PI-RADS version 2.1 scoring system is superior in detecting transition zone prostate cancer: a diagnostic study

Purpose The studies comparing the versions 2 vs. 2.1 of the Prostate Imaging Reporting and Data System (PI-RADS) are rare. This study aimed to evaluate whether PI-RADS version 2.1 is superior in detecting transition zone prostate cancer in comparison with PI-RADS version 2. Methods This was a diagnostic study of patients with prostate diseases who visited the Urology Department of The Second Affiliated Hospital of Soochow University and underwent a magnetic resonance imaging (MRI) examination between 03-01-2016 and 10-31-2018. The images originally analyzed using PI-RADS version 2 were retrospectively re-analyzed and scored in 2019 according to the updated PI-RADS version 2.1. The kappa and receiver operating characteristic (ROC) curves were used. Results For Reader 1, compared with PI-RADS version 2, version 2.1 had higher sensitivity (85% vs. 79%,P = 0.03), lower specificity (65% vs. 83%,P < 0.001), and lower area under the curve (AUC) (0.749 vs. 0.809,P < 0.001). For Reader 2 (first attempt), compared with PI-RADS version 2, version 2.1 had lower specificity (67% vs. 91%,P < 0.001) and lower AUC (0.702 vs. 0.844,P < 0.001). For Reader 2 (second attempt), compared with PI-RADS version 2, version 2.1 had higher sensitivity (88% vs. 78%,P < 0.001) and lower specificity (77% vs. 91%,P < 0.001). The kappa between the two attempts for Reader 2 was 0.321. Conclusion These results suggest that PI-RADS version 2.1 might improve the detection of prostate cancers in the transition zone compared with PI-RADS version 2 but that it might results in higher numbers of biopsies because of lower specificity.