Independent predictors and ultrasound-based risk stratification for follicular thyroid tumors: a multicenter retrospective study

OBJECTIVE: This retrospective study aimed to investigate the ultrasound characteristics of follicular thyroid adenoma (FTA) and follicular thyroid carcinoma (FTC) and to evaluate the diagnostic efficacy of Follicular Thyroid Imaging Reporting and Data System (F-TIRADS), American College of Radiology (ACR)-TIRADS, and Chinese (C)-TIRADS in differentiating FTC from FTA. MATERIALS AND METHODS: This study included 399 patients with pathologically confirmed FTC or FTA who underwent preoperative thyroid ultrasonography. The ultrasound characteristics and the scores of F-TIRADS, ACR-TIRADS, and C-TIRADS were evaluated. Univariate analysis and multivariate logistic regression were conducted to identify independent predictors of FTC. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), area under the curve (AUC), and p-values were compared. RESULTS: Multivariate logistic regression analysis identified unclear margins, spiculated margins, halo contour, uneven halo thickness, trabecular formation, and multifocal tumors as independent predictors of FTC (odds ratio [OR] = 4.74, 82.68, 0.07, 5.82, 3.26, and 82.09, respectively). The AUC values for the F-TIRADS, ACR-TIRADS, and C-TIRADS were 0.825 (95% confidence interval [CI]: 0.763-0.887), 0.713 (95% CI: 0.645-0.782), and 0.756 (95% CI: 0.685-0.827), respectively. CONCLUSIONS: Ultrasound is valuable in differentiating FTC from FTA, with the F-TIRADS exhibiting superior diagnostic performance compared with those of the ACR-TIRADS and C-TIRADS.