Combining Thyroid Imaging Report and Data System (TIRADS) and Afirma Genomic Sequencing Classifier (GSC) for...

This study retrospectively assessed the ultrasound parameters in Bethesda category III thyroid nodules accompanied by a diagnostic Afirma genomic sequencing classifier (GSC) testing result and surgical/clinical follow-up, and investigated whether combining ultrasound and GSC classifications could improve risk stratification of the atypia of undetermined significance (AUS) nodules.

Data including radiologic Thyroid Imaging Report and Data System (TIRADS) score, concurrent GSC test results, and surgical/clinical follow-up were collected from patients with thyroid nodules meeting the study criteria. The distribution of TIRADS scores was compared between GSC-suspicious versus GSC-benign cohorts, as well as between malignant and benign nodules. The diagnostic performance of the GSC was compared between TIRADS 5 and TIRADS < 5 cohorts.

The study consisted of 322 AUS nodules. Compared to the GSC-benign cohort, the GSC-suspicious cohort had a greater proportion of TIRADS 5 nodules (34% vs. 24%, P = 0.045), a lower proportion of TIRADS 1-3 nodules (20% vs. 30%, P = 0.048), and a higher average TIRADS score (4.12 vs. 3.92, P = 0.03). Compared to the benign cohort (histologically and/or clinically benign), the malignant cohort (histologically malignant) showed a higher proportion of TIRADS 5 nodules (52% vs. 24%, P = 0.004). The mean TIRADS score was also significantly higher in the malignant cohort compared to the benign cohort (4.36 vs. 3.92, P = 0.015). GSC testing demonstrated a significantly higher positive predictive value in the TIRADS 5 AUS nodules than that of TIRADS< 5 nodules (39% vs. 17%, P = 0.016).

A GSC-suspicious result combined with TIRADS 5 significantly improved the positive predictive value, thereby enhancing risk stratification in AUS thyroid nodules, while other diagnostic parameters remained unchanged.