The accuracy of multiparametric MRI in men with negative biopsy and elevated PSA level—Can it rule out clinically significant prostate cancer?

Abstract

PurposeTo assess the performance of multiparametric magnetic resonance imaging (mp-MRI) in patients with previous negative transrectal ultrasound (TRUS) guided prostate biopsy. Materials and methodsFifty-four patients with at least 1 previous negative TRUS prostate biopsy underwent mp-MRI in the form of T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging. This was followed by transperineal template systematic prostate biopsies. Analysis was done based on 2 sectors per prostate, right and left (108 sectors out of 54 prostates). mp-MRI was scored using an ordinal scale 1 to 5 based on the suspicion of the presence of clinically significant disease. We used 6 different definitions for clinically significant disease and tested the performance of mp-MRI at each single definition. ResultsMedian age was 64 (range, 39–75), median PSA level was 10 (range, 2–23), and median number of biopsies was 45 (range, 21–137). Cancer of any volume and any grade was detected in 34 of 54 (63%) patients. mp-MRI accuracy at detection of clinically significant cancer using University College London (UCL) definition 2 (any Gleason score of 4 or maximum cancer core length of ≥4mm or both) showed sensitivity of 76%, specificity of 42%, positive predictive value of 38%, and negative predictive value of 79%. For a different definition of significant tumor (UCL definition 1; dominant Gleason score 4 or maximum cancer core length ≥6mm or both), the sensitivity was 90%, specificity 42%, positive predictive value 26%, and negative predictive value 95%. Conclusionsmp-MRI showed good performance at both detection and ruling out clinically significant disease, according to the definition used. mp-MRI can then be used as a triage test in the population with persistently elevated or rising PSA levels to select patients that can avoid unnecessary prostate biopsy.