Multiparametric Magnetic Resonance/Ultrasound Fusion Prostate Biopsy: Number and Spatial Distribution of Cores for Better Index Tumor Detection and Characterization

Purpose: We evaluated the minimum core number for better index tumor detection to determine the best core site as well as biopsy Gleason score heterogeneity in the same index lesion. The aim was to optimize the highest Gleason score detection.Materials and Methods: A total of 327 patients with negative digital rectal examination underwent magnetic resonance imaging/transrectal ultrasound fusion targeted biopsy for elevated/rising prostate specific antigen and/or 1 or more detectable lesions on multiparametric magnetic resonance imaging after a previous negative standard biopsy. Depending on the diameter of each index lesion (8 or less, or greater than 8 mm) 4 or 6 cores, respectively, were taken according to a well determined sequence.Results: Of the patients 166 (50.7%) had prostate cancer, including 79 (47.6%) with an 8 mm or less index lesion and 87 (52.4%) with a greater than 8 mm index lesion. Of patients with an index tumor 8 mm or less 7 (8.9%) had 1, 31 (39.2%) had 2, 27 (34.2%) had 3 and 14 (17.7...