Ultrasonography-guided radiofrequency ablation vs. surgery for the treatment of solitary T1bN0M0 papillary thyroid carcinoma: A comparative study

Three-year follow-up results of radiofrequency ablation for low-risk papillary thyroid microcarcinomas: Systematic review and meta-analysis

OBJECTIVES

Confidence in long-term treatment results of radiofrequency ablation (RFA) for papillary thyroid microcarcinoma (PTMC) is required in comparison with surgery and active surveillance (AS). The objective of this meta-analysis is to report more than three years of follow-up results of radiofrequency ablation for PTMCs.

METHODS

Ovid PUBMED, COCHRANE, and EMBASE databases were searched through Nov 19, 2023, for studies reporting outcomes in patients with PTMC treated with radiofrequency ablation and followed up for more than 3 years. The standard mean difference of the tumor volume before and after therapy, tumor recurrence, lymph node (LN) metastasis, distant metastasis, complications, and the pooled volume reduction rates (VRRs) at 1, 3, 6, 12, 24, 36, and 48 months after radiofrequency ablation were assessed. Data were extracted and methodological quality was assessed independently by two radiologists according to the PRISMA guidelines.

RESULTS

Eight studies, involving 2131 patients, met the inclusion criteria through database searches. The overall VRR was 99.81 % (95 % CI: 99.68, 99.95) in the last follow-up. During a mean pooled follow-up of 46.59 months, 69 patients experienced local PTMC recurrence, with 8 cases within the ablation area. Additionally, 44 patients were diagnosed with newly discovered PTMC, and 17 patients exhibited lymph node metastases. Among the patients with PTMC recurrence, 3 were under active surveillance while 59 underwent additional RFA. The pooled mean complication rate was 2.80 %, with no instances of life-threatening or delayed complications.

CONCLUSIONS

Radiofrequency ablation proves to be an effective local tumor control method for low-risk PTMC patients, resulting in clinically significant and enduring volume reduction. The rate of regrowth and retreatment requirement post-RFA was notably lower, positioning RFA as a compelling alternative to existing treatment options.

A study on the safety and efficacy of endoscopic thyroidectomy via axillary approach for the treatment of thyroid cancer

This study aims to evaluate the safety and efficacy of endoscopic thyroid cancer treatment using an axillary approach. Participants were allocated into 2 groups: one undergoing transaxillary endoscopic surgery and the other, traditional open surgery. We compared intraoperative and postoperative conditions, focusing on parameters such as intraoperative blood loss, duration of surgery, length of postoperative hospitalization, volume of postoperative drainage, number of lymph nodes cleared in the central region, neck pain scores, neck injury indices, cosmetic satisfaction, postoperative complications, and total hospitalization duration. Patients in the endoscopic treatment (ET) group experienced longer surgical times, less intraoperative bleeding, and increased postoperative drainage. These indicators showed significant differences between the groups (P < .05). For the group undergoing endoscopic surgery via the axillary approach, there was a lower neck pain score on the third postoperative day and higher cosmetic satisfaction at 3 months. However, there were no significant differences between the groups in terms of the number of lymph nodes cleared in the central area, and the incidence of complications such as difficulty breathing, difficulty swallowing, hoarseness, and subcutaneous hematoma (P > .05). The axillary approach endoscopic surgery group also showed significantly prolonged surgery times and postoperative hospital stays, with a significant increase in postoperative drainage fluid (P < .05). Concurrently, this technique involved smaller surgical incisions and effectively concealed scars in the armpit, leading to better outcomes in terms of intraoperative bleeding, neck pain scores, and postoperative cosmetic satisfaction. Non-inflatable ET via the axillary approach for treating thyroid cancer demonstrates promising efficacy and safety. It offers additional benefits of minimal pain and enhanced cosmetic outcomes, making it a viable option for clinical adoption and application.

Ultrasound-guided radiofrequency ablation for the treatment of papillary thyroid carcinoma: a review of the current state and future perspectives

Papillary thyroid carcinoma (PTC) is a highly prevalent cancer that typically exhibits indolent behavior and is associated with a favorable prognosis. The treatment of choice is surgical intervention; however, this approach carries the risk of complications, including scarring and loss of thyroid function. Although active surveillance can mitigate the risk of PTC overtreatment, the possibility of tumor growth and metastasis can elicit anxiety among patients. Ultrasoundguided thermal ablation has emerged as a safe and effective alternative for individuals who are ineligible for or decline surgery. This article provides a review of the clinical research on radiofrequency ablation as a treatment for PTC, offering a thorough examination of its efficacy, safety, and future perspectives.

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.

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.

Clinical outcomes of ultrasound-guided radiofrequency ablation for solitary T1N0M0 papillary thyroid carcinoma: A retrospective study with more than 5 years of follow-up

BACKGROUND

Ultrasound-guided radiofrequency ablation (RFA) has been used in patients with papillary thyroid carcinoma (PTC) who refuse surgery or active surveillance. However, the long-term outcomes are still limited. This study aimed to evaluate the clinical outcomes of RFA for solitary T1N0M0 PTC in a large cohort over a more than 5-year follow-up period.

METHODS

This retrospective study included 358 patients with solitary T1N0M0 PTC who were treated with RFA and followed for at least 5 years. The bipolar RFA procedure was performed using hydrodissection technique, transisthmic approach, and moving-shot technique. The primary outcomes were disease progression, including lymph node metastasis (LNM), recurrent tumor, persistent tumor, and distant metastasis. The secondary outcomes were volume reduction rate, complete disappearance rate, complications, and delayed surgery.

RESULTS

During a mean follow-up period of 75.5 ± 9.7 months, the overall disease progression was 5.0%. The incidence of LNM, recurrent tumor, and persistent tumor was 1.4%, 3.1%, and 0.6%, respectively. There were no significant differences in the disease progression (5.0% vs. 5.5%, p = 1.000), LNM (1.3% vs. 1.8%, p = .568), recurrent tumor (3.3% vs. 1.8%, p = .872), persistent tumors (0.3% vs. 1.8%, p = .284), and 5-year recurrence-free survival rates (95.4% vs. 96.4%, p = .785) in the T1a and T1b groups. Volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. No complications occurred. No patients underwent delayed surgery because of anxiety.

CONCLUSIONS

RFA is an effective and safe alternative for patients with T1N0M0 PTC and can offer a minimally invasive curative option for patients who refuse surgery or active surveillance.

PLAIN LANGUAGE SUMMARY

During a mean follow-up period of 75.5 ± 9.7 months, the overall papillary thyroid carcinoma disease progression was 5.0%. The volume reduction rate was 100.0 ± 0.3%, with 96.9% of tumors disappearing. The T1a and T1b groups had similar incidence of disease progression and 5-year recurrence-free survival rates. No patients experienced complications or underwent delayed surgery because of anxiety.

Surgical treatment of thyroid cancer: Established and novel approaches

Thyroid surgery is one of the most common head and neck procedures. The thyroid can be accessed through an anterior cervical incision, or by remote access techniques such as the transoral endoscopic thyroidectomy vestibular approach (TOETVA) which is favored for its ease, safety and direct plane to the thyroid gland. Other novel approaches for targeting small-localized well-differentiated thyroid cancer are by thermal ablation, namely ultrasound guided radiofrequency ablation. These innovative techniques for minimizing a cutaneous scar or for targeting small cancers directly without removal of the gland have developed alongside our realization that low risk well-differentiated thyroid cancer tends to be slow growing and indolent. Up to date, the most robust data supports offering these therapies primarily to patients who would be eligible for active surveillance protocols. In this paper, we review the traditional surgical approaches for removing well-differentiated thyroid cancer, as well as innovative remote access techniques (namely TOETVA), and minimally invasive thermal ablation (namely RFA).

A clinical study on microwave ablation of multifocal (≤ 3) T1N0M0 papillary thyroid carcinoma

OBJECTIVE

To evaluate the feasibility, efficiency, and safety of microwave ablation (MWA) for T1N0M0 multifocal (≤ 3) papillary thyroid carcinoma (PTC).

METHODS

This was a retrospective study, and patients who underwent MWA for multifocal (≤ 3) PTC were reviewed between October 2016 and December 2020. After ablation, the changes in tumor size and volume, as well as the rate of technical success, tumor disappearance, disease progression, and complications were assessed.

RESULTS

There were a total of 57 cases enrolled in the present study, which included 18 males and 39 females. The mean age was 44 ± 11 years (22-66 years); the mean follow-up time was 18 ± 11 months (6-48 months). Complete ablation was achieved in all enrolled cases. Therefore, the technical success rate was 100%. Due to expanding ablation, the MD and volume of the ablation zone, as well as the VRR, increased at the 1st and 3rd months after ablation and decreased at 12 and 18 months after ablation (p < 0.05 for all). The total complete tumor disappearance rate was 43.9% (25/57), including 54% (24/44) in the T1a subgroup vs. 7.7% (1/13) in the T1b subgroup (p = 0.003). The total disease progression rate was 7% (4/57), including 9.1% (4/44) in the T1a subgroup vs. 0% (0/13) in the T1b subgroup (p = 0.142). The overall complication rate was 5.3% (3/57), including 6.8% (4/44) in the T1a subgroup vs. 0% (0/13) in the T1b subgroup (p = 0.206).

CONCLUSION

This preliminary study indicates that MWA is a safe and effective treatment for T1N0M0 multifocal (≤ 3) PTC.

KEY POINTS

• MWA is a promising alternative method for T1N0M0 multifocal (≤ 3) PTC.

SFE-AFCE-SFMN 2022 consensus on the management of thyroid nodules: Thermal ablation

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). This section deals with thermal ablation, which may constitute an alternative to thyroid surgery in selected patients.

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.

Efficacy and Safety of Different Thermal Ablation Modalities for Papillary Thyroid Microcarcinoma: A Network Meta-Analysis

Background

Small thyroid-like carcinoma (PTMC) is one of the most common subtypes of thyroid cancer. The main treatment options include surgery and radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA). Thermal ablation has the advantage of being less invasive and has fewer complications than traditional surgical treatment.

Objective

The objective is to explore the efficacy and safety of PTMC by different thermal ablation modalities through a network meta-analysis.

Methods

From the database establishment to October 2021, a computerized search of the Chinese Knowledge Infrastructure (CKNI), VIP Chinese Science and Technology Journal Full-Text Database (VP-CSJFD), WanFang Data journal article resource (WangFang), PubMed, the Cochrane Library, and Embase were performed to include the different methods of thermal ablation for small thyroid carcinoma. A retrospective study of different methods of thermal ablation of small thyroid carcinoma was included.

Results

A total of 12 retrospective studies involving 1,926 patients with PTMC were included, all of which were of high quality. This study mainly involved RFA, MWA, LA, and ethanol combined with radiofrequency ablation (EA + RFA). Network meta-analysis showed no significant difference between interventions (p > 0.05) in terms of recurrence rate.

Conclusions

Surgical resection may be the measure with the lowest recurrence rate after treatment of PTMC, LA may be the measure with the lowest incidence of complications after treatment, and RFA may be the measure with the least length of hospital stay, operation time, and postoperative lymph node metastasis rate. However, due to the limitations of network meta-analysis, this result still needs to be treated with caution, and more high-quality, large-sample clinical studies are recommended for further verification.

Comparison of ultrasound-guided radiofrequency ablation versus thyroid lobectomy for T1bN0M0 papillary thyroid carcinoma

OBJECTIVE

To investigate and compare the clinical outcomes between radiofrequency ablation (RFA) and thyroid lobectomy (TL) for T1bN0M0 papillary thyroid carcinoma (PTC).

METHODS

This retrospective study evaluated 283 patients with solitary T1bN0M0 PTC treated with RFA (RFA group, 91 patients) or TL (TL group, 192 patients) from May 2014 to November 2018. The patients were regularly followed up after treatment. Local tumor progression, lymph node metastasis (LNM), recurrent tumor, persistent tumor, recurrence-free survival (RFS), treatment variables (hospitalization, procedure time, estimated blood loss, and cost), complication, and delayed surgery were compared.

RESULTS

During the follow-up (median [interquartile ranges], 50.4 [18.0] months), no significant differences were found in the local tumor progression (4.4% vs 3.6%, p = 1.000), LNM (1.1% vs 2.1%, p = 0.917), recurrent tumor (2.2% vs 1.6%, p = 1.000), persistent tumor (1.1% vs 0%, p = 0.146), and RFS rate (95.6% vs 96.4%, p = 0.816) in the RFA and TL groups. Distant metastasis was not detected. Patients in the RFA group had a shorter hospitalization (0 vs 7.0 [3.0] days, p < 0.001), shorter procedure time (5.6 [2.9] vs 90.0 [38.5] min, p < 0.001), lower estimated blood loss (0 vs 20 [20] mL, p < 0.001), lower cost ($1972.5 [0.1] vs $2362.4 [1009.3], p < 0.001), and lower complication rate (0 vs 12/192 [6.3%], p = 0.015) than those in the TL group. No patients in the RFA group underwent delayed surgery.

CONCLUSIONS

This study revealed comparable 4-year clinical outcomes between RFA and TL for T1bN0M0 PTC in terms of local tumor progression and RFS. As a minimally invasive modality, RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

KEY POINTS

• No significant difference in local tumor progression and RFS was found between RFA and TL for T1bN0M0 PTC during a median follow-up period of 50.4 months. • Compared with TL, RFA led to a shorter hospitalization, lower estimated blood loss, lower cost, and lower complication rate. • RFA may be a promising feasible alternative to surgery for the treatment of T1bN0M0 PTC in selected patients after strict evaluation.

Research Review of Thermal Ablation in the Treatment of Papillary Thyroid Carcinoma

Background

Minimally invasive treatment of thyroid tumors has become increasingly common, but has mainly focused on benign thyroid tumors, whereas thermal ablation of thyroid cancer remains controversial. Clinical studies analyzing the efficacy of thermal ablation of papillary thyroid carcinoma (PTC) have been conducted in several countries to verify its safety. Here, we screened and reviewed recent studies on the efficacy and safety of thermal ablation of PTC as well as psychological assessment, patient prognosis, recurrence, and factors affecting ablation.

Summary

The most significant controversy surrounding ablative treatment of PTC centers on its effectiveness and safety, and >40 studies have been conducted to address this issue. The studies include papillary thyroid microcarcinoma (PTMC) and non-PTMC, single PTC and multiple PTC, and controlled studies of ablative therapy and surgical treatment. In general, ablation techniques can be carefully performed and promoted under certain conditions and with active follow-up of postoperative patients. Ablation is a promising alternative treatment especially in patients who are inoperable.

Conclusions

Clinical studies on PTC ablation have provided new perspectives on local treatment. However, because PTC grows very slowly, it is an indolent tumor; therefore, studies with larger sample sizes and extended post-procedure follow-ups are necessary to confirm the investigators’ hypotheses.

Role of Fluorodeoxyglucose-PET in Interventional Radiology

Fluorodeoxyglucose (FDG)-PET has expanding applications in the field of interventional radiology. FDG-PET provides both qualitative and quantitative assessments of malignancy, infection, and inflammation. These assessments can assist interventional radiologists in selecting the most appropriate treatment options for their oncology patients. FDG-PET is also useful for evaluating the response to interventional treatments and in predicting the prognosis of oncology patients. Finally, FDG-PET can assist the interventional radiologist in diagnosing and monitoring response to treatment of infection and inflammation. Nevertheless, there is a need for additional prospective studies to further establish the role of FDG-PET in these applications.

American Association of Clinical Endocrinology Disease State Clinical Review: The Clinical Utility of Minimally Invasive Interventional Procedures in the Management of Benign and Malignant Thyroid Lesions

OBJECTIVE

The objective of this disease state clinical review is to provide clinicians with a summary of the nonsurgical, minimally invasive approaches to managing thyroid nodules/malignancy, including their indications, efficacy, side effects, and outcomes.

METHODS

A literature search was conducted using PubMed and appropriate key words. Relevant publications on minimally invasive thyroid techniques were used to create this clinical review.

RESULTS

Minimally invasive thyroid techniques are effective and safe when performed by experienced centers. To date, percutaneous ethanol injection therapy is recommended for recurrent benign thyroid cysts. Both ultrasound-guided laser and radiofrequency ablation can be safely used for symptomatic solid nodules, both toxic and nontoxic. Microwave ablation and high-intensity focused ultrasound are newer approaches that need further clinical evaluation. Despite limited data, encouraging results suggest that minimally invasive techniques can also be used in small-size primary and locally recurrent thyroid cancer.

CONCLUSION

Surgery and radioiodine treatment remain the conventional and established treatments for nodular goiters. However, the new image-guided minimally invasive approaches appear safe and effective alternatives when used appropriately and by trained professionals to treat symptomatic or enlarging thyroid masses.

Efficacy and safety of ultrasound-guided microwave ablation versus surgical resection for Bethesda category IV thyroid nodules: A retrospective comparative study

OBJECTIVE

The objective of this study was to assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) for Bethesda IV thyroid nodules and to compare the outcomes, complications, and costs of MWA and thyroidectomy.

METHODS

A total of 130 patients with Bethesda IV nodules were retrospectively reviewed, involving 46 in the MWA group and 84 in the surgery group. The local institutional review board approved this study. Patients in the MWA group were followed up at 1, 3, 6, and 12 months after the intervention. Postoperative complications, treatment time, and cost in the two groups were compared.

RESULTS

Among 84 patients with 85 Bethesda IV nodules in the surgery group, postoperative pathology was benign lesions, borderline tumors, papillary thyroid carcinoma, follicular variant papillary thyroid carcinoma, follicular thyroid carcinoma, and medullary carcinoma in 44, 4, 27, 6, 3, and 1 cases, respectively. Malignant thyroid nodules were more prone to solid echostructure (86.11% vs. 72.72%), hypoechogenicity (55.56% vs. 13.63%), and irregular margin (47.22% vs. 13.63%) than benign lesions. The nodule volume reduction rate of patients at 12 months after MWA was 85.01% ± 10.86%. Recurrence and lymphatic and distant metastases were not reported during the follow-up period. The incidence of complications, treatment time, hospitalization time, incision length, and cost were significantly lower in the MWA group than in the surgery group (all p < 0.001).

CONCLUSIONS

MWA significantly reduces the volume of Bethesda IV nodules with high safety and is recommended for those with surgical contraindications or those who refuse surgical resection. Patients with suspicious ultrasound features for malignancy should be actively treated with surgery.

Radiofrequency ablation of recurrent thyroid cancers: anatomy-based management

Although differentiated thyroid cancer has an excellent prognosis and low mortality, its recurrence rate has been reported to be very high. While surgery is recommended as the standard treatment for recurrent thyroid cancer, reoperation may increase the incidence of complications due to fibrosis and anatomical distortion. In patients with high surgical risk or those who refuse repeated surgery, ultrasonography-guided ablation techniques including radiofrequency ablation, ethanol ablation, and laser ablation are suggested as alternative treatments. In this manuscript, we introduce an anatomy-based management concept for radiofrequency ablation for recurrent thyroid cancer, and present a review of the relevant literature, including indications, basic techniques, clinical outcomes, and complications.

Nomogram prediction for the involution of the ablation zone after radiofrequency ablation treatment in patients with low-risk papillary thyroid carcinoma

OBJECTIVES

To construct a prognostic nomogram to predict the involution of the ablation zone for patients with low-risk papillary thyroid carcinoma (PTC) who underwent radiofrequency ablation (RFA) treatment.

METHODS

Data from 204 patients with low-risk PTC without extrathyroidal extension or cervical lymph node or distant metastasis who underwent RFA treatment were collected from January 2018 to January 2019. Clinicopathological and imaging characteristics were analyzed. The prognostic factors associated with the involution of the ablation zone within 12 months after RFA were identified by logistic analysis, and the nomogram was established. Calibration curve and decision curve analysis were used to evaluate the nomogram performance.

RESULTS

Of the 204 patients included in this study, the ablation zone in 78 (38%) patients did not completely disappear in the 12 months after RFA. Four variables, including sex (odds ratio [OR], 3.303; 95% confidence interval [CI], 1.418-8.418; p = 0.008), age (OR, 1.045; 95% CI, 1.012-1.081; p = 0.009), calcification size (OR, 1.666; 95% CI, 1.041-2.701; p = 0.035), and RFA energy (OR, 2.902; 95% CI, 1.333-6.683; p = 0.009), were found to be closely associated with ablation zone non-disappearance at 12 months after RFA by multivariate analysis. A nomogram model was constructed, and its accuracy was well validated (C-index = 0.787).

CONCLUSIONS

This study constructed and validated a risk model that could accurately predict the involution of the ablation zone after RFA for patients with PTC. This could provide clinicians with useful resource to guide patient counseling regarding tumor prognosis after RFA.

Radiofrequency ablation for treatment of thyroid follicular neoplasm with low SUV in PET/CT study

OBJECTIVES

To evaluate the feasibility of radiofrequency ablation (RFA) on follicular neoplasm with low standard uptake value (SUV) in a Positron emission tomography (PET/CT) study.

METHODS

From January 2018 to July 2019, 86 consecutive patients were diagnosed with follicular neoplasm. Of the patients, 28 with PET/CT scans were enrolled in this study. All patients received ultrasound, fine/core needle aspiration, and PET/CT scan prior to treatment. In accordance with previous studies, we recommended 6 patients who had follicular neoplasm with SUVmax ≥5 undergo surgical resection due to an elevated suspicion of malignancy. For 22 patients SUVmax <5, RFA was performed using the moving shot technique. Ultrasound was performed 6 to 12 months after each procedure.

RESULTS

Statistically significant volume reductions during follow-up between values prior to RFA and 12 months post RFA were demonstrated (12.6 ± 20.9 vs. 2.4 ± 3.0 cm³, p < 0.001). Volume reduction ratios at 6-12 months (mean: 10.1 months) after RFA were 73.3% ± 17.7%. One patient presented with vocal cord palsy and recovered within 3 months after RFA. No postprocedural hypothyroidism occurred in the RFA patients.

CONCLUSIONS

By using PET/CT, we can select patients with low SUV follicular neoplasm. RFA offers a safe and feasible alternative treatment option for patients unsuitable or unwilling to undergo surgery.KEY POINTSBy using positron emission tomography-computed tomography, we can distinguish low SUV follicular neoplasm for radiofrequency ablation.For low SUV follicular neoplasm, RF ablation offers a safe and effective alternative treatment option for patients unsuitable or unwilling to undergo surgery.

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

The growing detection of papillary thyroid microcarcinomas (PTMCs) is paralleled by an increase in surgical procedures. Due to the frequent indolent nature, cost, and risk of surgery, active surveillance (AS) and ultrasound-guided minimally invasive treatments (MITs) are in suitable cases of incidental PTMC proposed as alternatives to thyroidectomy. Surgery and radioiodine are the established treatments for relapsing cervical differentiated thyroid carcinoma (DTC) metastases. But radioiodine refractoriness, risk of surgical complications, adverse influence on quality of life, or declining repeat surgery have led to AS and MIT being considered as alternatives for slow-growing DTC nodal metastases. Also, for distant radioiodine-refractory metastases not amenable to surgery, MIT is proposed as part of a multimodality therapeutic approach. The European Thyroid Association and the Cardiovascular and Interventional Radiological Society of Europe commissioned these guidelines for the appropriate use of MIT. Based on a systematic PubMed search, an evidence-based approach was applied, and both knowledge and practical experience of the panelists were incorporated to develop the manuscript and the specific recommendations. We recommend that when weighing between surgery, radioiodine, AS, or MIT for DTC, a multidisciplinary team including members with expertise in interventional radiology assess the demographic, clinical, histological, and imaging characteristics for appropriate selection of patients eligible for MIT. Consider TA in low-risk PTMC patients who are at surgical risk, have short life expectancy, relevant comorbidities, or are unwilling to undergo surgery or AS. As laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective thermal ablation (TA) techniques, the choice should be based on the specific competences and resources of the centers. Use of ethanol ablation and high-intensity focused ultrasound is not recommended for PTMC treatment. Consider MIT as an alternative to surgical neck dissection in patients with radioiodine refractory cervical recurrences who are at surgical risk or decline further surgery. Factors that favor MIT are previous neck dissection, presence of surgical complications, small size metastases, and <4 involved latero-cervical lymph nodes. Consider TA among treatment options in patients with unresectable oligometastatic or oligoprogressive distant metastases to achieve local tumor control or pain palliation. Consider TA, in combination with bone consolidation and external beam radiation therapy, as a treatment option for painful bone metastases not amenable to other established treatments.

Efficacy and safety of radiofrequency ablation in the treatment of low-risk papillary thyroid carcinoma: a review

Ultrasound-guided radiofrequency ablation (RFA) has recently been used for the treatment of thyroid carcinomas. In this study, we aimed to evaluate the efficacy and safety of RFA for treating low-risk papillary thyroid carcinomas (PTCs). We searched the MEDLINE and the SCOPUS databases up to December 29, 2020, for studies assessing the efficacy and safety of RFA in the management of low-risk PTCs. Data on volume reduction ratio (VRR), complete disappearance, carcinoma recurrence, and complication frequency were collected. Thirteen studies with a total of 1389 patients and 1422 tumors were included in the synthesis of this study. Mean VRR varied between 47.8 and 100%, with most studies reporting a ratio of 98.5-100%. The ratio of complete disappearance ranged between 33.7 and 100%, although studies with a prolonged follow-up period reported a frequency of 56-100%. The tumor progression/recurrence frequency was 0-4.5%. Complications occurred in 45 patients (3.2%). Mild-moderate pain and cervical discomfort were the most common complications and no life-threatening complications were reported. Based on these data, we suggest that ultrasound-guided RFA can serve as an efficacious and safe alternative for the treatment of low-risk PTC in patients who are unable or unwilling to receive surgical therapy.

Comparison of ultrasound guided percutaneous radiofrequency ablation and open thyroidectomy in the treatment of low-risk papillary thyroid microcarcinoma: A propensity score matching study

PURPOSE

The aim of this study was to evaluate the efficacy, safety and costs of ultrasound guided percutaneous radiofrequency ablation (RFA) versus open thyroidectomy for treating low-risk papillary thyroid microcarcinoma (PTMC) by using propensity score matching (PSM).

PATIENTS AND METHODS

157 patients who underwent RFA and 206 patients who underwent surgery for low-risk PTMC were included in the study. The patients were followed up at 1, 3, 6, 12 months after treatment, and every half year thereafter. A 1:1 PSM method was applied to balance the pretreatment data of the two groups. In the matched group (133 patients for each), the operative time, length of hospital stay, hospitalization expenses, cosmetic results, complications were assessed and compared between two groups.

RESULTS

At last follow-up, 39 tumors (29.3%) in the RFA group completely disappeared. Between the well-matched groups, no local recurrence, lymph node metastasis or distant metastases were detected in either group during the follow-up period. After matching, the operation time and hospitalization time in RFA group were shorter than those in surgery group (both P <  0.05). The average hospitalization expense of the patients in RFA group was cheaper than that in surgery group (P <  0.05). Moreover, the cosmetic score was found to be higher in RFA group than that observed in surgery group (P <  0.05).

CONCLUSIONS

RFA may be an effective and safe method for treating low-risk PTMC with a superior advantage of being low-cost and having a shorter operation time and hospital stay versus surgery.

Ultrasound-Guided Radiofrequency Ablation Versus Surgical Resection for the Treatment of T1bN0M0 Papillary Thyroid Carcinoma in Different Age Groups

PURPOSE

We aimed to compare the efficacy and safety of radiofrequency ablation (RFA) to that of surgical resection (SR) in patients with T1bN0M0 papillary thyroid carcinoma (PTC) in different age groups.

METHODS

Totally, 204 patients with an isolated, solitary, intrathyroidal T1bN0M0 PTC, who underwent either RFA (n=94) or SR (n=110) between April 2014 and December 2019, were retrospectively enrolled and were divided into two subgroups according to age (<45 years, ≧45 years). Patients with pathologically aggressive or advanced lesions were excluded from the study. Tumor progression and procedural complications were the primary and secondary endpoints, respectively. Tumor recurrence in situ, newly discovered tumors, lymph node involvement, or distant metastases indicated tumor progression. Complications included pain, fever, voice change, choking, numbness in the limbs, and cardiac events. Incidence rates of all endpoint events were compared between different age subgroups.

RESULTS

There were no significant differences in age, sex, and tumor size between the treatment groups. While the RFA group incurred less cost and experienced significantly shorter operative duration than the SR group, no significant differences were observed in incidences of both tumor progression and complications. Further, subgroup analysis of patients <45 years versus those ≧45 years showed no significant differences in the incidence of tumor progression and complications within or between different treatment groups. Older patients in the SR group incurred higher hospital costs than younger counterparts, but this difference was not observed in the RFA group.

CONCLUSIONS

Our results indicated that RFA had a similar prognosis as that of SR but was associated with lower overall cost in both young (<45 years) and middle-aged patients (≧45 years) with T1bN0M0 PTC. Therefore, RFA may be an effective and safe alternative to surgery for the treatment of patients with T1bN0M0 PTC.

Update of Radiofrequency Ablation for Treating Benign and Malignant Thyroid Nodules. The Future Is Now

Thermal and chemical ablation are minimally invasive procedures that avoid removal of the thyroid gland and target symptomatic nodules directly. Internationally, Radiofrequency ablation (RFA) is among one of the most widely used thermal ablative techniques, and is gaining traction in North America. Surgery remains the standard of care for most thyroid cancer, and in the right clinical setting, Active Surveillance (AS) can be a reasonable option for low risk disease. Minimally invasive techniques have emerged as an alternative option for patients deemed high risk for surgery, or for those patients who wish to receive a more active treatment approach compared to AS. Herein, we review the literature on the safety and efficacy of RFA for treating benign non-functioning thyroid nodules, autonomously functioning thyroid nodules, primary small low risk thyroid cancer (namely papillary thyroid cancer) as well as recurrent thyroid cancer.