Validation of dominant and secondary sequence utilization in PI-RADS v2 for classifying prostatic lesions.

Introduction: To assess the secondary sequence rule in The Prostate Imaging Reporting Data System (PI-RADS) version 2 by comparing the detection of Grade group 1+ (GG1+) and 2+ (GG2+) cancers in PI-RADS 3, an upgraded PI-RADS 4, and true (non-upgraded) PI-RADS 4 targets.

Materials And Methods: We analyzed a total of 589 lesions scored as PI-RADS 3 or 4 obtained from 434 men who underwent mpMRI-US fusion biopsy from September 2015 to November 2017 for evaluation of GG1+ and GG2+ prostate cancer. PI-RADS 4 lesions were differentiated into those that were 'upgraded' to PI-RADS 4 based on the secondary sequence and those that were 'true' PI-RADS 4 based on the dominant sequence.