A prospective study of cancer detection rates following early repeat imaging and biopsy of PI-RADS 4 and 5 regions of interest exhibiting no clinically significant prostate cancer on prior biopsy

Introduction: We aimed to determine cancer detection rates following early repeat multiparametric magnetic resonance imaging (mpMRI) and biopsy of Prostate Imaging-Reporting and Data System (PI-RADS), v2.1 4 and 5 regions of interest (ROI) exhibiting no clinically significant prostate cancer (csPCa) on prior biopsy and to identify predictors for these missed csPCa. Methods: Between January 2019 and August 2020, 36 men with 38 PI-RADS 4 or 5 ROI with no evidence of csPCa (defined as Gleason grade group [GGG] >1) on prior MRI fusion target biopsy (MRFTB) + systematic biopsy (SB) were invited to participate in the present prospective study. All men underwent repeat mpMRI and persistent PI-RADS >2 ROI were advised to undergo repeat MRFTB+SB. Cancer detection rates of any and csPCa were determined. Relative risk was calculated to analyze association of baseline variables with the finding of csPCa on repeat biopsy. Results: Of the 38 initial PI-RADS 4 and 5 ROI, on followup mpMRI, 14 were downgraded to PI-RADS 1/2 and, per protocol, did not undergo repeat biopsy and; eight (33%), 12 (50%), and four (17%) were PI-RADS 3, 4, and 5 respectively. Of these 24 persistently suspicious mpMRI ROI, 20 (83%) underwent repeat biopsy and six (30%), six (30%), and eight (40%) were benign, GGG 1, and GGG >1, respectively. Only prostate-specific antigen ≥10 ng/mL was a predictor for missed csPCa. Conclusions: Our prospective study supports a recommendation for early repeat mpMRI of all PI-RADS 4 or 5 ROI exhibiting no csPCa, with repeat MRFTB + SB of persistent PI-RADS >2 ROI .