Comparison of diagnostic accuracy of ACR-TIRADS, American Thyroid Association (ATA), and EU-TIRADS guidelines in detecting thyroid malignancy.

Purpose: This study aims to compare three guidelines according to their diagnostic accuracy in the management of thyroid nodules.

Methods: A total of 540 patients with 597 thyroid nodules were enrolled in this study. Sonographic images were classified and scored with the American Thyroid Association (ATA-2015), American College of Radiology (ACR), and European Thyroid Association (EU) Thyroid Imaging, Reporting, and Data Systems (ACR-TIRADS and EU-TIRADS) guidelines. Fine-needle aspiration biopsy (FNAB) was performed, and cytopathological results were reported with the Bethesda system. Outcomes of these three classification systems were then correlated with Bethesda results.

Results: FNAB procedures revealed a total of 447 benign and 45 malignant nodules. With guideline dedicated FNAB criteria; 38 malignant nodules could have been diagnosed with ATA-2015, which is followed by 34 nodules with ACR-TIRADS, and 31 nodules with EU-TIRADS. Nonetheless, 301 benign nodules would have been biopsied with ATA-2015, 143 benign nodules with ACR-TIRADS, 222 benign nodules with EU-TIRADS. The accuracy rate was found to be highest with ACR-TIRADS (59.93 %); while 55.20 % with ATA-2015 and 51.25 % with EU-TIRADS. The sensitivity and specificity ratios of these guidelines were as follows; ATA-2015 (82.22, 53.47), ACR-TIRADS (48.89, 60.63), and EU-TIRADS (86.67, 48.99). A total of 23 nodules (3.8 %) could not be classified with ATA-2015.

Conclusion: Diagnostic strengths, unnecessary recommended FNAB rates, and categorization capabilities differ among various guidelines. Clinicians and interventional radiologists should keep in mind these features in the management of thyroid nodules.