Ha EJ, et al. Korean J Radiol. 2021 Dec;22(12):2094-2123. https://doi.org/10.3348/kjr.2021.0713

Background The diagnostic performance and unnecessary biopsy rates for evaluation of thyroid nodules varies among the current society guidelines. We hypothesized that diagnostic performance and unnecessary biopsy rates of different guidelines are largely determined by different thyroid size thresholds used as cutoff values that determine when to biopsy a thyroid nodule. Purpose To compare the malignancy risk, diagnostic performance, and unnecessary biopsy rates of three guidelines and evaluate the changes according to the nodule size cutoff for biopsy. Materials and Methods This retrospective study included 3323 consecutive thyroid nodules from 3190 patients between January 2013 and December 2013. US features were reviewed according to the American Thyroid Association (ATA), Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR), and American College of Radiology (ACR) guidelines. The diagnostic performance and unnecessary biopsy rates were calculated. The size cutoff of ATA and KTA/KSThR guidelines was varied and diagnostic performance and unnecessary biopsy rates were calculated and compared by using the generalized estimating equations method. Results A total of 856 (25.8%) thyroid nodules were diagnosed as malignant after surgical excision or biopsy. The highest sensitivity was observed with the KTA/KSThR guideline (93.5% [300 of 321]), followed by the ATA (92.5% [297 of 321]) and ACR guidelines (60.1% [193 of 321]). The highest specificity (75.2% [1216 of 1617], P < .001) with lowest unnecessary biopsy rate (20.7% [401 of 1938]) was observed with the ACR guideline. When the low-suspicion category in the ATA guideline modeled 2.5 cm instead of 1.5 cm as the size for biopsy, the unnecessary biopsy rate decreased to 43.6% (845 of 1938, 2.5-cm cutoff) compared with 55.1% (1068 of 1938, 1.5-cm cutoff) (P < .001). For the KTA/KSThR guidelines, the unnecessary biopsy rate decreased to 36.4% (706 of 1938, 2.5-cm cutoff) compared with 59.5% (1153 of 1938, 1.5-cm cutoff) (P < .001). Conclusion The diagnostic performance and unnecessary biopsy rates of the American Thyroid Association and the Korean Thyroid Association/Korean Society of Thyroid Radiology guidelines are strongly influenced by nodule size cutoff. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Foley in this issue.

Chung SR, et al. Korean J Radiol. 2020 Jul;21:e104. https://doi.org/10.3348/kjr.2019.0983

Background: Several ultrasound (US)-based risk stratification systems have been increasingly used for the optimal management of thyroid nodules. However, there are considerable discrepancies across these systems. This study aimed to summarize and compare the category-based diagnostic performance in the detection of thyroid cancer of different US-based risk stratification systems from four societies: the American College of Radiology-Thyroid Imaging Reporting and Data System (ACR-TIRADS), the American Thyroid Association (ATA), the Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR; K-TIRADS), and the European Thyroid Association (EU-TIRADS). Methods: MEDLINE/PubMed and EMBASE databases were searched to identify original articles investigating the category-based diagnostic performance according to at least one of the following guidelines: ACR-TIRADS, ATA, K-TIRADS, and EU-TIRADS. Pooled sensitivity and specificity were calculated using a bivariate random-effects model. A subgroup analysis on nodules of 1 cm or larger and a meta-regression analysis to identify factors associated with the diagnostic performance were performed. Results: A total of 29 articles including 33,748 thyroid nodules met the eligibility criteria and were included in the analysis. For ACR-TIRADS, the pooled sensitivity and specificity were, respectively, 66% and 91% for category 5 and 95% and 55% for category 4 or 5. For ATA, the pooled sensitivity and specificity were, respectively, 74% and 88% for category 5 and 91% and 64% for category 4 or 5. For K-TIRADS, the pooled sensitivity and specificity were, respectively, 55% and 95% for category 5 and 89% and 64% for category 4 or 5. For EU-TIRADS, the pooled sensitivity and specificity were, respectively, 82% and 90% for category 5 and 96% and 52% for category 4 or 5. Study location, proportion of female patients and malignant nodules, and study design were associated with study heterogeneity. Conclusions: The overall diagnostic performance of the four US-based risk stratification systems was comparable.

Thermal ablation is considered a novel treatment alternative for benign thyroid nodules, with one of the most promising techniques being radiofrequency ablation (RFA). Considering the increasing use of thyroid RFA, some societies have proposed these clinical practice guidelines. Therefore, we systemically reviewed these guidelines for thyroid RFA and compared the similarities and differences between them to identify a standard treatment strategy that has been agreed upon by most societies. We searched studies with human participants that were published in the English language from 1 January 2000 to 2 August 2019 using MEDLINE and EMBASE databases. Studies that included clinical practice guideline of benign thyroid RFA were included. We extracted data on the indication, pre- and post-procedural evaluation, techniques, and informed consent. Of 83 studies, 4 studies were included, and 1 study was added after searching the bibliographies of these articles. Five studies were guidelines developed by the Korean Society of Thyroid Radiology (KSThR), Italian scientific societies, Italian minimally invasive treatment of the thyroid, National Institute for Health and Care Excellence in the United Kingdom, and four professional Austrian thyroid associations. Indications, pre- and post-procedural evaluation, and techniques were similar; however, there were differences in each guideline for RFA of the thyroid gland. Major categories are similar in guidelines. Establishment of international thyroid RFA guidelines for benign thyroid nodules needs in the future.

Ha EJ, et al. Korean J Radiol. 2025 Jan;26(1):10-28. https://doi.org/10.3348/kjr.2024.0963