In-bore magnetic resonance-guided transrectal biopsy for the detection of clinically significant prostate cancer

Purpose: To determine the safety and efficacy of in-bore magnetic resonance-guided prostate biopsy (MRGB) for detection of clinically significant disease (CSD) in untreated men with known or suspected prostate cancer (PCa). Methods: 512 patients underwent multiparametric magnetic resonance imaging (Mp-MRI) followed by MRGB at one of three centers in this IRB-approved, HIPAA-compliant, retrospective study. Exclusion criteria were prior prostate cancer therapy and incomplete Mp-MRI (n = 51). Patients (n = 461) were analyzed in two sub-cohorts: no prior PCa (NP) (n = 381) and active surveillance (AS) (n = 80). Detection rates of PCa and CSD (Gleason Score >= 3 + 4) were calculated and compared among subcohorts and by Mp-MRI assessment grade. Logistic regression was performed to identify predictors for detection of PCa and CSD. Results: Mean patient age was 66 years, median prostate-specific antigen (PSA) was 7.5 ng/mL, and median prostate volume was 54 cc. A mean of 1.7 targets was sampled per gland. Significant adverse events (urosepsis and hematuria with obstruction) occurred in 1% (5/461). Overall PCa detection rates were 51% per patient (233/461) and 37% per lesion (282/757). 65% (151/233) of men with detected PCa had CSD. Per-patient PCa detection rates in the NP and AS subcohorts were 47% (178/381) and 69% (55/80), respectively, significantly higher in the AS group (p < 0.001). CSD was detected in 10% (47/451), 43% (96/225) and 84% (68/81) of lesions with Mp-MRI assessment grades of 3, 4, and 5, respectively. Older age, higher PSA, and lower prostate volume predicted MRGB detection of CSD (OR 1.07 and p = 0.003, OR 1.1 and p = 0.014, and OR 0.98 and p = 0.032, respectively). Conclusions: In-bore MRGB is safe and high yield for detection of CSD.