.401). The 1- and 3-year recurrence-free survival rates were comparable between the groups.

CONCLUSIONS

MWA may be a safe and effective alternative to repeat surgery for treating MLNs of PTC in select patients.

The efficacy and safety of microwave ablation versus conventional open surgery for the treatment of papillary thyroid microcarcinoma: a systematic review and meta-analysis

Background

Microwave ablation (MWA) technology has been applied to the treatment of papillary thyroid microcarcinoma (PTMC); however, its use as an alternative to conventional open surgery (OS) remains controversial, because it belongs to non-tumor radical treatment. Our article sought to compare the efficacy and safety of MWA and OS in the treatment of PTMC.

Methods

We searched seven databases for studies evaluating the treatment of patients with PTMC using MWA as intervention group and OS as control group, the main outcome contained intra-operative, post-operative and follow-up outcomes. Review Manager 5.4 was used to estimate the effects of the results of the included articles and Cochrane Risk of Bias 2.0 was used to assess the risk of bias. The data were pooled to calculate the mean differences (MD) with 95% confidence intervals (CIs) for the continuous data and the odds ratio (OR) with 95% CIs for the dichotomous data.

Results

A total of 13 studies, comprising 1,088 and 1,081 patients in the MWA and OS groups, respectively, were identified that compared the results of MWA to OS in the treatment of PTMC. All of the articles were at low risk of bias. There were no differences in terms of the recurrence rate (OR =0.80, 95% CI: 0.37 to 1.77; P=0.59) or lymph node metastasis (OR =0.71, 95% CI: 0.26 to 1.95; P=0.51) between the 2 groups. However, compared to the OS group, the MWA group had a shorter operation time (MD =-44.85, 95% CI: 5.73 to 20.68; P<0.00001), less intra-operative blood loss (MD =-23.37, 95% CI: -29.57 to -17.17; P<0.00001), a smaller surgical incision (MD =-47.04, 95% CI: -81.93 to -12.14; P=0.008), a shorter postoperative hospital stay (MD =-4.19, 95% CI: -5.46 to -2.92; P<0.00001), lower hospitalization expenses (MD =-85.65, 95% CI: -133.86 to -37.45; P<0.00001), and fewer complications (OR =0.23, 95% CI: 0.16 to 0.33; P<0.00001).

Conclusions

This meta-analysis suggests that MWA is better than OS at treating PTMC in terms of both intra-operative and post-operative outcomes. Due to the quality and number of the included studies, the long-term effects and suitability of MWA in the treatment of PTMC need to be further studied.

Safety and efficacy of ultrasound-guided thermal ablation in treating T1aN0M0 and T1bN0M0 papillary thyroid carcinoma: A meta-analysis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common thyroid tumor, and early diagnosis and treatment can effectively improve prognosis. Many controversies surround the treatment method of T1N0M0 PTC. Recently, thermal ablation (TA) has shown some benefits in the treatment of PTC patients, but the safety and efficacy of its treatment remain controversial. This article performs a meta-analysis of TA in patients with T1aN0M0 and T1bN0M0 PTC.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched for retrospective or prospective studies of TA for treating patients with T1N0M0 PTC from the database establishment to May 1, 2022. Data on volume reduction rate (VRR), disease progress, and complication rate were collected. In addition, a meta-analysis was performed using the Stata 12.0 and Review Manager 5.3.

RESULTS

A total of 9 eligible studies were included. Our study demonstrated the effectiveness of VRR and disease progress. The VRR was reduced after 3 months (-75.90%; 95% CI [-118.46-33.34%]), 6 months (34.33%; 95% CI [15.01-53.65%]), 12 months (78.69%; 95% CI [71.69-85.68%]), and 24 months (89.97%; 95% CI [84.00-95.94%]). The disease progress was 1.9% (95% CI [1.1-3.0]). Safety is justified by the complication rate, which was 6.5% (95% CI [3.5-10.2]). Pain and hoarseness were the most common complications, and no life-threatening complications were reported. Egger's test demonstrated that publication bias was acceptable.

CONCLUSIONS

TA is an effective and safe method for managing T1aN0M0 and T1bN0M0 papillary thyroid nodules.

Over than three-year follow-up results of thermal ablation for papillary thyroid carcinoma: A systematic review and meta-analysis

BACKGROUND

This study is a meta-analysis based on evidence-based medicine to explore the long-term (≥3 years) efficacy of thermal ablation in the treatment of papillary thyroid carcinoma (PTC).

METHODS

We searched the PubMed, Embase, and Cochrane Library databases for studies published during the time between the establishment of the databases through June 2022. We included 13 non-randomized-controlled trials (non-RCTs) that reported the application of ultrasound-guided thermal ablation in PTC. We excluded studies that were repeated publications, research without full text, contained incomplete information, lacked data extraction, involved animal experiments, reviews, and systematic reviews. STATA 15.1 software was used to analyze the data.

RESULTS

Tumor volume after thermal ablation at 3-year follow-up was significantly lower than pre-ablation (standardized mean difference [SMD] = -1.06, 95% CI: -1.32~-0.80). The pooled results indicated that the maximum diameter after thermal ablation at 3-year follow-up was significantly lower than pre-ablation (SMD = -1.93, 95% CI: -12.13~-1.73). The pooled results indicated that volume reduction rate (VRR) after thermal ablation at 3-year follow-up was 98.91% (95% CI: 97.98-99.83%), and complete disappearance rate (CDR) after thermal ablation at 3-year follow-up was 83% (95% CI: 67-94%). In addition, the incidence of newly discovered mPTC and lymph node metastases after thermal ablation was 0.3% (95% CI: 0.0-1.0%) and 0.0% (95% CI: 0.0-0.0%), respectively.

CONCLUSION

Overall, the long-term (≥3 years) efficacy of ultrasound-guided thermal ablation in the treatment of PTC was significant, with favorable disease progression. Ultrasound-guided thermal ablation can be considered an alternative approach for patients with PTC who refuse surgery or are unable to undergo surgery.