Purpose: The aim of our study was to validate and compare TIRADS ACR 2017 and ATA 2015 risk stratification for thyroid papillary carcinoma, in our patient population, specifically pertaining to reduction of unnecessary biopsies.
Patients and Methods: This prospective study cohort was comprised of 237 nodules in 190 patients who underwent fine needle aspiration (FNA) biopsy between May, 2018 and March, 2019 at one institution.
Informed consent was signed before the procedure by all patients.
All patients over 18 years old who were referred for thyroid nodule FNA from outpatient and inpatient clinics were included.
Statistical analysis was performed only on those nodules that according to the TIRADS and/or ATA guidelines were eligible for FNA, and included a total of 198 nodules.
The study was approved by the institutional review board of our institution.
The ultrasound examinations were performed using a Linear 5-12 MHz transducer (Epiq 7, Philips Medical Systems). Images of the biopsied nodule were obtained.
The nodule to undergo FNA was chosen according to TIRADS ACR and/or the ATA risk criteria.
Data collected, included nodule characteristics with corresponding TIRADS and ATA grading and cytological results using Bethesda scoring for each nodule.
Results: A hundred and ninety-eight nodules were included in the statistical analysis.
Of those, 13 had a positive cytology result of Bethesda 6 or 5.
A hundred and eighty-five nodules had a cytology result other than Bethesda 6 or 5.
A hundred seventy-four nodules had cytology results other than Bethesda 5 or 6 when applying ATA criteria, and 105 nodules when applying TIRADS criteria.
We found an agreement between the two criteria methods in 58.8% (116/198) of the cases.
The specificity was 5.9% (11/185) for ATA criteria and 37.8% (70/185) for TIRADS.
The sensitivity was 100% (13/13) for ATA and 92% (12/13 ) for TIRADS.
Conclusions: Our study showed that application of ACR TIRADS criteria can significantly reduce the number of US guided FNA performed on benign nodules compared to ATA criteria.
