Purpose: We evaluated the performance of transrectal ultrasound guided systematic and transperineal template mapping biopsies with a 5 mm sampling frame stratified by the multiparametric magnetic resonance imaging Likert score in the PROMIS (Prostate MR Imaging Study).
Materials and methods: Biopsy naïve men due to undergo prostate biopsy for elevated prostate specific antigen and/or abnormal digital rectal examination underwent multiparametric magnetic resonance imaging, and transperineal template mapping and transrectal ultrasound guided systematic biopsies, which were performed and reported while blinded to other test results. Clinically significant prostate cancer was primarily defined as Gleason 4 + 3 or greater, or a maximum cancer core length of 6 mm or more of any grade. It was secondarily defined as Gleason 3 + 4 or greater, or a maximum cancer core length of 4 mm or more of any grade.
Results: In 41 months 740 men were recruited at a total of 11 centers, of whom 576 underwent all 3 tests. Eight of the 150 men (5.1%) with a multiparametric magnetic resonance imaging score of 1-2 had any Gleason 3 + 4 or greater disease on transrectal ultrasound guided systematic biopsy. Of the 75 men in whom transrectal ultrasound guided systematic biopsy showed Gleason 3 + 3 of any maximum cancer core length 61 (81%) had Gleason 3 + 4, 8 (11%) had Gleason 4 + 3 and 0 (0%) had Gleason 4 + 5 or greater disease. For definition 1 (clinically significant prostate cancer) transrectal ultrasound guided systematic biopsy sensitivity remained stable and low across multiparametric magnetic resonance imaging Likert scores of 35% to 52%. For definition 2 (clinically significant prostate cancer and any cancer) sensitivity increased with higher multiparametric magnetic resonance imaging scores. The negative predictive value varied due to varying disease prevalence but for all cancer thresholds it declined with increasing multiparametric magnetic resonance imaging scores.
Conclusions: In the setting of multiparametric magnetic resonance imaging Likert scores 1-2 transrectal ultrasound guided systematic biopsy revealed Gleason 3 + 4 disease in only 1 of 20 men. Further, for any clinically significant prostate cancer definition transrectal ultrasound guided systematic biopsy had poor sensitivity and variable but a low negative predictive value across multiparametric magnetic resonance imaging scores. Men who undergo transrectal ultrasound guided systematic biopsy without targeting in the setting of a multiparametric magnetic resonance imaging score of 3 to 5 should be advised to undergo repeat (targeted) biopsy.
Keywords: image-guided biopsy; magnetic resonance imaging; predictive value of tests; prostatic neoplasms; ultrasonography.