Who needs a fine‐needle biopsy? A comparison of the ATA and ACR TI‐RADS guidelines in a single‐centre retrospective study

Abstract

AbstractThe 2015 American Thyroid Association (ATA) and 2017 American College of Radiology: Thyroid Imaging, Reporting and Data System (ACR TI‐RADS) guidelines are two popular guidelines adopted to stratify sonographic risk of malignancy for thyroid nodules, and to select cases for fine‐needle aspiration (FNA). To understand the test performance of the two systems in predicting thyroid malignancy, 164 thyroidectomy cases performed in a regional hospital in Hong Kong between January 2021 and June 2022 were reviewed. Sonographic images of the index nodule in each case were retrospectively classified into different risk categories using the ATA and ACR TI‐RADS guidelines, respectively, followed by retrieval of cytological and pathological results, for comparison. The index nodule was proven malignant in 26.8% of cases in the final pathology. There was a strong and positive correlation between the ATA and ACR TI‐RADS risk categories assignment (rs = .931, p < .001). Recommending FNA according to the ATA had a better sensitivity for malignancy than using the ACR TI‐RADS (81.8% vs 72.7%), at the expense of a lower specificity (10.8% vs 40.8%). The sensitivity for malignancy of both systems could be further improved if all fluorodeoxyglucose (FDG)‐avid nodules were investigated with FNA regardless of sonographic features and size. There was a statistically significant association between “nodules with FDG avidity and nodules recommended for FNA by the ACR TI‐RADS guideline” and an eventual malignant thyroid nodule (p = .002).