Agreement between ACR TI-RADS and EU TI-RADS scoring systems in the diagnosis of 473 thyroid nodules from a single-center in Brazil.

Abstract Objectives This study compares two ultrasound-based risk-stratification systems in malignancy risk assessment of thyroid nodules and the clinical applicability of these guidelines in Brazil. Methods We retrospectively reviewed the ultrasound findings of 314 patients (473 thyroid nodules) who underwent fine needle aspiration (FNA) biopsy and/or surgery between February 2018 and March 2019. All nodules were classified using two systems: The Thyroid Imaging, Reporting, and Data System of the American College of Radiology (ACR-TIRADS) and the TIRADS of the European Thyroid Association (EU-TIRADS). Both risk-stratification system was analyzed. We identify diagnostic predictive values that yielded optimal sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC). Results Of the 473 nodules, all underwent FNA, and 332 nodules had histopathology performed. The agreement between the ACR-TIRADS and EU-TIRADS results and between cytology and histopathology findings was 92.6% (Kappa = 0.84) and 86.7% (Kappa = 0.73), respectively. The area under the curve (AUC) of the ACR-TIRADS and EU-TIRADS were 0.871 and 0.828, respectively (p Conclusion ACR-TIRADS and EU-TIRADS had good diagnostic performances. However, most aspirated nodules did not follow the TIRADS indication; thus, the overuse of FNA as a diagnostic tool was observed.