A correlation study between thyroid imaging report and data systems and the Bethesda system for reporting thyroid cytology with surgical follow-up - an ultrasound-trained cytopathologist's experience

Introduction: Thyroid Imaging Reporting and Data Systems (TI-RADS) including a modified system (M TI-RADS) and American College Radiology (ACR) TI-RADS are introduced. Correlation studies between both TI-RADSs and The Bethesda System for Reporting Thyroid Cytology (TBSRTC) for Ultrasound-guided fine-needle aspiration (US-FNA) cases with surgical follow-up (SFU) are presented. Materials and Methods: Three hundred and forty six thyroid US-FNA cases performed at the US-FNA clinic of Stony Brook University Hospital by an Ultrasound-trained interventional Cytopathologist between December 1, 2014 to February 28, 2018 were reviewed. All ultrasound images from 346 cases were evaluated and assigned M TI-RADS scores based on ultrasound features present in Table 1. One hundred and fifty four cases from Dcember 1, 2014 to February 28, 2016 were assigned scores using ACR TI-RADS.TBSRTC category along with SFU data was collected and correlated with both TI-RADS scores by using Pearson's correlation coefficient (r). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy for M TI-RADS and TBSRTC were also calculated using SFU diagnosis as a gold standard. McNemar test was applied to evaluate the significance of the difference between M TI-RADS and TBSRTC. Results: Based on 346 thyroid nodules studied, the overall r-value between M TI-RADS scores and TBSRTC categories is 0.465. The r-values between Composition, Echogenicity, Shape, Margin, Echogenic foci, the summary points, and the converted TR level of ACR TI-RADS and TBSRTC are 0.145, 0.042, 0.259, 0.310, 0.405, and 0.379, respectively. Fifty (14.5%) cases have SFUs. Considering TI-RADS 5&6 and TBSRTC 5&6 as positives, and TI-RADS 2 and TBSRTC 2 as negatives, the Sensitivity, Specificity, PPV, NPV, and accuracy are 96%, 53%, 76%, 89%, 79% for TI-RADS vs 100%, 93%, 96%, 100%, 97% for TBSRTC, respectively (P =.038). The data for indeterminate cases are summarized. Conclusion: Both TI-RADSs could be helpful to a moderate degree. M TI-RADS appeared to correlate to TBSRTC slightly better than that of ACR TI-RADS. TBSRTC is significantly more accurate than M TI-RADS for the majority of determined cases.