Optimising the number of cores for magnetic resonance imaging‐guided targeted and systematic transperineal prostate biopsy

OBJECTIVES: To assess cancer detection rates of different target‐dependent transperineal magnetic resonance (MR)/ultrasonography (US) fusion‐guided biopsy templates with reduced number of systematic cores. PATIENTS AND METHODS: Single‐centre outcome of transperineal MR/US fusion‐guided biopsies of 487 men with a single target MR imaging (MRI) lesion, prospectively collected between 2012 and 2016. All men underwent transperineal targeted biopsy (TB) with two cores, followed by 18–24 systematic sector biopsies (SB) using the Ginsburg protocol. Gleason score ≥7 prostate cancer detection rates for two‐core TB, four‐core extended TB (eTB), 10‐ to 20‐core saturation TB (sTB) including cores from sectors adjacent to the target, and 14 core ipsilateral TB (iTB) were compared to combined TB+SB. RESULTS: Cancer was detected in 345 men and Gleason score 7–10 cancer in 211 men. TB alone detected 67%, eTB 76%, sTB 91% and iTB 91% of these Gleason score 7–10 cancers. In the subgroup of 33 men (7% of cohort) with an anterior >0.5 mL highly suspicious MRI lesion and a prostate volume ≤45 mL, four‐core eTB detected 31 of 32 cancers (97%) and all 26 Gleason score 7–10 cancers. CONCLUSION: sTB detected Gleason score 7–10 cancer in 25% more of the men than a two‐core TB approach, and in almost as many men (91%) as the 20–26‐core combined TB+SB, while needing only 10–20 cores. A four‐core extended TB may suffice for large, highly suspicious anterior lesions in small or slightly enlarged prostates.