Real-World Outcomes Following the Implementation of ACR TI-RADS for Evaluation of Thyroid Nodules

Detection of thyroid nodules is increasing. The American College of Radiology Thyroid Image Reporting and Data System (ACR TI-RADS) purports to decrease unnecessary thyroid fine needle aspiration (FNA) in selected retrospective groups. Limited reports of real-world performance suggest otherwise. This large series compares our real-world outcomes pre- and post-implementation of ACR TI-RADS for thyroid ultrasound (US) reporting.

ACR TI-RADS was adopted at our tertiary institution in 2018. In this retrospective observational study, all patients undergoing thyroid US were divided into pre-TIRADS (2014-2017) and post-TIRADS (2019-2022) groups. We analyzed US, FNA, surgery rates, pathological outcomes, and cost data. A subset of post-TIRADS patients was analyzed for US findings and adherence to ACR TI-RADS recommendations.

Our study included 13,156 patients. Post-TIRADS, the total number of thyroid US decreased (9112 vs. 10,811). Also, the post-TIRADS group had a significantly larger proportion of patients with only one US performed (70.8% vs. 62.1%, p < 0.001). Both groups had a similar number of FNAs and surgeries performed. The surgically proven malignancy rate, median tumor size, and stage were similar. The total healthcare cost of all these procedures was higher in the post-TIRADS group ($4,772,158.00) versus the pre-TIRADS group ($4,280,081.98). In the subset analysis, adherence to ACR TI-RADS was noted in 444/635 patients (69.9%, 95% CI 66.2%-73.4%).

While the implementation of ACR TI-RADS has led to a reduction in follow-up thyroid US, the rate of thyroid FNAs and surgery at our institution has not reduced. Further confirmatory research in other populations in the real world is required.