How Many Cores Should be Obtained During Saturation Biopsy in the Era of Multiparametric Magnetic Resonance? Experience in 875 Patients Submitted to Repeat Prostate Biopsy

Abstract

ObjectiveTo evaluate the number of needle cores combined with multiparametric magnetic resonance imaging (mpMRI) findings needed to diagnose all clinically significant cases of prostate cancer (csPCa) in men subject to transperineal saturation biopsy (SPBx; 30 cores). MethodsFrom January 2016 to June 2019, 875 men (median age 63 years) underwent repeat SPBx (median 30 cores) for the suspicion of cancer. All of the patients underwent for the first time 3.0 Tesla pelvic mpMRI before SPBx, and the lesions with Prostate Imaging-Reporting and Data System category ≥3 underwent additional transperineal-targeted fusion prostate biopsies (TPBx). ResultsStageT1c PCa was found in 306/875 (34.5%), and 222/306 (72.5%) of them were classified as csPCa. SPBx missed 2/222 (1%) csPCa with International Society of Urologic Pathology Grade Group (GG) 3. TBPx missed 33/222 (14.9%) csPCa (21 vs 12 cases were GG1 vs GG3). The initial 20 needle SPBx cores obtained from the peripheric (16 cores) and anterior gland (4 cores) diagnosed all of the 222 (100%) csPCa only missing 84/129 (65.1%) indolent PCa thus presenting diagnostic accuracy, sensitivity, and specificity equal to 83.1%, 100%, and 65.1%, respectively. ConclusionIn men subject to mpMRI and/or TPBx, a maximum of 20 systematic transperineal needle cores detected all cases of csPCa and minimized the diagnosis of indolent cancers.