To determine the predictive value of ACR-TIRADS in detecting malignancy in thyroid nodules.

This is a retrospective, multi-center, cross-sectional analysis of patients who underwent ultrasound and thyroidectomy at three Cordillera Consortium hospitals between January 2019 and December 2021. Ultrasound reports were reviewed and correlated with histopathology reports to determine features associated with malignancy.

A study of 117 patients with thyroid nodules found significant differences in ACR-TIRADS subcategories. The risk of malignancy for TIRADS categories 1, 2, 3, 4, and 5 were 10%, 9.5%, 21.9%, 43.9%, and 76.97%, respectively. ACR-TIRADS demonstrated a high sensitivity of 92.1% and negative predictive value (NPV) of 90.3% as a rule-out test, and a specificity of 96.2% with a positive predictive value (PPV) of 76.9% as a rule-in test using TIRADS 5 as malignant. Correct classification of malignant nodules increased by cut-off value with the highest at 73.5% at the ≥5 cut-off value. Discussion: Thyroid nodules were more common in females under 55 years old. Certain sonographic features of thyroid nodules, such as being solid or predominantly solid, hypoechoic, lobulated/irregular, and having punctate echogenic foci, were associated with malignancy. The risk of malignancy at Cordillera Consortium hospitals was notably higher in this study. The ACR-TIRADS test yielded results consistent with previous studies, with TR 1 and 2 indicating benign nodules and TIRAD 3-5 indicating malignant nodules.

Due to a higher risk of malignancy, it is recommended to be more aggressive in performing biopsies for thyroid nodules at Cordillera Consortium hospitals. ACR-TIRADS is a reliable screening tool and is recommended as a confirmatory test (TIRADS 5) for thyroid malignancy. Biopsies are still recommended for TIRADS 3, 4, and 5 nodules to avoid unnecessary procedures and confusion among surgeons.