Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus.

We performed a retrospective review of (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) examination to determine the prevalence of thyroid FDG-PET incidentaloma in a patient group evaluated for metastasis of cancer and in a group of healthy subjects who underwent voluntary cancer screening. We also evaluated the risk of malignancy in focal thyroid FDG-PET incidentaloma and its association with standard uptake values (SUVs) (maximum and greater than 0.75 threshold). A total of 1330 subjects underwent FDG-PET for metastasis evaluation (n = 999) and cancer screening (n = 331). Twenty-nine of 1330 subjects (2.2%) showed focal (n = 21) or diffuse (n = 8) thyroid FDG-PET incidentaloma. There was no significant difference in the prevalence of thyroid FDG-PET incidentaloma between the two groups (19 of 999 vs. 10 of 331; P > 0.05). Four of 15 focal incidentalomas (26.7%) whose histological diagnoses were available showed papillary thyroid cancer. The maximum SUV (16.5 +/- 4.70) and greater than 0.75 threshold SUV (14.2 +/- 5.3) of malignant lesions were significantly higher than those of benign tumors (6.5 +/- 3.8 and 4.9 +/- 3.0; P < 0.05). In conclusion, thyroid FDG-PET incidentaloma has prevalence of 2.2%, and its prevalence was not different according to the purpose of the FDG-PET. The focal thyroid FDG-PET incidentaloma carries a high risk of malignancy, especially in cases with high SUVs. Therefore, focal thyroid FDG-PET incidentaloma with high SUVs warrants a pathological diagnostic procedure if it changes a patient's treatment plan or prognosis.

ObjectiveTo assess the efficacy and safety of thyroid radiofrequency (RF) ablation for benign thyroid nodules by trained radiologists according to a unified protocol in a multi-center study.Materials and MethodsFrom 2010 to 2011, 345 nodules from 345 patients (M:F = 43:302; mean age ± SD = 46.0 ± 12.7 years, range = 15–79) who met eligibility criteria were enrolled from five institutions. At pre-ablation, the mean volume was 14.2 ± 13.2 mL (1.1–80.8 mL). For 12 months or longer after treatment, 276 lesions, consisting of 248 solid and 28 predominantly cystic nodules, were followed. All operators performed RF ablation with a cool-tip RF system and two standard techniques (a transisthmic approach and the moving-shot technique). Volume reduction at 12 months after RF ablation (the primary outcome), therapeutic success, improvement of symptoms as well as of cosmetic problems, and complications were evaluated. Multiple linear regression analysis was applied to identify factors that were independently predictive of volume reduction.ResultsThe mean volume reduction at 12 months was 80.3% (n = 276) and at the 24-, 36-, 48-, and 60-month follow-ups 84.3% (n = 198), 89.2% (n = 128), 91.9% (n = 57), and 95.3% (n = 6), respectively. Our therapeutic success was 97.8%. Both mean symptom and cosmetic scores showed significant improvements (p < 0.001). The rate of major complications was 1.0% (3/276). Solidity and applied energy were independent factors that predicted volume reduction.ConclusionRadiofrequency ablation performed by trained radiologists from multiple institutions using a unified protocol and similar devices was effective and safe for treating benign thyroid nodules.

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.