Fine needle aspiration biopsy indications for thyroid nodules: compare a point-based risk stratification system with a pattern-based risk stratification system

Objectives We aim to compare the diagnostic performance to assess thyroid nodules and reliability for recommending fine needle aspiration biopsy (FNAB) between American College of Radiology thyroid image reporting and data system (ACR TI-RADS) and American Thyroid Association (ATA) guidelines. Methods In total, this retrospective study included 1001 consecutive thyroid nodules in 918 patients from May 2016 to December 2017. US features of the thyroid nodules, including composition, echogenicity, shape, margins, echogenic foci, and size, were reviewed and were classified according to ACR TI-RADS and ATA guidelines, respectively. The diagnostic performance to assess thyroid nodules and reliability for recommending fine needle aspiration biopsy were compared between ACR TI-RADS and ATA guidelines. Results Of the 1001 thyroid nodules, 609 (60.8%) were benign and 392 (39.2%) were malignant. The sensitivity, specificity, PPV, NPV, and accuracy were 96.7%, 77.3%, 73.3%, 97.3%, and 84.9%, respectively, for ACR TI-RADS and 99.2%, 16.1%, 43.2%, 97.0%, and 48.7%, respectively, for ATA guidelines. AUC of ACR TI-RADS was significantly greater than ATA guidelines (0.935 (0.918, 0.949) vs 0.884 (0.862, 0.903), p < 0.001). Biopsy yield of malignancy, biopsy rate of malignancy, and unnecessary FNAB rate were 59.5%, 91.3%, and 40.5%, respectively, for ACR TI-RDS and 38.5%, 97.4%, and 61.5%, respectively, for ATA guidelines. Conclusions ACR TI-RADS was more accurate than ATA guidelines for differentiating malignant thyroid nodules from benign nodules and more reliable than ATA guidelines for recommending thyroid nodules for FNAB.