Direct magnetic resonance imaging-guided biopsy of the prostate: lessons learned in establishing a regional referral center

MRI-targeted biopsy of the prostate appears to have the potential to reduce the high rates of underdiagnosis and overdiagnosis associated with the current diagnostic standard of transrectal ultrasound guided systematic biopsy. Direct or "in bore" MRI-guided biopsy is one of the three methods for MRI-targeted core needle sampling of suspicious, generally Pi-RADS 4 or 5, foci within the prostate, and our early experience suggests the approach demonstrates substantial utility and promise in the care of patients with prostate cancer. We performed direct MRI-guided biopsies in 50 patients within 19 months of establishing the first referral center for this service in our region. Our preliminary results indicate the service can be easily grown due to unmet demand, primarily in patients with a negative traditional systematic biopsy but with a concerning focus at MRI (30 of 50; 60%). Other applications include evaluation of patients who are on active surveillance (n=14; ten upgraded to higher Gleason score at MRI-guided biopsy), who are biopsy naïve (n=5; all positive at MRI-guided biopsy), or post focal therapy (n=1; positive for recurrent tumor at MRI-guided biopsy). With careful patient selection and technique, we have achieved a favorable overall positive biopsy rate of 73% (37 of 50), with 84% (31 of 37) positive biopsies demonstrating Gleason score 7 or greater disease. Large multicenter comparative trials will be required to determine the relative accuracy and appropriate utilization of direct MRI guided biopsy in the care pathway of patients with known or suspected prostate cancer.