Efficacy of radiofrequency ablation for recurrent thyroid cancer invading the airways

Chinese management guidelines for radioactive iodine-refractory differentiated thyroid cancer (2025 edition)

PURPOSE

Radioactive iodine-refractory differentiated thyroid cancer (RAIR-DTC) has become a challenge in clinical practice, particularly in China with a high incidence and undesirable survival outcome. Since the publication of first China consensus on the diagnosis and treatment of RAIR-DTC in 2019, significant and rapid advances have occurred in the field both in China and internationally. This guideline aims to inform Chinese clinicians, researchers, patients, and health policy makers on the latest evidence and recommendations, to further standardize the clinical diagnosis and treatment of RAIR-DTC.

METHODS

The structured clinical questions addressed in this guideline were derived from clinical diagnostic and treatment processes, with references to study, prior guidelines, expert consensus, and systematic reviews, etc. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used for quantitative and qualitative evaluation of the evidence. The editorial process was completely independent of the guideline development group.

RESULTS

The guideline addressed 26 clinical questions and formed 35 recommendations. In this guideline, the definition criteria for RAIR-DTC was optimized, prediction and identification was based on evidence including molecular testing, dynamic biochemical changes, and multimodal imaging. Comprehensive pre-treatment clinical evaluation was emphasized and tailored for individualized decision-making. The combination of systematic therapy and surgery, and the redifferentiation followed by RAI therapy were also reviewed and updated. Molecular imaging plays a unique role in the pre-assessing and therapeutic response evaluation for RAIR-DTC.

CONCLUSIONS

We have updated and developed evidence-based recommendations with the aim of providing scientific, rigorous, and comprehensive guidance for the clinical diagnosis and treatment of RAIR-DTC patients in China. We hope to share our guideline with colleagues out of China, with the expectation of further comments and suggestions.

Preliminary Report Examining Efficacy and Safety of Radiofrequency Ablation for the Treatment of Skin-Involving Recurrent Thyroid Cancer

Background: This study assessed the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for treatment of skin-involving recurrent thyroid cancer. Methods: In this retrospective case series study, 43 patients (mean age: 67.9 ± 14.4 years; 31 females) with skin-involving recurrent thyroid cancer were treated with RFA for a total of 50 tumors between May 2008 and March 2023. The location of the tumor was classified into epidermis, dermis, or hypodermis on the basis of the involved skin layer. After RFA, the technique efficacy (absence of detectable vasculature and volume reduction at 12 months), clinical success (resolution of symptoms or cosmetic problems), volume reduction ratio (VRR), complete disappearance of tumor, and complications were assessed. Results: Of the 50 recurrent tumors, 9 involved the epidermis, 10 involved the dermis, and 31 involved the hypodermis. A total of 88 RFA sessions (mean, 1.8; range: 1-6) were performed. The technique efficacy at 1 year was 72% (36/50 [confidence interval or CI: 59.6-84.4%]). At the last follow-up (median [interquartile range]: 2.7 [1.1-4.5] years), the clinical success rate was 86% (44/50), the complete disappearance rate 54% (27/50), and the mean VRR 77.3% ± 44.2%. In a subgroup analysis comparing epidermis/dermis vs. hypodermis, there was no statistical difference in technique efficacy (57.9% [11/19] vs. 80.6% [25/31], p = 0.085), clinical success rate (78.9% [15/19] vs. 90.3% [28/31], p = 0.265), complete disappearance rate (42.1% [8/19] vs. 51.6% [16/31], p = 0.541), or mean VRR (65.5% vs. 84.6%, p = 0.141). Skin burns were observed in 4.9% per treatment session (2/41 [CI: 0-11.3%]) of epidermis/dermis-involving tumor procedures and none of the hypodermal tumor procedures. No patients experienced life-threatening or major complications. Conclusions: RFA might serve as a promising approach for managing skin-involving recurrent thyroid cancer, with no major complications reported in this preliminary study. Recurrent tumors involving the epidermis/dermis may pose a higher risk of skin burns than tumors involving the hypodermis. Early intervention with RFA before the tumor extends to the epidermis/dermis may thus be preferable.

Radiofrequency Ablation for Locoregional Structural Incomplete Response in Differentiated Thyroid Cancer: Initial Experience in Greece

Background/Objectives: Structural incomplete response (SIR) (persistence/recurrence) may occur in 2-6% of low-risk differentiated thyroid cancer (DTC)-cases and in 67-75% of high risk. Regarding locoregional disease, surgery is the optimal therapeutic modality if the smallest dimension of the targeted node is ≥8 mm or ≥10 mm (central or lateral compartment). In the presence of smaller nodes, contraindications or the patient's unwillingness for reoperation, active surveillance (AS) or minimally invasive treatments (MITs) may be considered. Methods: We retrospectively studied eight DTC patients with SIR confirmed by ultrasound (U/S)-guided fine-needle aspiration cytology (FNAC) and the measurement of Thyroglobulin (Tg) in the washout fluid. Fourteen malignant lesions were ablated by radiofrequency (RF). We assessed prior to RF ablation (RFA) and consecutively at one month, three months and, then, every three months the volume of each lesion, serum Tg and Anti-Tg antibodies and calculated the volume reduction ratio (VRR). Results: Patients were followed for a mean period of 13.25 months (range: 4-24) after RFA was performed. The targeted lesions reduced significantly from a median volume of 0.24 mL (range: 0.09-0.9) to 0.02 mL (range: 0-0.03) (p < 0.05), with a median VRR of 94.5% (range: 78-100%) and concomitant significant biochemical remission (decrease in serum Tg from a median of 1.05 ng/mL to 0.2 ng/mL, p < 0.05). In one patient with an aggressive radioiodine (RAI)-refractory histological variant, re-recurrence was documented, which was successfully re-ablated by RF. In two patients, Horner syndrome was diagnosed as an RFA complication, which was totally resolved within six months. Conclusions: RFA may be considered as an effective and safe MIT in selective DTC patients with SIR, especially in cases of smaller lesions. Additional prospective studies are needed, including aggressive DTC histological variants towards a tailored therapeutic approach.

Role of radiofrequency ablation in the treatment of symptomatic distant metastasis of thyroid cancer

OBJECTIVE

To evaluate the effectiveness and safety of radiofrequency ablation (RFA) for the treatment of symptomatic distant metastasis of differentiated thyroid carcinoma.

MATERIALS AND METHODS

The medical records of 12 patients who underwent RFA for the palliative treatment of 18 symptomatic distant metastases from thyroid cancer between January 2008 and December 2020 were analyzed. All patients were assessed for their degree of discomfort and underwent periodical evaluations as outpatients, including clinical examination, imaging, and serologic markers.

RESULTS

Among the 18 tumors treated, nine were soft tissue, and nine were bone metastases. The mean size of the treated tumors was 5.3 cm (range, 1.7-10.7 cm). All patients complained of pain, discomfort and/or bulging of the metastatic mass before RFA. After RFA, 11 out of the 18 patients with metastatic tumors (61.1%) reported a subjective improvement in symptoms. Nine out of 18 tumors decreased in size, with a mean size reduction ratio of 43% ± 22%. Although symptom improvement was achieved in 61.1% of the tumors, after a mean follow-up duration of 37.4 months, five patients experienced progression of the tumor, four patients had a stable tumor status, and three patients died from pneumonia. There were no major adverse events related to RFA during the treatment or follow-up period.

CONCLUSION

RFA can be used as palliative therapy to relieve the symptoms caused by metastatic tumors; however, it has a limited role in improving the overall prognosis in patients with distant metastasis from thyroid cancer.

Radiofrequency Ablation for Recurrent Thyroid Cancers: 2025 Korean Society of Thyroid Radiology Guideline

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

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.

Value of radiofrequency ablation for treating locally recurrent thyroid cancer: a systematic review and meta-analysis for 2-year follow-up

PURPOSE

To evaluate the safety and efficacy of radiofrequency ablation (RFA) in treating locoregional recurrent thyroid cancer (LRTC) after a 2-year follow-up time.

METHODS

PubMed, Embase and Cochrane Library were searched from inception until 20 September 2022 to find studies reporting the safety and efficacy of RFA in LRTC patients after a 2-year follow-up. Two radiologists performed the data extraction and methodological quality assessment according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We analyzed 6 studies, 229 LRTC patients with 319 locally recurrent tumors were treated with RFA. The mean follow-up time of each study was ≥24 months. The pooled changes in the largest diameter and volume were 7.22 mm (95% confidence interval (CI), 6.35-8.09 mm) and 164.28 mm3 (95% CI, 87.78-240.77 mm3), respectively; the pooled volume reduction rate was 95.03% (95% CI, 87.56-102.49%). The total complete disappearance rate after treatment was 92% (95% CI, 83-100%). The pooled decrease of serum thyroglobulin levels was 0.02 ng/ml (95% CI, -0.00-0.04 ng/ml). The pooled proportion of recurrence rate was 6% (95% CI, 0-13%). The pooled complication rate was 5% (95% CI, 0-10%). The major complications were voice change and hoarseness, only one patient developed permanent vocal cord paralysis; minor complications were cough and pain.

CONCLUSIONS

Ultrasound-guided RFA is an effective and safe treatment for LRTC based on 2-year follow-up results.

Ten-Year Outcomes of Radiofrequency Ablation for Locally Recurrent Papillary Thyroid Cancer

OBJECTIVE

This study investigates the long-term efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for treating locally recurrent papillary thyroid cancer (PTC).

MATERIALS AND METHODS

We retrospectively analyzed 39 consecutive patients with 61 locally recurrent PTCs (14 males, 25 females; mean ± standard deviation age, 52.8 ± 16.7 years; range 21-92 years) who underwent US-guided RFA with curative intent between September 2008 and April 2012. A subgroup of 24 patients with 37 recurrent PTCs who had a follow-up of at least 10 years were analyzed separately. All patients were followed for changes in lesion size on US and thyroglobulin (Tg) levels at 1, 3, 6, and 12 months after RFA, with follow-up every 6-12 months thereafter. Any complications were documented during the follow-up period. Recurrence-free survival (RFS) rates were assessed using Kaplan-Meier estimates. Long-term outcomes were evaluated in patients with follow-up of at least 10 years.

RESULTS

The follow-up period ranged from 7 to 180 months (median 133 months). The RFS rates for the 39 patients at 3, 5, and 10 years were 86.8%, 75.5%, and 60.6%, respectively. Among the 24 patients with 37 recurrent PTCs followed for more than 10 years, the volume reduction rate was 99.9% (range 96%-100%), and the complete tumor disappearance rate was 91.9%. The mean serum Tg level also decreased significantly, from 2.66 ± 86.5 mIU/L before ablation to 0.43 ± 0.73 mIU/L (P < 0.001) at the final follow-up. In 14 (58.3%) of the 24 patients, Tg levels were undetectable (below 0.08 mIU/L) at the last follow-up. No life-threatening or delayed complications were observed during the 10-year follow-up period.

CONCLUSION

The high RFS throughout the follow-up period, with efficacy and safety lasting beyond 10 years, supports US-guided RFA as a valuable option for local control of recurrent PTCs.

Thermal ablation for the treatment of malignant thyroid nodules: present and future

As the utilization of high-resolution imaging modalities, such as ultrasound, becomes increasingly prevalent, there has been a swift rise in the detection rates of malignant thyroid nodules (MTC). Surgery remains the cornerstone of standard treatment for these nodules. However, the advent and evolution of thermal ablation (TA) techniques, encompassing radiofrequency ablation, laser ablation, and microwave ablation, have emerged as a novel therapeutic avenue for patients with MTC, particularly for those deemed unsuitable for surgery due to high risks or for those who refuse surgery. Presently, TA has been validated as an efficacious and safe intervention for both benign thyroid nodules and a subset of MTC. An expanding body of research has been dedicated to broadening the applicability of TA, initially from recurrent thyroid cancer and lymph nodes to now encompass isolated papillary thyroid microcarcinomas (PTMC) alongside a comprehensive exploration into the expanded parameters such as size, number, and location of PTMC, and its applicability in other types of thyroid cancer. This review provides a detailed synthesis of the clinical evidence about the use of TA in the management of MTC, as endorsed by current guidelines. It further delves into the ongoing research efforts aimed at extending its indications and discusses the prospective implications and challenges of integrating TA into the clinical management paradigms for MTC.

Salvage radiofrequency ablation followed by external beam radiotherapy for inoperable recurrent differentiated thyroid cancer

PURPOSE

The treatment of recurrent thyroid cancer with critical organ invasion is challenging. The combination of radiofrequency ablation (RFA) and external beam radiation therapy (EBRT) has been proposed as an effective option. This study evaluates outcomes for inoperable residual/recurrent differentiated thyroid cancer (rDTC) patients treated with RFA followed by EBRT.

MATERIALS AND METHODS

Patients with rDTC treated with RFA followed by EBRT were retrospectively studied. RFA was performed using a free-hand, 'moving-shot' technique under US or CT guidance. For lesions invading critical structures intolerant to 'en bloc' high-temperature RFA, limited-field EBRT using 6- or 10-MV photons was used for adjuvant treatment at a dose of 66 Gy in 33 daily fractions. Toxicities and outcomes were reviewed.

RESULTS

Between April 2020 and January 2022, 11 patients with 14 rDTC lesions underwent RFA followed by EBRT. Five patients had metastatic lesions at rDTC diagnosis. With a median follow-up period of 33.7 months, all patients maintained locoregional control, while achieving a 2-year survival rate of 90.9%. This combined treatment achieved a volume reduction ratio of 92.1% ± 5.1%. The mean nadir thyroglobulin level in patients without initial distant metastases after treatment was 1.40 ± 0.81 ng/ml. Regarding treatment-related complications, one patient (9%) experienced temporary hoarseness after RFA, grade 2 radiation dermatitis occurred in 3 patients (27.2%), and grade 2 dysphagia was noted in 4 patients (36.4%). No grade 3 or greater toxicities occurred.

CONCLUSIONS

Salvage RFA followed by EBRT is feasible, effective and safe for patients with rDTC.

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.

Radiofrequency Ablation for Benign Nodules and for Cancer, Too?

Radiofrequency ablation (RFA) is a minimally invasive procedure performed under ultrasound guidance that offers the ability to significantly reduce the size of benign thyroid nodules. Although application for benign nodules has only emerged during the past 5 to 10 years in North America, RFA has an impressive track record of nodule reduction, compressive and cosmetic symptom improvement, and excellent safety profile without the morbidity of open surgery. The role of RFA in autonomous functioning nodules, thyroid cancer, and indeterminate nodules is controversial and remains an area of investigation.

Differentiated thyroid carcinoma: An update

Differentiated thyroid carcinoma (DTC) is the most common endocrine cancer. Particularly the incidence of small clinically indolent tumors has been increasing significantly during the last decades because of increased diagnostic scrutiny, while the DTC-related mortality remained unchanged. In light of the increased awareness of the significant risk of detecting clinically indolent tumors and the potential harm and burden associated with overly diagnosis and the treatment, the approach towards management of DTC recently underwent a critical appraisal. The focus lays on reducing the unnecessary burden for patients with very low risk DTC and the correct identification of those who require treatment that is more intensive and/or follow-up. Management of DTC includes a range of different modalities, making multidisciplinary collaboration expedient. In this review, we elaborate on the recent developments in diagnosis, staging and management of DTC with specific focus on the more individualized risk assessment-based approach.

Efficacy, safety, and controversy of ultrasound-guided radiofrequency ablation in the treatment of T1N0M0 papillary thyroid carcinoma

Objective

To evaluate the safety effect, and controversy on the treatment outcomes of radiofrequency ablation (RFA) for T1N0M0 papillary thyroid carcinoma (PTC).

Materials and methods

This study is assessed the medical records of 142 patients with primary T1N0M0 PTC tumors after RFA between 2014 and 2022. 4 patients underwent delayed surgery (DS) after RFA and 411 T1N0M0 patients underwent DS were recorded. Outcomes were compared between RFA and DS groups after propensity score matching (PSM).

Results

The maximal diameter (MD) and volume (V) increased in months 1 (P < 0.01) and reduced after the 6-month follow-up (all P < 0.01). The disappearance and disease progression rates were 53.5% and 2.1%, respectively. The complication and disease progression rates had no significant difference between RFA and DS (P>0.05). In some cases, the tumors were not fully inactivated after RFA, and the central compartment lymph node (CCLN) were metastasis. The CCLN metastasis rate was 13.4%. MD, V and clustered calcifications were independent risk factors for CCLN metastasis by univariate analysis.

Conclusions

RFA is an effective and safe treatment option in selected patients with solitary T1N0M0 PTC. There are the risks of tumor incompletely ablated and CCLN metastasis.

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 of radiofrequency ablation for metastatic papillary thyroid cancer with and without initial biochemical complete status

OBJECTIVE

The application of radiofrequency ablation (RFA) for recurrent thyroid cancer has been demonstrated to effectively manage lesions at critical locations, such as abutting the trachea, with limited complications. Comprehensive investigation of both biochemical (B) and structural (S) change after RFA remains limited. We herein present the first single-center experience of RFA for the treatment of locoregional recurrent thyroid cancer in Taiwan.

DESIGN

23 patients were enrolled, and the treatment responses after RFA were divided into four groups (E, S(+), B(+), and SB(+)), and then compared. The RFA technique, follow-up strategy, changes in pre-and post-operative status, and complications are presented. The volume reduction rate at 1, 3, and 6 months, and the differing responses between lesions abutting/not abutting the trachea are also discussed.

RESULTS

In patients with pre-RFA structural and biochemical incomplete (SB(+)) status, presenting with lesion with an initial maximum diameter of >3.2cm, a higher rate of structural incomplete status at the 6-month follow-up was noted in ROC analysis, with a sensitivity of 57% and specificity of 91%. Favorable structural remission after RFA was noted, and 60.9% of patients achieved biochemical complete status. No significant correlation was noted between the trachea-abutted lesion number and complete remission (p= 0.474). No significant difference in RFA efficacy was noted between the lesions abutting/not abutting the trachea.

CONCLUSIONS

This retrospective study reveals that RFA can achieve both structural and biochemical improvements for locoregionally recurrent thyroid cancer, with a low complication rate. Nearly half of the patients achieved an excellent response after RFA, while a favorable treatment response can be achieved despite the lesion abutting the trachea, with a mean VRR of 84.74%.

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.

Tracheal necrosis following thyroid radiofrequency ablation

INTRODUCTION

Radiofrequency ablation for benign thyroid nodules has a low rate of complications in experienced hands for selected indications, but tracheal necrosis is a major complication.

CASE REPORT

A 60 year-old female patient underwent percutaneous radiofrequency ablation of an unesthetic benign isthmic thyroid nodule. The procedure was performed with a cooled electrode, using the "moving shot" technique on a trans-isthmic approach, under general anesthesia. Postoperative course was complicated by dysphonia and cervical pain implicating a third-degree skin burn of the medial cervical region progressing to severe soft-tissue and cervical tracheal necrosis.

DISCUSSION

Risk factors in the present case included the general anesthesia, isthmic location and thyroid nodule volume. To avoid this kind of complication, the procedure should be performed under local anesthesia, using cooled dextrose solution hydrodissection between trachea, thyroid and skin. Ahead of radiofrequency ablation, patients should be informed of possible major complications, especially if the indication is cosmetic.

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.

Assessment of thyroid-specific quality of life in patients with benign symptomatic thyroid nodules treated with radiofrequency or ethanol ablation: a prospective multicenter study

Purpose

Radiofrequency ablation (RFA) and ethanol ablation (EA) are effective and safe for benign symptomatic thyroid nodules (BSTNs). However, relatively little is known about the effects of these procedures on patients’ quality of life (QoL). This prospective, multicenter study evaluated the effects of RFA and EA on changes in thyroid-specific QoL in patients with BSTNs and assessed the volume reduction and safety of these procedures.

Methods

Eighty-six consecutive patients with 86 BSTNs were prospectively included from two medical centers. RFA was performed for 55 BSTNs with solidity ≥50% and EA was performed for 31 BSTNs with solidity <50%. QoL was evaluated using an 11-scale, multiple-choice thyroid-specific QoL questionnaire. Nodule characteristics and QoL were evaluated at diagnosis and 1, 6, and 12 months after treatment. Overall QoL was rated from 0 (good) to 4 (poor).

Results

The mean longest size and volume of the index nodule were 4.2±1.5 cm and 21.6±22.1 mL, respectively. Patients received 1.1 treatments on average (range, 1 to 2). Significant post-treatment volume reductions were noted; however, the EA group showed a higher volume reduction than the RFA group at 1 (78.7%-16.1% vs. 49.1%-15.8%), 6 (86.3%-21.7% vs. 73.0%-14.5%), and 12 (90.9%-14.9% vs. 80.3%-12.4%) months. The score for each scale of the QoL questionnaire improved significantly during follow-up (all P<0.001). Overall QoL improved significantly, from 1.7±0.9 at diagnosis to 0.6±0.7 at the 12-month follow-up (P<0.001). There were no major complications.

Conclusion

Both RFA and EA are safe and effective in reducing nodule volume and improving thyroid-specific QoL in patients with BSTNs.

Current Status and Challenges of US-Guided Radiofrequency Ablation of Thyroid Nodules in the Long Term: A Systematic Review

BACKGROUND

US-guided minimally-invasive techniques, such as radiofrequency ablation (RFA) have emerged as an alternative treatment for benign and malignant thyroid nodules. This systematic review aims to provide an overview on the long-term outcomes of US-guided RFA in patients with benign and malignant thyroid nodules.

METHODS

We systematically searched PubMed/MEDLINE, EMBASE, and Scopus to identify articles reporting the outcomes of thyroid RFA after a follow-up of at least 3 years.

RESULTS

A total of 20 studies met the inclusion criteria and were included in the review. In patients with benign thyroid nodules, RFA significantly reduced nodule volume and this was generally maintained for the following 5 years. However, a small but not negligible proportion of nodules regrew and some of them required further treatments over time. In patients with malignant nodules, RFA has been used not only to treat differentiated thyroid cancer (DTC) neck recurrences, but also to treat papillary thyroid microcarcinoma (PTMC). In most patients with PTMC, RFA led to complete disappearance of the tumor. When it was compared to surgery, RFA was not inferior in terms of oncologic efficacy but it had a lower complication rate. However, RFA did not allow for final pathology, disease staging and accurate risk stratification.

CONCLUSIONS

US-guided RFA significantly reduces benign thyroid nodules and destroys most PTMC, and this is generally maintained for at least 5 years after the initial treatment. Further studies addressing the risk of regrowths in patients with benign thyroid nodules, as well as the risk of recurrence in patients with PTMC are needed.

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.

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.