Audit of cancer yields after prostate MRI using both the PI-RADS version 2 and Likert scoring systems.

Aim: To audit diagnostic yields of the updated magnetic resonance imaging (MRI)-directed prostate cancer diagnostic service according to Prostate Imaging - Reporting and Data System (PI-RADS) version 2 and Likert assessments, comparing outcomes of the two scoring systems.

Materials And Methods: Consecutive men with suspected cancer undergoing prostate MRI were included. Biopsy rates and histological diagnostic yields of all and International Society of Urological Pathology Grade Group (ISUP GG) ≥2 cancers according to PI-RADS and Likert assessment categories were documented and outcomes compared.

Results: Of 326 men (91% biopsy naive), 177 (54%) underwent transrectal (n=119) or transperineal (n=58) ultrasound-guided biopsies; 92% with negative MRI avoided immediate biopsies following multidisciplinary team (MDT) review. All cancer and ISUP GG ≥ 2 cancer-detection rates increased with increasing suspicion scores. Prospective paired PI-RADS and Likert scoring was undertaken in 323/326 studies, with 87% concordance rate. High concordance between PI-RADS and Likert scores was observed in negative MRI (99%) and score 5 (96%). High discordance was demonstrated in the PI-RADS 4 group (32% with PI-RADS 4 categories up-risked to Likert 5). All cancer and ISUP GG ≥ 2 cancer detection rates for MRI score ≥3 were 78% and 63%, and for MRI score ≥4 were 75% and 61%, respectively for both PI-RADS and Likert scoring systems.

Conclusions: Most men with negative prostate MRI can avoid immediate biopsies following MDT review. Performance of PI-RADS and Likert scoring systems in clinically significant cancer detection after positive MRI is equivalent. Discordance between PI-RADS and Likert systems seems mostly confined to PI-RADS 4 categories.