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.