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.

Prognostic factors and treatment responses among patients with gross residual disease in differentiated thyroid cancer.

BACKGROUND: Various postoperative staging systems were developed to assess the outcome of differentiated thyroid cancer from initial risk after surgery to dynamic changing prognosis during follow-up. The objective of our retrospective cohort study was to identify risk factors contributing to macroscopic positive surgical margin (R2 resection) and parameters in discriminating the treatment responses and prognosis among R2 patients. METHODS: In total, 242 differentiated thyroid cancer patients with extrathyroidal extension who underwent a thyroidectomy at Kaohsiung Chang Gung Memorial Hospital between January 2013 and July 2018, were included. The patients were grouped according to the presence or absence of gross residual disease (R2). The R2 patients were further classified into two categories according to their treatment response into excellent and nonexcellent groups. The parameters and treatment outcomes were compared between these groups. RESULTS: The mean follow-up time was 45.3 months. Two hundred seven (85.5%) patients had either surgery-free or microscopic margins (R0/R1), while 35 (14.5%) had R2 resection. In the R2 group (n = 35), 15 (42.9%) patients achieved an excellent response, while 20 (57.1%) achieved a nonexcellent response. Statistically significant differences were observed in the extent of neck dissection, TSH-Tg level, post-RAI Tg level, nodal status, and recurrence between the two groups. The Kaplan-Meier curves for 5-year local and distant recurrence-free survival of R0/R1 versus R2 patients were 90.0% versus 66.3%, and 98.4% versus 90.7%, respectively ( p < 0.001). Among the R2 patients, the excellent responders had a higher local recurrence-free survival than nonexcellent responders (93.3% vs. 45.1%, p = 0.008). CONCLUSION: There are significant disparities in recurrence-free survival among R2 patients with different treatment responses. The nodal status of papillary thyroid cancer and thyroglobulin level after thyroidectomy and RAI were factors contributing to difference in their treatment responses.

Preoperative work-up and results of parathyroidectomy plus auto-transplantation for the elderly with secondary hyperparathyroidism.

BACKGROUND: Total parathyroidectomy for secondary hyperparathyroidism has low morbidity and mortality rates and requires a special workup in the preoperative period. METHODS: Neck echography and technetium-99m-sestamibi scintigraphy were performed preoperatively. Cardiac echography, a thallium-201 myocardial perfusion scan, and cardiac catheterization were performed if necessary. During surgery, we removed all the parathyroid glands and the upper thymus and autotransplanted 100 mg of the smallest gland into the subcutaneous tissue of the forearm. RESULTS: The success rate in three months after total parathyroidectomy was 91.7% without mortality. In the elderly (age ≤65 years, n = 35), bone pain, skin itching, general weakness, and insomnia improved three months after surgery, and grip strength increased significantly. One year after parathyroidectomy, the serum levels of Ca, P, alkaline phosphatase, and intact parathyroid hormone were all within the normal ranges. Except for the bone mineral density (BMD) of the radial distal one-third, the BMD of the lumbar spine (L2 to L4), femoral neck, femoral global, and radial global increased significantly. Furthermore, the bone density T-scores of the lumbar spine (L2 to L4), femoral neck, femoral global, radial distal one-third, and radial global improved significantly. CONCLUSIONS: After a meticulous preoperative workup, parathyroidectomy plus autotransplantation can be performed safely for the treatment of symptomatic secondary hyperparathyroidism in the elderly to improve their quality of life and decrease their incidence of bone fractures.

Radiofrequency ablation for thyroid Bethesda III nodules: preliminary results.

Purpose: The purpose of this study was to evaluate the feasibility of radiofrequency ablation (RFA) for thyroid nodules with cytological atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS, Bethesda III). Materials and methods: A total of 28 adults presenting with 30 initial Bethesda III nodules underwent thyroid RFA at a single medical center. Thyroid nodules with Bethesda IV or V according to the second aspiration were excluded. All RFA procedures were performed using the free-hand, 'moving-shot' technique under local anesthesia. Clinical features and demographics, RFA details, nodule volume reduction rate (VRR), and complications were analyzed. Results: The mean age of patients was 47.6 years, 82.1% of whom were females. Mean nodule volumes at pre-RFA, and at 6 months and 12 months post-RFA were 7.92, 2.42, and 1.25 mL, respectively, with a VRR of 77.9% at 6 months, and 87.4% at 12 months. Post-RFA complications were noted in two patients, one with transient vocal cord palsy and another with isthmus minor rupture. Conclusion: RFA may be another safe alternative except for active surveillance or surgical excision for AUS/FLUS nodules with low-suspicion Thyroid Imaging Reporting and Data System features for patients who are unsuitable or strongly refuse surgery. Long-term results remain uncertain, thus further follow-up study is necessary.

Factors Influencing a Favorable Outcome for RFA of Huge Benign Thyroid Nodules: Preliminary Results and Short-Term Evaluation.

Objective: This study aimed to investigate potentially favorable factors influencing the therapeutic success of radiofrequency ablation (RFA) of huge benign thyroid nodules (BTNs) (volume >100 ml) and to evaluate the feasibility of RFA as an alternative treatment modality for patients unable or unwilling to undergo surgery. Methods: This retrospective study evaluated a total of 868 patients, of which 22 patients had huge BTNs who underwent ultrasound-guided moving shot RFA treatment between May 2017 and January 2022. The huge BTNs were categorized into two groups according to a post-RFA treatment volume reduction ratio (VRR) of >80% and <80% at 6 months. Factors influencing these huge BTNs were reviewed, analyzed, and correlated with treatment effectiveness between the two groups. Results: The factors influencing an effective VRR included huge BTNs located on the left side (OR 7.875, p = 0.03), predominant solid/spongiform nodules (OR 7.875, p = 0.03), and higher initial ablation rate (IAR) (p = 0.028). Multivariable logistic regression revealed predominant solid/spongiform nodule and the higher IAR were associated with the advanced VRR. Conclusion: RFA was effective at decreasing the volume of huge BTNs with an acceptable complication rate. The BTN characteristics correlated with a better VRR at the 6-month short-term follow-up were predominant solid/spongiform BTNs and those with the first time ablation treatment initial ablation rate. Nevertheless, regarding the higher regrowth rate of these groups of patients who may need to be treated more times, RFA can only be a feasible alternative treatment modality for patients unable or unwilling to undergo operation.

Radiofrequency ablation for thyroid Bethesda III nodules: preliminary results.

Purpose: The purpose of this study was to evaluate the feasibility of radiofrequency ablation (RFA) for thyroid nodules with cytological atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS, Bethesda III). Materials and methods: A total of 28 adults presenting with 30 initial Bethesda III nodules underwent thyroid RFA at a single medical center. Thyroid nodules with Bethesda IV or V according to the second aspiration were excluded. All RFA procedures were performed using the free-hand, 'moving-shot' technique under local anesthesia. Clinical features and demographics, RFA details, nodule volume reduction rate (VRR), and complications were analyzed. Results: The mean age of patients was 47.6 years, 82.1% of whom were females. Mean nodule volumes at pre-RFA, and at 6 months and 12 months post-RFA were 7.92, 2.42, and 1.25 mL, respectively, with a VRR of 77.9% at 6 months, and 87.4% at 12 months. Post-RFA complications were noted in two patients, one with transient vocal cord palsy and another with isthmus minor rupture. Conclusion: RFA may be another safe alternative except for active surveillance or surgical excision for AUS/FLUS nodules with low-suspicion Thyroid Imaging Reporting and Data System features for patients who are unsuitable or strongly refuse surgery. Long-term results remain uncertain, thus further follow-up study is necessary.

Clinical Impact of Androgen Receptor-Suppressing miR-146b Expression in Papillary Thyroid Cancer Aggressiveness.

CONTEXT: Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Dysregulated expression of miR-146b and androgen receptor (AR) has been shown to play critical roles in tumorigenesis in PTC. However, the mechanistic and clinical association between AR and miR-146b is not fully understood. OBJECTIVE: The purpose was to investigate miR-146b as the potential AR target miRNA and its involvement in advanced tumor characteristics of PTC. METHODS: Expression of AR and miR-146b were assessed in frozen and formalin-fixed paraffin-embedded tissue samples from PTC and adjacent normal thyroid specimens by quantitative real-time polymerase chain reaction, and their correlation was examined. Human thyroid cancer cell lines BCPAP and TPC-1 were used to evaluate the effect of AR on miR-146b signaling. Chromatin immunoprecipitation (ChIP) assays were performed to determine whether AR binds to the miR-146b promoter region. RESULTS: Pearson correlation analysis confirmed significant inverse correlation between miR-146b and AR expression. Overexpressing AR BCPAP and TPC-1 cells showed relatively lower miR-146b expression. ChIP assay revealed that AR might bind to the androgen receptor element located on the promoter region of miRNA-146b gene, and overexpression of AR suppresses miR-146b-mediated tumor aggressiveness. The low AR/high miR-146b PTC patient group was associated with advanced tumor characteristics, including higher tumor stage, lymph node metastasis, and worse treatment response. CONCLUSION: To sum up, miR-146b is a molecular target of AR transcriptional repression; therefore, AR suppresses miR-146b expression to reduce PTC tumor aggressiveness.

2022 Taiwan clinical multicenter expert consensus and recommendations for thyroid radiofrequency ablation.

Radiofrequency ablation (RFA) is a minimally invasive management strategy that has been widely applied for benign and recurrent malignant thyroid lesions as an alternative to surgery in Taiwan. Members of academic societies for specialists in interventional radiology, endocrinology, and endocrine surgery collaborated to develop the first consensus regarding thyroid RFA in Taiwan. The modified Delphi method was used to reach a consensus. Based on a comprehensive review of recent and valuable literature and expert opinions, the recommendations included indications, pre-procedural evaluations, procedural techniques, post-procedural monitoring, efficacy, and safety, providing a comprehensive review of the application of RFA. The consensus effectively consolidates advice regarding thyroid RFA in clinical practice for local experts.

Localization Strategy Prior to Radiofrequency Ablation for Primary and Secondary Hyperparathyroidism.

OBJECTIVE: Preoperative localization in patients with primary or secondary hyperparathyroidism before radiofrequency ablation (RFA) is crucial. There is currently a lack of consensus regarding imaging protocol. Evaluating the diagnostic performance of ultrasound, four-dimensional computed tomography (4D-CT), and technetium 99m-sestamibi single-photon-emission-computed tomography/computed tomography (SPECT/CT) is necessary for RFA of hyperparathyroidism. METHODS: This retrospective study recruited patients with primary or secondary hyperparathyroidism who underwent ultrasound, 4D-CT, and SPECT/CT before RFA at a single institution. The sensitivity, accuracy, and receiver operating characteristic curve analysis were used to evaluate the diagnostic performance of the imaging modalities. RESULTS: A total of 33 patients underwent RFA for hyperparathyroidism (8 patients with primary hyperparathyroidism, 25 patients with secondary hyperparathyroidism). Ultrasound had the highest sensitivity (0.953) and accuracy (0.943), while 4D-CT had higher sensitivity and accuracy than SPECT/CT (sensitivity/accuracy, 4D-CT vs. SPECT/CT: 0.929/0.920 vs. 0.741/0.716). Combined ultrasound with 4D-CT and the three combined modalities achieved equivalent, and the highest, diagnostic performance (sensitivity 1.000, accuracy 0.989). The lesion length and volume were important predictors of the diagnostic performance of 4D-CT and SPECT/CT (area under curve of length in 4D-CT/volume in 4D-CT/length in SPECT/volume in SPECT: 0.895/0.834/0.767/0.761). CONCLUSION: Combined ultrasound with 4D-CT provides optimal preoperative localization prior to RFA in patients with primary or secondary hyperparathyroidism. The length and volume of parathyroid lesions are determinative of the diagnostic performance of 4D-CT and SPECT/CT.

Combination of treatments with transoral endoscopic thyroidectomy vestibular approach (TOETVA) for Graves' disease.

Although the success rates of non-surgical treatments for Graves' disease such as antithyroid medication and radioiodine ablation were good, there were still failure of treatments or intolerance for some patients. Traditional thyroid surgery could treat these patients but result in unaesthetic neck scars. Herein, we report the preliminary results of our combination of treatments with the transoral endoscopic thyroidectomy vestibular approach for Graves' disease. A retrospective review of patients who underwent the transoral endoscopic thyroidectomy vestibular approach for the treatment of different sizes of goiters between January 2019 and December 2020 was performed. The demographic and clinical data of patients were collected. All patients were followed up for > 12 months. Each patient's goiter size was determined using four grades-from 0 to 3. In total, 14 female patients receiving the combination treatment with > 1 year of follow-up and a median (range) age of 35 (20-48) years at surgery were included. There were two, three, four, and five patients with grade 0, 1, 2, and 3 goiters, respectively. The median (range) intraoperative blood loss was higher in grade 3 patients (100 [20-850] mL) than in grade 2 patients (20 [10-200] mL) and grade 1 and 0 patients (both < 10 mL) (p = 0.033). All patients had normal-looking necks with a euthyroid or hypothyroid status within 1 year. There were no complications, including re-operation for bleeding, hypoparathyroidism, vocal cord palsy, or infections. The designed combination treatment with the transoral endoscopic thyroidectomy vestibular approach for Graves' disease provides optimal cosmetic results with a high success rate.

Recombinant human thyrotropin versus thyroid hormone withdrawal preparation for radioiodine ablation in differentiated thyroid cancer: Experience in a South Taiwanese medical center.

This retrospective study was designed to compare the treatment response of patients with differentiated thyroid cancer (DTC) prepared for radioiodine ablation (RIA) with thyroid hormone withdrawal (THW) or recombinant human thyrotropin (rhTSH) stimulation. Patients with DTC were followed-up retrospectively between 2013 and 2018 in Kaohsiung Chang Gung Memorial Hospital, Taiwan. We compared the excellent response ratios between THW (49.9%) and rhTSH (50.1%) stimulation. Patients were then divided into subgroups, on the basis of age, sex, extrathyroidal extension, lymph node metastasis, and tumor-node-metastasis stage, for analysis. In all, 647 patients were followed-up after RIA. The ratios of THW or rhTSH use in the different subgroups were not statistically significant. In all the patients, the excellent response rate with THW and rhTSH was 80% and 76.5%, respectively, which was not statistically significant. The subgroup analysis, including age, sex, extrathyroidal extension, lymph node metastasis, and tumor-node-metastasis stage (low and high risk), showed similar results. Furthermore, the logistic regression analysis revealed no statistically significant differences among the subgroups. The multivariate analysis showed extrathyroidal extension, lymph node metastasis, and high I131 dose were the prognostic factors affecting the excellent response rate. In conclusion, the THW and rhTSH preparations for RIA were similar in terms of the excellent response rates and subgroup clinical outcomes.

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%.

Efficacy and safety of radiofrequency ablation for primary and secondary hyperparathyroidism with or without previous parathyroidectomy: a retrospective study.

INTRODUCTION: This study aimed to investigate and compare the therapeutic efficacy and safety of ultrasound-guided radiofrequency ablation (RFA), between primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT) patients, with or without previous parathyroidectomy (PTX). SUBJECTS AND METHODS: A total of 21 patients (7 PHPT, 14 SHPT) underwent RFA for hyperparathyroidism (HPT) at Kaohsiung Chang Gung Memorial Hospital, Taiwan. Five of the 14 SHPT patients had previously received PTX. The laboratory data, volume change of each parathyroid nodule, symptomatic scores, and complications were analyzed and compared between all groups at 1 and 7 days, and at 1, 3, 6, and 12 months after RFA. RESULTS: After RFA, the volume reduction ratio (VRR) for all patients at the last follow-up was 93.76%, and clinical symptoms significantly improved. At 12 months, all PHPT patients achieved successful treatment of intact PTH (iPTH). In SHPT patients, the mean iPTH value significantly decreased 1-day post-RFA, subsequently exhibiting a transient rebound which proceeded to decrease, with 57.1% reaching successful treatment standards. SHPT patients with PTX showed a lower complication score, shorter ablation time, higher iPTH baseline and outcomes, and lower VRR, compared to patients without PTX. The serum calcium level significantly decreased to normal range in 85.7% of all patients at 12 months. Severe hypocalcemia occurred in 23.8% at 1 week, and all were corrected with calcium supplements. CONCLUSIONS: RFA demonstrates a therapeutic efficacy similar to PTX. It can thus be considered an effective alternative treatment for PHPT, SHPT, or post-PTX patients who are unsuitable for another PTX.

Impact of Thyroid Incidentaloma on Liver Transplant: A Study of 1010 Recipients at a Single Center.

BACKGROUND Thyroid incidentalomas are typically nonpalpable thyroid nodules discovered during radiographic evaluation for a non-thyroid issue. Thyroid incidentalomas visualized by computed tomography (CT) and ¹8F-flurodeoxyglucose (FDG) positron emission tomography (PET) before living donor liver transplantation (LDLT) are rare. The aim of the study was to analyze the clinical impact of thyroid incidentalomas discovered prior to transplantation. MATERIAL AND METHODS This retrospective study recruited 1010 patients undergoing LDLT between 2010 and 2019. CT was performed on each patient, whereas PET was performed on randomized patients (n=498). RESULTS The prevalence and malignant risk of thyroid incidentaloma on CT was 2.3% (23/1010) and 13.0% (3/23), respectively. The prevalence of thyroid incidentaloma on PET was 3.0% (15/498). Approximately half of the FDG uptake on PET was diffuse uptake (n=7), whereas the other half was focal uptake (n=8). The malignant risk of PET incidentaloma with focal FDG uptake was 37.5% (3/8). Four asymptomatic thyroid cancers were identified incidentally. After total thyroidectomy followed by LDLT, these patients maintained cancer-free status. CONCLUSIONS Thyroid incidentalomas occurred at a rate of 2-3% in LDLT candidates. The malignant risk was 13.0% on CT incidentaloma, and 37.5% on PET incidentaloma with focal FDG uptake. Curative treatment of incidental thyroid cancer followed by LDLT without delay can achieve a favorable prognosis.

Decreased Expression of Estrogen Receptors Is Associated with Tumorigenesis in Papillary Thyroid Carcinoma.

Papillary thyroid carcinomas (PTC), which is derived from thyroid follicular cells, is the most commonly differentiated thyroid cancer with sex disparity. However, the role of estrogen receptors (ERs) in the pathogenesis of PTC remains unclear. The present study aimed to determine the association of ER mRNA expression levels with clinicopathologic features in PTC. To that aim, the mRNA levels of ESR1 (ERα66), ESR1 (ERα36), ESR2, and G-protein-coupled estrogen receptor 1 (GPER1) in snap-frozen tissue samples from PTCs and adjacent normal thyroid tissues were determined using quantitative reverse transcription polymerase chain reaction (RT-qPCR), and the correlation between ER mRNA expression levels and clinicopathologic features was analyzed. The expression of ERα66, ERα36, ERß, and GPER1 was lower in PTC specimens than in adjacent normal thyroid tissues. Moreover, low GPER1 expression was associated with extrathyroidal extension. There was no obvious difference in expression of ERs between PTC specimens from male and female patients. In conclusion, our findings highlight the importance of ERs in PTC tumorigenesis.

Changes in voice quality, swallowing, and pulmonary function after parathyroidectomy for secondary hyperparathyroidism.

OBJECTIVE: To find changes in voice quality, airway invasion during swallowing, pharyngeal residue after swallowing, acoustic and aerodynamic measurements and pulmonary function tests after total parathyroidectomy plus auto-transplantation for secondary hyperparathyroidism. METHODS: We recruited 38 patients who underwent successful surgery for secondary hyperparathyroidism in this study. Voice quality was evaluated using voice handicap index (VHI-10), eating assessment tool (EAT-10), voice impairment, and the grade, roughness, breathiness, asthenia, strain (GRBAS) scale. Acoustic and aerodynamic measurements included fundamental frequency (F0), maximal phonation time, high pitch, jitter, s/z, shimmer and noise-to-harmonic ratio. Vocal cord mobility, vocal cord closure, premature spillage, the penetration-aspiration scale and the Yale pharyngeal residue severity rating scale (PRSRS) after swallowing were examined using fiber-optic endoscopy. Pulmonary function tests included forced vital capacity, forced expiratory volume in 1 s, bronchodilator test, total lung capacity, diffusion capacity of the lung for carbon monoxide, alveolar volume, and distance and O2 desaturation of the 6 min walking test (6MWT). RESULTS: Four months after successful parathyroidectomy, VHI-10 improved significantly (p < 0.01); incomplete vocal cord closure decreased significantly (p < 0.01); the Yale PRSRS for vallecula and pyriform sinus improved significantly (p = 0.02 and p = 0.02); F0 and high pitch increased significantly (p < 0.01 and p = 0.01); O2 desaturation (<4%) of 6MWT improved significantly (p = 0.04). CONCLUSIONS: Parathyroidectomy for secondary hyperparathyroidism can improve the voice quality, vocal cord closure, the Yale PRSRS for vallecular and pyriform sinus and O2 desaturation of 6MWT, and increase F0 and high pitch.

One year follow-up of US-Guided radiofrequency ablation for low-risk papillary thyroid microcarcinoma: The first experience in Taiwan.

BACKGROUND: The incidence of papillary thyroid microcarcinoma (PTMC) has increased rapidly in recent decades, with a favorable overall prognosis. We aimed to evaluate the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for treating low-risk PTMC in Taiwan. METHODS: This prospective study included patients with PTMC who were ineligible or refused surgery and underwent US-guided RFA between October 2018 and June 2020. US and computed tomography (CT) were performed before RFA to assess tumor lesions and exclude cervical lymph node metastasis. Sequential US follow-up following RFA was performed after 1, 3, 6, and 12 months, and yearly thereafter. Volume reduction ratio (VRR) and complete disappearance rate of tumor at one year were evaluated. RESULTS: 13 PTMCs in 12 patients were enrolled with a mean follow-up of 16.2 ± 8.1 months (range, 1-24 months). The median largest tumor diameter and tumor volume before RFA were 0.76 cm and 0.15 ml (range, 0.02-0.37 ml). The median (interquartile range, IQR) volume and VRR at 12 months post-RFA were 0 (0, 0.03) ml (p = 0.033) and 100% (84.26%, 100%) (p = 0.008). Eight tumors (61.54%) were completely disappeared at 12 months post-RFA and no tumor recurrence, lymph nodes, or distant metastasis were noted. All tumors were successfully treated without complications. CONCLUSION: Minimally invasive US-guided RFA is an effective and safe alternative for low-risk PTMC, resulting a satisfied VRR.

Efficacy and safety of single-session radiofrequency ablation for intrathoracic goiter: preliminary results and short-term evaluation.

BACKGROUND: An intrathoracic goiter (ITG) is defined as a thyroid extension below the sternal notch. Compared to cervical goiters, surgery for ITG is more challenging, with a higher risk of an extracervical approach. Ultrasound (US)-guided radiofrequency ablation (RFA) is a minimally invasive treatment modality. The purpose of this study was to prospectively evaluate the safety and efficacy of RFA in patients with ITG. METHODS: From a total of 324 patients who underwent thyroid RFA at a single medical center, 15 patients (mean age 52.2 years; 73.3% female) with 16 ITGs were included and classified into three grades and three types using the cross-section imaging CT system. Clinical features and demographics, degree of extension, RFA details, goiter volume, and complications were analyzed. RESULTS: Mean pre- and post-RFA goiter volumes as measured by US were 106.62 ± 61.82 and 25.09 ± 14.22 mL respectively, with a volume reduction rate (VRR) of 75.5% (p < 0.001) at 6 months. The VRR as measured by CT/MRI was 57.0 ± 10.0% (p < 0.001) at 6 months. The intrathoracic length reduction rate at 6 months was 44.9 ± 39.2% (p = 0.001). In addition, 4 (25%) ITGs had total regression of the intrathoracic extension, with a downgrade from grade 1 to cervical goiter. Mean pre- and post-RFA symptom and cosmetic scores were 1.53 and 0.15 (p = 0.001), and 2.67 and 2.00 (p = 0.001), respectively. One patient had transient vocal cord palsy and another had perithyroidal and mediastinal hemorrhage. CONCLUSION: US-guided RFA is an effective treatment for ITG in terms of both cervical and intrathoracic reductions with an acceptable complication rate.

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.

Scarless Completion Thyroidectomy After Initial Transoral Approach for Differentiated Thyroid Cancer: How and When to Start?

BACKGROUND: With growing literature, the feasibility of transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been confirmed as a valid method for managing differentiated thyroid cancer. Completion thyroidectomy (CT) is recommended in patients who have been diagnosed with differentiated thyroid cancer after unilateral lobectomy by TOETVA. In this retrospective study, the authors addressed the critical questions of how and when to do the second operation of CT to avoid a neck scar. MATERIALS AND METHODS: The authors retrospectively reviewed our patients who had received TOETVA in our hospital from August 2016 to December 2019. Those who received CT after initial TOETVA as cTOETVA were further separated according to the approaching methods. Demographic data, operative variables, and postoperative variables were collected and analyzed. RESULTS: A total of 97 patients were enrolled using TOETVA. Malignancies were present in 42 patients (43.3%) using TOETVA. There were 3 approaching methods of cTOETVA and separated into reopen transcervical approach (re-TCA), retransoral TOETVA (re-TOETVA), and transaxillary approach (TAA) groups. There were no significant complications among patients for cTOETVA. Of the 8 patients for the cTOETVA, 3 received re-TCA, 3 re-TOETVA, and 2 TAA. CONCLUSIONS: The outcomes are encouraging and demonstrate the feasibility of scarless completion thyroidectomy after initial TOETVA. The re-TOETVA procedure should be completed within 14 days after the initial TOETVA procedure, TAA beyond 14 days, and re-TCA may be completed at any time. The cTOETVA techniques using re-TOETVA or TAA have better cosmetic results than re-TCA in oncological equivalency.