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.

DGA3-Net: A parameter-efficient deep learning model for ASPECTS assessment for acute ischemic stroke using non-contrast computed tomography.

Detecting the early signs of stroke using non-contrast computerized tomography (NCCT) is essential for the diagnosis of acute ischemic stroke (AIS). However, the hypoattenuation in NCCT is difficult to precisely identify, and accurate assessments of the Alberta Stroke Program Early CT Score (ASPECTS) are usually time-consuming and require experienced neuroradiologists. To this end, this study proposes DGA3-Net, a convolutional neural network (CNN)-based model for ASPECTS assessment via detecting early ischemic changes in ASPECTS regions. DGA3-Net is based on a novel parameter-efficient dihedral group CNN encoder to exploit the rotation and reflection symmetry of convolution kernels. The bounding volume of each ASPECTS region is extracted from the encoded feature, and an attention-guided slice aggregation module is used to aggregate features from all slices. An asymmetry-aware classifier is then used to predict stroke presence via comparison between ASPECTS regions from the left and right hemispheres. Pre-treatment NCCTs of suspected AIS patients were collected retrospectively, which consists of a primary dataset (n = 170) and an external validation dataset (n = 90), with expert consensus ASPECTS readings as ground truth. DGA3-Net outperformed two expert neuroradiologists in regional stroke identification (F1 = 0.69) and ASPECTS evaluation (Cohen's weighted Kappa = 0.70). Our ablation study also validated the efficacy of the proposed model design. In addition, class-relevant areas highlighted by visualization techniques corresponded highly with various well-established qualitative imaging signs, further validating the learned representation. This study demonstrates the potential of deep learning techniques for timely and accurate AIS diagnosis from NCCT, which could substantially improve the quality of treatment for AIS patients.

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.

Improving detection of impacted animal bones on lateral neck radiograph using a deep learning artificial intelligence algorithm.

OBJECTIVE: We aimed to develop a deep learning artificial intelligence (AI) algorithm to detect impacted animal bones on lateral neck radiographs and to assess its effectiveness for improving the interpretation of lateral neck radiographs. METHODS: Lateral neck radiographs were retrospectively collected for patients with animal bone impaction between January 2010 and March 2020. Radiographs were then separated into training, validation, and testing sets. A total of 1733 lateral neck radiographs were used to develop the deep learning algorithm. The testing set was assessed for the stand-alone deep learning AI algorithm and for human readers (radiologists, radiology residents, emergency physicians, ENT physicians) with and without the aid of the AI algorithm. Another radiograph cohort, collected from April 1, 2020, to June 30, 2020, was analyzed to simulate clinical application by comparing the deep learning AI algorithm with radiologists' reports. RESULTS: In the testing set, the sensitivity, specificity, and accuracy of the AI model were 96%, 90%, and 93% respectively. Among the human readers, all physicians of different subspecialties achieved a higher accuracy with AI-assisted reading than without. In the simulation set, among the 20 cases positive for animal bones, the AI model accurately identified 3 more cases than the radiologists' reports. CONCLUSION: Our deep learning AI model demonstrated a higher sensitivity for detection of animal bone impaction on lateral neck radiographs without an increased false positive rate. The application of this model in a clinical setting may effectively reduce time to diagnosis, accelerate workflow, and decrease the use of CT.

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.

Deep Learning-Based Automatic Detection of ASPECTS in Acute Ischemic Stroke: Improving Stroke Assessment on CT Scans.

(1) Background: The Alberta Stroke Program Early CT Score (ASPECTS) is a standardized scoring tool used to evaluate the severity of acute ischemic stroke (AIS) on non-contrast CT (NCCT). Our aim in this study was to automate ASPECTS. (2) Methods: We utilized a total of 258 patient images with suspected AIS symptoms. Expert ASPECTS readings on NCCT were used as ground truths. A deep learning-based automatic detection (DLAD) algorithm was developed for automated ASPECTS scoring based on 168 training patient images using a convolutional neural network (CNN) architecture. An additional 90 testing patient images were used to evaluate the performance of the DLAD algorithm, which was then compared with ASPECTS readings on NCCT as performed by physicians. (3) Results: The sensitivity, specificity, and accuracy of DLAD for the prediction of ASPECTS were 65%, 82%, and 80%, respectively. These results demonstrate that the DLAD algorithm was not inferior to radiologist-read ASPECTS on NCCT. With the assistance of DLAD, the individual sensitivity of the ER physician, neurologist, and radiologist improved. (4) Conclusion: The proposed DLAD algorithm exhibits a reasonable ability for ASPECTS scoring on NCCT images in patients presenting with AIS symptoms. The DLAD algorithm could be a valuable tool to improve and accelerate the decision-making process of front-line physicians.

Residual, regrowth, and new growth of radiofrequency ablation for benign thyroid nodules of different volumes: two-year follow-up results.

INTRODUCTION: Radiofrequency ablation (RFA) is recognized as an effective technique for the treatment of benign thyroid nodules (BTNs), although the long-term results are limited. This study aimed to evaluate the residual vital volume increase, regrowth, and new growth over a 2-year period after RFA among different nodule volume groups. SUBJECTS AND METHODS: This retrospective study evaluated 135 patients with 153 BTNs who underwent ultrasound guided RFA. The BTNs were categorized into small (<10 mL), medium (10-30 mL), and large (>30 mL) according to the initial volume of BTNs prior to ablation. The volume changes of each nodule were analyzed at 1, 3, 6, 12 and 24 months after RFA. New growth was defined as the growth in volume not found in the early follow-up on ultrasonography. RESULTS: The initial ablation ratio of all BTNs was 99.67%. The mean volume reduction ratio (VRR) of BTNs was 85.53% after 2-year follow-up. The small nodule group showed a lower VRR compared to the other two groups at the 1-month follow-up, and there was no difference of VRR at the subsequent follow-ups. The incidence of residual vital volume increase was 4.58%. The overall incidence of regrowth was 3.92% and the mean timing of regrowth was 16.71 months. New growth occurred in 18.95% of patients. No further treatment was required in the majority of cases. CONCLUSION: RFA achieved a clinically relevant volume reduction in different sizes of single BTNs which persisted for at least 2 years, thereby preventing the need for retreatment.

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.

Toward automated segmentation for acute ischemic stroke using non-contrast computed tomography.

PURPOSE: Non-contrast computed tomography (NCCT) is a first-line imaging technique for determining treatment options for acute ischemic stroke (AIS). However, its poor contrast and signal-to-noise ratio limit the diagnosis accuracy for radiologists, and automated AIS lesion segmentation using NCCT also remains a challenge. In this paper, we propose R2U-RNet, a novel model for AIS lesion segmentation using NCCT. METHODS: We used an in-house retrospective NCCT dataset with 261 AIS patients with manual lesion segmentation using follow-up diffusion-weighted images. R2U-RNet is based on an R2U-Net backbone with a novel residual refinement unit. Each input image contains two image channels from separate preprocessing procedures. The proposed model incorporates multiscale focal loss to mitigate the class imbalance problem and to leverage the importance of different levels of details. A proposed noisy-label training scheme is utilized to account for uncertainties in the manual annotations. RESULTS: The proposed model outperformed several iconic segmentation models in AIS lesion segmentation using NCCT, and our ablation study demonstrated the efficacy of the proposed model. Statistical analysis of segmentation performance revealed significant effects of regional stroke occurrence and side of the stroke, suggesting the importance of region-specific information for automated segmentation, and the potential influence of the hemispheric difference in clinical data. CONCLUSION: This study demonstrated the potentials of R2U-RNet model for automated NCCT AIS lesion segmentation. The proposed model can serve as a tool for accelerating AIS diagnoses and improving the treatment quality of AIS patients.

Applicability of Oculomotor Tests for Predicting Central Vestibular Disorder Using Principal Component Analysis.

The videonystagmography oculomotor test battery is considered useful method for diagnosing vertigo. However, its role in diagnosing central vestibular disorder has not been clarified due to variations in interpretation. Patients (n = 103) with vertigo or dizziness symptoms undergoing the oculomotor tests and brain MRI within 1 month were analyzed. Two otology specialists retrospectively interpreted the oculomotor tests, and three neurology and neuroradiology specialists determined whether central lesions were present on brain MRI. Multivariable logistic regression analysis was performed to determine the factors contributing to discordant interpretation between oculomotor tests and brain MRI. Oculomotor tests predicting central lesions were assessed using principal component analysis. The intra- and inter-rater reliability in oculomotor test interpretation was moderate to good. Age > 60 years and multiple comorbidities were significant predictors of a discordant interpretation between MRI and oculomotor tests. Positive neurological symptoms and a higher oculomotor index (according to saccade (vertical axis), smooth pursuit (horizontal axis), and gaze-evoked nystagmus (horizontal/vertical axes) tests) significantly predicted central vestibular disorder in vertigo patients. Caution is required when interpreting the results of the oculomotor test battery for diagnosis of central lesions in older patients, as well as in those with multiple comorbidities.

Multicenter Study of Benign Thyroid Nodules with Radiofrequency Ablation: Results of 762 Cases over 4 Years in Taiwan.

BACKGROUND: To evaluate the effectiveness and safety of radiofrequency ablation (RFA) treatment for benign thyroid nodules (BTNs) in five medical centers in Taiwan. METHODS: From April 2016 to July 2020, 762 patients underwent ultrasound guided RFA treatment of 826 benign thyroid nodules at five medical centers in Taiwan. The RFA procedure was performed by radiologists, otolaryngologists, or surgeons. Patients were grouped into three subgroups according to the initial volume of BTNs. The volume reduction ratio (VRR) of each nodule, and complications were analyzed at 1, 3, and 6 months after RFA treatment and the three groups compared. RESULTS: The large nodular group showed greater VRR compared to the other two groups at first 1-month follow-up. At 6-months follow-up, there was no significant difference of VRR among the three groups. Goiters with difference in size can attain a successful VRR (>50%) although different specialists demonstrated variable VRR after 6-months follow-up. A total of 40 (4.8%) complications were reported. All patients recovered spontaneously without surgery intervention. CONCLUSIONS: The reliability and safety of RFA for benign thyroid nodules had been established. RFA has gradually become an alternative to surgery in the treatment of benign thyroid nodules in Taiwan.

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.

Radiofrequency Ablation a Safe and Effective Treatment for Pediatric Benign Nodular Thyroid Goiter.

Purpose: To evaluate the effectiveness of radiofrequency ablation (RFA) for benign thyroid nodules in pediatric patients. Materials and Methods: Twelve pediatric patients (11 female, 1 male; mean age 15.54 ± 2.8 years, range 10-19 years) with benign thyroid nodules (mean longest diameter 4.1 ± 1.4 cm, range 1.5-5.9 cm) treated by RFA from 2017 to 2020 were evaluated. The inclusion criteria for RFA therapy were (i) age < 20 years; (ii) benign cytological confirmation by 2 separate ultrasound guided fine-needle aspiration cytology (FNAC) or core needle biopsies; (iii) pressure symptoms or cosmetic problems caused by thyroid nodules; (iv) absence of any sonographic suspicious feature; and (v) follow-up for >6 months. Under local anesthesia, RFA was performed with the use of an RF generator and an 18-gauge internally cooled electrode. Volume changes in nodules on follow-up ultrasonography (US), changes in symptomatic and cosmetic scores, and complications arising during or after RFA were evaluated. Results: Mean follow-up period was 24.9 ± 13.9 months (range 6-43 months). At the last follow-up visits, volume of the nodule had decreased significantly (15.34 ± 11.52 mL vs. 4.07 ± 4.99 mL; P < 0.05), whereas volume reduction rate was 74.31% ± 19.59%. Both cosmetic and compressive symptoms were also significantly improved (2.91 ± 0.79 vs. 0.92 ± 0.67 and 1.5 ± 1.93 vs. 0.17 ± 0.39; P < 0.05). The mean number of ablation sessions was 1.4 ± 0.6 (range 1-3 sessions), and one of the patients suffered from transient vocal cord palsy which was spontaneously resolved 53 days later. Conclusions: RFA is a safe and effective treatment for benign thyroid nodules in pediatric patients, and can thus serve as an alternative treatment for thyroidectomy.

Ultrasound-Guided Moving Shot Radiofrequency Ablation of Benign Soft Tissue Neoplasm.

Background and Objective: To evaluate the effectiveness of radiofrequency ablation (RFA) using the moving-shot technique for benign soft tissue neoplasm. Materials and Methods: This retrospective study reviewed eight patients with benign soft tissue neoplasm presenting with cosmetic concerns and/or symptomatic issues who refused surgery. Six patients had vascular malformation, including four with venous malformation and two with congenital hemangioma. The other two patients had neurofibroma. All patients underwent RFA using the moving-shot technique. Imaging and clinical follow-up were performed in all patients. Follow-up image modalities included ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging. The volume reduction ratio (VRR), cosmetic scale (CS), and complications were evaluated. Results: Among the seven patients having received single-stage RFA, there were significant volume reductions between baseline (33.3 ± 21.2 cm3), midterm follow-up (5.1 ± 3.8 cm3, p = 0.020), and final follow-up (3.6 ± 1.4 cm3, p = 0.022) volumes. The VRR was 84.5 ± 9.2% at final follow-up. There were also significant improvements in the CS (from 3.71 to 1.57, p = 0.017). The remaining patient, in the process of a scheduled two-stage RFA, had a 33.8% VRR after the first RFA. The overall VRR among the eight patients was 77.5%. No complications or re-growth of the targeted lesions were noted during the follow-up period. Of the eight patients, two received RFA under local anesthesia, while the other six patients were under general anesthesia. Conclusions: RFA using the moving-shot technique is an effective, safe, and minimally invasive treatment for benign soft tissue neoplasms, achieving mass volume reduction within 6 months and significant esthetic improvement, either with local anesthesia or with general anesthesia under certain conditions.

Long-Term Outcomes of Radiofrequency Ablation for Treatment of Cystic Warthin Tumors versus Solid Warthin Tumors.

BACKGROUND: To describe the long-term outcomes of radiofrequency ablation (RFA) of parotid Warthin tumors that have different consistencies and locations. METHODS: We reviewed ten patients with Warthin tumors undergoing RFA treatment from 2016 to 2019. The mean follow-up was 24.3 ± 13.1 months (range 7-42 months). RESULTS: RFA was performed on 11 tumors in ten patients. Cystic tumors (n = 4) had better volume reduction ratios (VRR) than solid tumors (n = 7) at month one and month six, following RFA (77.9% vs. 47.3%, 95.1% vs. 80.6%, respectively, p = 0.003). Tumors in both superficial lobes and deep lobes (n = 7) were larger than tumors in superficial lobes alone (n = 4), though there was no difference in VRR after treatment. All residual tumors were found in superficial lobes. There was no increase in residual tumor size. Every patient showed marked cosmetic improvements, with visible tumors becoming non-palpable masses. CONCLUSIONS: RFA is a safe and effective treatment for Warthin tumors, with better volume reduction in cystic tumors. Results remained satisfying over the long-term for all residual tumors found in superficial lobes, making it easier for re-intervention if necessary.

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.