INTRODUCTION: This study aims to evaluate diagnostic performance of the American College of Radiology Thyroid Imaging Reporting and Data System (ACR-TIRADS) in the Turkish adult population.
METHODS: A total of 422 thyroid nodules of 368 patients (103 males, 265 females; mean age 46.43 years; range, 18 to 81 years) diagnosed by fine needle aspiration biopsy (FNAB) or surgical pathology were retrospectively analyzed. The decisions for FNABs were mostly made by the experts of our hospital without using the ACR-TIRADS. The observers assessed five different aspects of thyroid nodules: echogenicity, shape, composition, margin, and echogenic foci. Nodules with 0 points were categorized as TR1, 2 points as TR2, 3 points as TR3, 4-6 points as TR4, and ≥7 points as TR5. The sensitivity, specificity, and diagnostic accuracy of ACR and the proportion of benign nodules and malignant nodules to be biopsied according to the ACRTIRADS were calculated.
RESULTS: The ACR-TIRADS identified 47 of 54 malignant nodules and identified 264 of 368 benign nodules yielding 73.6% diagnostic accuracy. Using the ACR-TIRADS would have spared 64.1% of benign nodules from FNAB. Of 54 malignant nodules, 23 were to be biopsied, 30 to be followed, and one malignant nodule was not planned to be biopsied or followed according to the ACR-TIRADS recommendations.
DISCUSSION AND CONCLUSION: Despite its robustness in sparing a substantial number of benign nodules from FNAB, the use of ACR-TIRADS would prevent 55.5% of malignant nodules from FNAB. We suggest that FNAB threshold levels of the ACR-TIRADS should be extensively reviewed by the Turkish radiologists, endocrinologists, general surgeons, and ear, nose and throat surgeons before integrating the system to their daily practice.