Safety and Efficacy of Radiofrequency Ablation for Nonfunctioning Benign Thyroid Nodules in Children and Adolescents in 14 Patients over a 10-Year Period.

PURPOSE: To evaluate the efficacy and safety of radiofrequency (RF) ablation for nonfunctioning benign thyroid nodules in children and adolescents. MATERIALS AND METHODS: Fourteen pediatric patients (10 female, 4 male; mean age 15.7 ± 2.3 years, range 12-19 years) with nonfunctioning benign thyroid nodules (mean longest diameter 3.7 ± 1.1 cm, range 2.0-5.6 cm) treated with the use of RF ablation from 2005 to 2015 were evaluated. The inclusion criteria for RF ablation therapy were (i) age <20 years, (ii) benign cytological confirmation by ≥2 separate fine-needle aspiration or core needle biopsies, (iii) pressure symptoms or cosmetic problems caused by thyroid nodules, (iv) absence of any suspicious feature as determined with the use of ultrasound (US), (v) normal serum levels of thyroid hormone and thyrotropin, and (vi) follow-up of >6 months. RF ablation was performed with the use of an RF generator and an 18-gauge internally cooled electrode. RF ablation was performed under local anesthesia without conscious sedation or general anesthesia. Changes in nodules on follow-up US, changes in symptomatic and cosmetic scores, and complications arising during or after RF ablation were evaluated. RESULTS: Mean follow-up period was 36.9 ± 21.7 months (range 6-69 months). At last follow-up visits, mean longest nodule diameter and volume had decreased significantly (3.7 ± 1.1 cm vs 1.4 ± 0.9 cm and 14.6 ± 13.3 mL vs 1.7 ± 4.4 mL; P < 0.001). Both cosmetic and compressive symptoms significantly improved (3.8 ± 0.6 vs 1.4 ± 0.6 and 3.4 ± 1.0 vs 0.1 ± 0.4; P < 0.001). The mean number of ablation sessions was 2.1 ± 1.2 (range 1-5 sessions) and no major complication was encountered during or after RF ablation. CONCLUSIONS: RF ablation might be a safe and effective treatment modality for nonfunctioning benign thyroid nodules in children and adolescents.

US Fine-Needle Aspiration Biopsy for Thyroid Malignancy: Diagnostic Performance of Seven Society Guidelines Applied to 2000 Thyroid Nodules.

Purpose To compare the diagnostic performance of ultrasonography (US)-based fine-needle aspiration biopsy (FNAB) criteria from seven international societies in the detection of thyroid malignancy. Materials and Methods This study included a total of 2000 consecutive thyroid nodules (≥1 cm) in 1802 patients with final diagnoses from January 2010 to May 2011. US features of the thyroid nodules were retrospectively reviewed and were classified according to the categories defined by the seven international society guidelines. The diagnostic performance of US-based FNAB criteria in the detection of thyroid malignancy and unnecessary FNAB rates were calculated and compared by using a generalized estimating equation method. Results Of the 2000 thyroid nodules, 1546 (78.3%) were benign and 454 (22.7%) were malignant, with papillary carcinoma comprising 85.5% of all malignancies. The Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR) (94.5%), National Comprehensive Cancer Network (NCCN) (92.5%), and American Thyroid Association (ATA) (89.6%) guidelines were more sensitive than those of the American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME) (80.4%), American College of Radiology (ACR) (74.7%), French Society of Endocrinology (FSE) (72.7%), and Society of Radiology in Ultrasound (SRU) (70.9%) (P < .001), while the latter guidelines had higher specificity (P < .001). The rate of unnecessary FNAB was lowest with the ACR guidelines (25.3%), followed by the FSE (29.1%), AACE/ACE/AME (32.5%), SRU (45.2%), ATA (51.7%), NCCN (54.0%), and KTA/KSThR (56.9%) guidelines. Conclusion Because the diagnostic performance of US-based FNAB criteria varies according to the individual international society guidelines, clinicians should be aware of the strengths and weaknesses of US-based FNAB criteria in the management of thyroid nodules. © RSNA, 2018 Online supplemental material is available for this article.

Analysis of postoperative ultrasonography surveillance after total thyroidectomy in patients with papillary thyroid carcinoma: a multicenter study.

Background In papillary thyroid carcinoma (PTC) patients, postoperative ultrasonography (US) surveillance is recommended at intervals of six or 12 months even though evidence is weak. Purpose To determine the optimal interval of postoperative US surveillance in patients after total thyroidectomy for the treatment of PTC using multicenter data. Material and Methods A total of 1400 patients from seven tertiary hospitals who underwent total thyroidectomy for treatment of PTC were included. Based on a retrospective review of clinical and pathologic results, multiple factors were analyzed according to recurrence/persistence or no recurrence/persistence. In recurrence/persistence group, the interval and number of follow-up US sessions in the initial detection of recurrence/persistence were investigated. Results Of the 1400 patients, 115 (8.2%) showed tumor recurrence/persistence on follow-up US. Of 115 recurrence/persistence cases, 89 (77.4%) were initially detected on US: nodal recurrence/persistence (n = 92), non-nodal recurrence/persistence (n = 22), and both (n = 1). Among the clinical and pathologic factors, only tumor size and N stage were significant predictors for recurrence/persistence. In the recurrence/persistence group, the mean interval and number of follow-up US sessions in the initial detection of recurrence/persistence was 22.3 ± 16.8 months and 2.2 ± 1.9, respectively. Approximately two-thirds of recurrence/persistence cases (76/115, 66.1%) were detected in follow-up US within two years after total thyroidectomy. Conclusion In PTC patients after total thyroidectomy, the optimal interval of the first US follow-up may be one to two years after thyroid surgery, and the appropriate number of postoperative US surveillance sessions within the first five years may be only one or two.

Factors influencing the outcome from ultrasonography-guided fine-needle aspiration of benign thyroid cysts and partially cystic thyroid nodules: A multicenter study.

PURPOSE: The effect of ultrasonography (US)-guided fine-needle aspiration (US-FNA) for the collapse of benign cystic thyroid nodules is still unclear. This study aimed to assess the positive response rate following US-FNA of the cystic component of thyroid cysts and of partially cystic thyroid nodules (PCTNs), and to evaluate the factors influencing the outcome. METHODS: From June to December 2013, seven radiologists at seven institutions prospectively performed US-FNA on 320 cystic thyroid nodules in 320 patients. Among them, 179 underwent at least one follow-up US examination following US-FNA of the cystic component at each institution by the same radiologist. A variety of factors, including US features of cystic thyroid nodules, the characteristics of the aspirates, and the follow-up US findings, were analyzed. RESULTS: Of 179 cystic thyroid nodules, there were 53 thyroid cysts and 126 PCTNs. Of 179 cystic thyroid nodules, no malignancies were detected. On follow-up US, the mean size reduction rate of the cystic component was 31.9%, and 102 out of 179 thyroid nodules (57.0%) were assigned to the response group. On univariate analysis, the degree of aspiration and time interval between US-FNA and the final follow-up US showed the significant differences between the response and no response groups. On multivariate analysis, the only factor that influenced the outcome was the nodule type. The cystic component's positive response rate after simple aspiration was higher in the thyroid cysts than in the PCTNs. CONCLUSIONS: US-FNA may be effective at collapsing the cystic components of benign thyroid cysts and PCTNs.

Treatment Efficacy and Safety of Ethanol Ablation for Thyroglossal Duct Cysts: A Comparison with Surgery.

OBJECTIVE: To compare the efficacy and safety of ethanol ablation (EA) for thyroglossal duct cyst (TGDC) against surgery. METHODS: This study included 345 patients (289, surgery; 56, EA) treated for TGDC at four institutions between May 2005 and June 2014. Surgery (whole surgery and Sistrunk operation which is the current standard surgical method) and EA were compared with respect to the treatment failure and complication rates. The cost of EA and surgery was also compared. The Cox regression hazard model and linear regression were used for the adjustment of covariates. RESULTS: EA demonstrated higher treatment failures (19.6% vs. 2.4%, p < 0.001[whole surgery] and 1.2%, p = 0.004 [Sistrunk operation]), but fewer complications (1.8% vs. 10.0%, p = 0.04 [whole surgery] and 10.2%, p = 0.06 [Sistrunk operation]), and lower cost (₩423,801 vs. ₩1,435,707 [whole surgery]) than surgery. EA achieved 85.7% of treatment success up to second session. The mean volume reduction rate after EA was 82.3% at last follow-up. Young age and EA were correlated with treatment failure (p = 0.01 and 0.001, respectively). CONCLUSION: Both surgery and EA had acceptable treatment efficacy in the management of TGDC. Although there is a higher likelihood of treatment failure with EA, it has a better safety profile than surgery. KEY POINTS: • Both surgery and ethanol ablation show acceptable treatment efficacy for TGDC. • Considering treatment failure, surgery manages TGDC more effectively than EA. • EA is safer than surgery and presents no major complications. • EA could be an alternative treatment for TGDC in selected patients.

Radiofrequency ablation of small follicular neoplasms: initial clinical outcomes.

BACKGROUND: In thyroid gland, radiofrequency ablation (RFA) has been applied to both recurrent cancers and benign nodules, although, according to the American Thyroid Association (ATA) and the Korean Society of Thyroid Radiology (KSThR) guidelines, surgery is the first-line treatment for follicular neoplasm. However, it has been argued that follicular neoplasm with lower risk of malignancy can be managed by close follow-up. In this study, we evaluated the effectiveness of RFA of small follicular neoplasms, examining reductions in volume and related clinical problems, and making observations over long-term follow-up. METHODS: We evaluated 10 follicular neoplasms in 10 patients who were treated with RF ablation between 2009 and 2011. A RF generator and an 18-gauge internally cooled electrode were used to perform complete ablation of the whole nodules. Changes in nodules or ablated zones on follow-up ultrasound, and complications during and after RF ablation were evaluated. RESULTS: The mean follow-up period was 66.4 ± 5.1 months (range: 60-76 months). In eight patients, single session of RF ablation was sufficient, while two patients required two sessions. There was a significant reduction in the mean volume (99.5 ± 1.0%) of lesions, with eight ablated lesions (8/10, 80%) disappearing completely on follow-up. No recurrences were found in any ablated zones at last follow-up. Transient mild neck pain (n = 6) occurred during the procedure without requiring any medication. CONCLUSION: In addition to active surveillance, RF ablation may be an effective and safe alternative for the management of patients with small (<2 cm) follicular neoplasm suspected on thyroid biopsy and who strongly refuse surgery.

Radiofrequency ablation of low-risk small papillary thyroidcarcinoma: preliminary results for patients ineligible for surgery.

PURPOSE: The purpose of this study is to retrospectively evaluate the outcomes of radiofrequency ablation (RFA) of low-risk small papillary thyroid carcinomas (PTCs) in patients who were ineligible for surgery. MATERIALS AND METHODS: Between 2005 and 2009, six PTCs (mean diameter, 0.92 cm; range, 0.6-1.3 cm) in six patients were treated with RFA by three radiologists in two hospitals. The inclusion criteria for this study were (1) pathologically confirmed PTC without cytological aggressiveness, (2) single PTC without extrathyroidal extension, (3) no metastatic tumours and (4) ineligibility for surgery. RFA was performed using a radiofrequency generator and an 18-gauge internally cooled electrode. The medical records were reviewed and analysed, focussing on the procedural profiles of RFA, symptoms and complications during and after RFA, and changes in tumours on follow-up ultrasonography. RESULTS: Before and after RFA, the results of thyroid function tests were normal in all patients. During 48.5 ± 12.3 months (range, 36-65 months) of follow-up, along with a significant reduction in the mean volume (98.5 ± 3.3%), four ablation zones (4/6, 66.7%) completely disappeared. Two ablation zones exhibited only small calcified residues with nearly complete disappearance of the corresponding non-calcified solid portions, and in one of them, malignant cells were absent as assessed by fine-needle aspiration and core-needle biopsy. Transient hypertension with mild headache (n = 1) and mild neck pain (n = 1) developed during the procedure and subsided without any treatment. CONCLUSION: Besides surgery and active surveillance, which are conflicting currently used management plans, RFA might represent an effective and a safe alternative for managing low-risk small PTCs, especially in patients ineligible for surgery.

ANALYSIS OF POSTOPERATIVE ULTRASONOGRAPHY SURVEILLANCE AFTER HEMITHYROIDECTOMY IN PATIENTS WITH PAPILLARY THYROID MICROCARCINOMA: A MULTICENTER STUDY.

OBJECTIVE: The optimal follow-up interval for postoperative ultrasonography (US) surveillance after hemithyroidectomy in patients with papillary thyroid microcarcinoma (PTMC) is unclear. The purpose of this study was to evaluate the prevalence of tumor recurrence/persistence and to investigate the appropriateness of postoperative US surveillance in PTMC patients who underwent hemithyroidectomy. METHODS: Our institutional review board approved this retrospective study. From 2000 to 2011, 800 patients underwent hemithyroidectomy as treatment for PTMC, as well as at least one session of postoperative follow-up US, at four different institutions. The images and data of postoperative US surveillance were retrospectively investigated by experienced radiologists at each institution. Based on the follow-up US and histopathologic results, locoregional tumor recurrence/persistence was determined. RESULTS: Of the 800 patients, 82.2% had T1a, 17.8% had T3, and none had T1b, T2, T4a, or T4b disease; 6.9% had unknown N stage, 80.1% had N0, 13% had N1a, and none had N1b, based on histopathology. There were also no cases of distant metastasis after hemithyroidectomy. Among the patients, 784 (98%) showed no tumor recurrence/persistence, and 16 (2%) showed locoregional tumor recurrence/persistence during the follow-up period. The patients differed in the number of sessions and the intervals of postoperative follow-up US. In the 16 patients with tumor recurrence/persistence, the mean interval of postoperative follow-up US since the first US detection of tumor recurrence/persistence was 42.9 ± 25.9 months. All recurrence/persistence cases were subcentimeter. CONCLUSION: Postoperative US surveillance at 1-or 2-year intervals may be unnecessary because of the very low recurrence rate in PTMC. ABBREVIATIONS: EMR = electronic medical record; PTMC = papillary thyroid microcarcinoma; TNM = tumor, node, metastasis; US = ultrasonography; US-FNA = ultrasonography-guided fine-needle aspiration.

Postoperative ultrasonography surveillance in patients with follicular thyroid carcinoma: a multicenter study.

OBJECTIVE: This study aimed to evaluate the locoregional recurrence rate of follicular thyroid carcinoma (FTC) and to assess the appropriate frequency of postoperative ultrasonography (US) surveillance for detecting tumor recurrence. METHODS: The review boards of the seven participating institutions approved this study. From 2000 to 2011, 186 patients underwent at postoperative US at least once; US was performed by experienced radiologists at each institution. Based on the US and histopathological results, locoregional tumor recurrence was assessed. RESULTS: The T stages of the 186 patients were T1a (8.1%), T1b (21.5%), T2 (39.8%), T3 (30.6%), T4a (0%), and T4b (0%). The N stages were unknown (24.2%), N0 (71.5%), N1a (3.2%), and N1b (1.1%), and the M stages unknown (29.6%), M0 (66.1%), and M1 (4.3%). Tumors recurred in only 6 (3.2%) patients during the follow-up period over 5 years. Among them, no patients showed the initial suspicion of recurrences on routine follow-up US. The session number and interval of postoperative US differed significantly between patients with recurrence and those without recurrence. The mean interval of postoperative follow-up US at the first detection time of tumor recurrence was 37.5 ± 18.5 months (range 9-62 months). Significantly more FTCs were at an advanced N and M stage in the recurrence group than in the non-recurrence group (p < 0.05). CONCLUSIONS: Routine postoperative US surveillance may be unnecessary for detecting tumor recurrence after thyroid surgery in FTC patients.

Radiofrequency Ablation for Iatrogenic Thyroid Artery Pseudoaneurysm: Initial Experience.

Eight iatrogenic thyroid pseudoaneurysms (ITPAs) after thyroid biopsy are reported. The mean ITPA diameter was 7.2 mm (range 4 to 12 mm). Ultrasound (US)-guided compression was initially performed at the neck of the ITPA in all cases. Among them, 4 ITPAs persisted (50%) in which radiofrequency (RF) ablation was performed. Mean RF ablation time and power were 13.5 seconds (range 5 to 24 seconds) and 20 W (range 10 to 50 W), respectively. All 4 cases were treated with RF ablation without any complications.

The ultrasonography features of hyalinizing trabecular tumor of the thyroid gland and the role of fine needle aspiration cytology and core needle biopsy in its diagnosis.

BACKGROUND: Hyalinizing trabecular tumor (HTT) of the thyroid gland is a rare, benign neoplasm of follicular cell origin. Misdiagnosis of HTT as either papillary or medullary thyroid carcinoma after fine-needle aspiration (FNA) may lead to unnecessary surgery. PURPOSE: To evaluate the ultrasonography (US) findings of HTT of the thyroid gland and the role of FNA cytology and core needle biopsy (CNB) in its diagnosis. MATERIAL AND METHODS: Data from 24 patients with a histopathological diagnosis of HTT between January 2000 and May 2013 were retrospectively analyzed. US findings were categorized according to shape, margin, orientation, echogenicity, composition, calcification, and vascularity. Cytologic and histologic results of FNA, CNB, and surgery were reviewed. RESULTS: US revealed the following tumor features: oval-to-round (24/24), solid (22/24), smooth margin (21/24), hypoechoic or marked hypoechogenicity (18/24), and peri- and/or intranodular vascularity (17/17). Malignant US features such as marked hypoechogenicity (n = 7) and a spiculated margin (n = 3) were also observed. Final confirmation was by surgery in 22 patients and by CNB in two patients. All 19 patients who underwent FNA were initially misdiagnosed, including 12 with malignancies and five with atypia of undetermined significance. All four patients who underwent CNB were correctly diagnosed with HTT. The histology of CNB specimens suggested HTT, which was confirmed by immunostaining of MIB-1. CONCLUSION: HTT should be suspected when the cytological diagnosis of papillary thyroid carcinoma is made after FNA without malignant US findings. CNB could prevent unnecessary surgery for HTT.

Detection of thyroid pyramidal lobe by ultrasound versus computed tomography: a single-center study.

OBJECTIVE: The prevalence and features of the thyroid pyramidal lobe (TPL) on computed tomography (CT) have been reported, but no ultrasound (US) study has been found. The purposes of the current study were to assess the sonographic prevalence and features of TPLs and to compare the US and CT parameters of TPLs. METHODS: From November 2012 to February 2013, a total of 160 patients who were scheduled for surgical treatment of thyroid cancers and follicular neoplasms were enrolled. A single radiologist prospectively evaluated the presence and features of TPLs on preoperative thyroid US, noting the size, location, degree of continuity with the main thyroid gland, and superior extent of each TPL. On a different day, the same radiologist retrospectively evaluated CT findings in the same patients from a picture archiving and communication system. RESULTS: Ultrasound revealed TPLs in 82 cases (50.6%) and CT revealed TPLs in 96 cases (59.3%). Thyroid pyramidal lobes predominantly originated from the left thyroid lobe on both US (34/82, 41.5%) and CT (40/96, 41.7%). The mean length, anteroposterior diameter, transverse diameter, and volume of the TPLs were 20.9 mm, 2.0 mm, 5.8 mm, and 268.6 mm on US and 22.8 mm, 1.9 mm, 6.1 mm, and 344.0 mm on CT, respectively. When CT findings were used as the reference standard, the sensitivity, specificity, positive and negative predictive values, as well as accuracy of US for detecting TPLs were 82.3, 95.3, 93.3, 78.2, and 87.5%, respectively. CONCLUSIONS: Like neck CT, thyroid US may be useful in evaluating TPLs.

Single-session treatment of benign cystic thyroid nodules with ethanol versus radiofrequency ablation: a prospective randomized study.

PURPOSE: To compare volume reduction of single-session ethanol ablation (EA) and radiofrequency (RF) ablation for cystic thyroid nodule treatment. MATERIALS AND METHODS: All patients gave written informed consent to participate in this prospective institutional review board-approved study. From May 6, 2010, to August 8, 2011, in this single-institutional, noninferiority trial, 50 patients, each with a single cystic thyroid nodule, were randomly assigned to EA (25 patients; mean age for women, 45.7 years, and for men, 37.5 years) or RF ablation (25 patients; mean age for women, 45.1 years, and for men, 43.7 years) treatment. Internal fluid was aspirated prior to EA or RF ablation. Primary end point was the volume reduction ratio (percentage) at 6-month follow-up; the noninferiority margin was chosen as -8% (EA minus RF ablation). Secondary end points included therapeutic success rate, improvement of symptoms and cosmetic problems, and number of major complications. Analysis was performed primarily in intention-to-treat manner. A one-sided 95% confidence interval (CI) for the mean difference in volume reduction ratio 6 months after treatment was calculated to test for noninferiority. Subsequent superiority comparison of EA with RF ablation on a condition of establishment of the noninferiority of EA to RF ablation was preplanned and used two-sided 95% CI of the outcome difference. RESULTS: The mean volume reduction was 96.9% in EA and 93.3% in RF ablation (n = 21 for each) (difference, 3.6%; lower bound of the one-sided 95% CI of the difference, 1.2%), thus demonstrating the noninferiority of EA to RF ablation. Two-sided 95% CI of the outcome difference was 0.7% to 6.5%, demonstrating significant superiority of EA to RF ablation. All patients demonstrated therapeutic success (P > .99). Mean symptom and cosmetic scores showed no significant difference in either group (P = .806 and P = .682, respectively). There were no major complications (P > .99). CONCLUSION: EA may be the first-line treatment modality for cystic thyroid nodules, which has comparable therapeutic efficacy to, but is less expensive than, RF ablation.

[Effective and Safe Application of Radiofrequency Ablation for Benign Thyroid Nodules]. / ì–‘ì„±ê°‘ìƒì„ ê²°ì ˆì— 대한 íš¨ê³¼ì ì´ê³ ì•ˆì „í•œ ê³ ì£¼íŒŒì ˆì œì˜ ì ìš©.

Radiofrequency ablation (RFA) has been a representative, non-surgical treatment for benign thyroid nodules that cause cosmetic problems or compression symptoms. The procedure of RFA should be performed effectively and safely. This review discusses the patient selection, pre-procedure evaluation and planning, principles, devices, techniques, and complications with reference to the guidelines and research on thyroid RFA. In particular, this review will devote to introduce RFA techniques and to provide practical help in the implementation of this procedure.

Parenchymal microcalcifications in the thyroid gland: Clinical significance and management strategy.

This study is firstly, to investigate the presence of microcalcification among the patients who underwent thyroid ultrasound and biopsy and to evaluate the incidence of intrathyroid lymphatic spread and cervical lymph node metastasis of thyroid cancer with thyroid microcalcifications. Also, we compared the diagnostic performance between fine needle aspiration (FNA) and core needle biopsy (CNB) for assessing parenchymal microcalcifications in the thyroid gland. We retrospectively assessed total 66 patients with thyroid microcalcifications on ultrasound. The histopathologic characteristics of the surgical specimens considered as the gold standard for diagnosing malignancy. Patients with surgically proven malignancy were evaluated for multifocality, intrathyroid lymphatic spread in the opposite lobe, or cervical lymph node metastasis. Among the 66 confirmed patients, 53 patients had malignant lesions (80.3%) and 13 patients had benign lesions (19.7%). The pathologic results of the 44 patients who underwent total thyroidectomy. Among them, 33 patients (75%) showed multifocality, 30 patients (68.2%) showed intrathyroid lymphatic tumor spread. CNB was performed on 41 patients, and FNA was performed on 54 patients. Both CNB and FNA were performed on 29 patients. There were no statistical differences in terms of diagnostic performance between CNB and FNA. Thyroid microcalcifications demonstrate a high prevalence of malignancy. Both CNB and FNA demonstrate similar diagnostic accuracies.

[Training of Radiofrequency Ablation for Thyroid Nodules in Korea: Current and Future Perspective]. / 국내의 ê°‘ìƒì„ ê³ ì£¼íŒŒ ì ˆì œìˆ ì— 대한 교육: 현황 및 미래 ì „ë§.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. In Korea, RFA for thyroid nodules was first performed in 2002, and a large population study was published in 2008. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed its first recommendations for RFA in 2009, which were revised in 2012 and 2018. The KSThR guideline was the first guideline for RFA of thyroid nodules worldwide and has become a guideline for physicians to perform thyroid RFA in Korea and other countries around the world. These guidelines have contributed significantly to the establishment and widespread use of RFA worldwide. In addition, since 2015, the KSThR has conducted intensive hands-on courses depending on the level of the participants. In this article, the authors introduce the history of eduction for RFA conducted by the KSThR and describe the learning curve of RFA and current training programs in Korea, along with future directions for training programs.

Complications encountered in the treatment of benign thyroid nodules with US-guided radiofrequency ablation: a multicenter study.

PURPOSE: To evaluate clinical aspects and imaging features of complications encountered in the treatment of benign thyroid nodules with radiofrequency (RF) ablation. MATERIALS AND METHODS: Institutional review board approval was obtained for this retrospective study, and informed consent was waived. From June 2002 to September 2009, 1459 patients underwent RF ablation of 1543 thyroid nodules with an RF system with internally cooled electrodes at 13 thyroid centers, which were members of Korean Society of Thyroid Radiology. Numbers and types of major and minor complications were assessed. RESULTS: The authors observed 48 complications (3.3%), 20 major and 28 minor. The major complications were voice changes (n = 15), brachial plexus injury (n = 1), tumor rupture (n = 3), and permanent hypothyroidism (n = 1). The minor complications were hematoma (n = 15), skin burn (n = 4), and vomiting (n = 9). All patients recovered spontaneously except for one with permanent hypothyroidism and one who underwent surgery. CONCLUSION: Although the complication rate of RF ablation is low, various complications may occur; comprehension of complications and suggested technical tips may prevent complications or properly manage those that occur.

Diagnostic accuracy of fine-needle aspiration versus core-needle biopsy for the diagnosis of thyroid malignancy in a clinical cohort.

OBJECTIVES: To retrospectively compare the accuracy of fine-needle aspiration (FNA) and core-needle biopsy (CNB) for the diagnosis of thyroid malignancy METHODS: We evaluated the results of FNA and CNB in 555 consecutive thyroid nodules with final diagnoses (malignancy 318, benign 237). All patients underwent FNA and CNB simultaneously for each nodule. We assessed the sensitivity, specificity and accuracy of FNA, CNB and FNA/CNB for the diagnosis of thyroid malignancy. RESULTS: The sensitivity of FNA, CNB and FNA/CNB for thyroid malignancy was 68.6%, 86.8% and 90.6%, specificity 100%, 99.2% and 99.2%, and accuracy 82.0%, 92.1% and 94.2%, respectively. The sensitivity and accuracy of CNB or FNA/CNB for thyroid malignancy were significantly higher than those of FNA (P < 0.001). Compared with CNB alone, FNA/CNB was more accurate for thyroid malignancy only in small nodules less than 1 cm (P < 0.001). CONCLUSIONS: Our clinical cohort data demonstrated that CNB was more accurate for the diagnosis of thyroid malignancy than FNA, and FNA/CNB was more accurate than CNB alone in small thyroid nodules. CNB will play a complementary role in optimal surgical decision-making and the management of thyroid nodules. KEY POINTS: • CNB was more accurate for the diagnosis of malignancy than FNA. • Combined FNA/CNB was more accurate than CNB alone in small thyroid nodules. • CNB should play at least a complementary role in managing thyroid nodules.

Optimum first-line treatment technique for benign cystic thyroid nodules: ethanol ablation or radiofrequency ablation?

OBJECTIVE: The purpose of this article is to compare the efficacy and safety of ethanol ablation and radiofrequency ablation (RFA) used as treatment of benign cystic thyroid nodules. MATERIALS AND METHODS: Fifty-seven patients (44 women and 13 men) with benign cystic nodules (cystic portions > 90%) inducing pressure symptoms or cosmetic problems were treated with ethanol ablation (n = 36) or RFA (n = 21). Ethanol ablation was performed using 16- or 18-gauge needles with 95-99% ethanol, and RFA used a cooled-electrode RFA system and 17- or 18-gauge internally cooled electrodes. Of nine viscous nodules, five were treated with ethanol ablation and four with RFA, with all except for one nodule in the RFA group being treated only after evacuation of internal colloid material. Nodule volume, symptom score (0-10), cosmetic score (1-4), and complications were evaluated before and after treatment. RESULTS: Both ethanol ablation and RFA resulted in significant decreases in nodule volume (p < 0.001), symptom score (p < 0.001), and cosmetic score (p < 0.001). There were no between-group differences in mean volume reduction (p = 0.15), decreases in symptoms (p = 0.53), cosmetic scores (p = 0.69), or therapeutic success rate (p = 0.61). However, the mean number of treatment sessions was significantly lower in the ethanol ablation than in the RFA group (p = 0.026). No serious complications were encountered in either group. CONCLUSION: Ethanol ablation yielded similar results with fewer treatment sessions compared with RFA. Because ethanol ablation is also less expensive and simpler to perform than RFA, our findings suggest that ethanol ablation, rather than RFA, should be the first-line treatment technique for benign predominantly cystic thyroid nodules.