MRI-guided in-bore biopsy for prostate cancer: what does the evidence say? A case series of 554 patients and a review of the current literature.

To review our experience with MRI-guided in-bore prostate biopsy (MRGB) and present a review of the literature on MRGB. A retrospective review of patients presenting for MRGB between 2013 and 2018. Diagnostic and biopsy MRI scans were reviewed to collect data on scan dates, procedure times, characteristics of MRI targets (PI-RADS™ score, target size, ADC value and location). A review of the literature on MRGB for the period 2013-2018 was performed. 607 targets in 554 men were biopsied. Overall and significant cancer detection rate were 80% and 55% at a patient level, and 76 and 59% at the target level, respectively. Prostate cancer (CaP) detection in men with prior negative biopsy was 60% while 50% of men on active surveillance were upgraded to clinically significant disease (CSD). Lesion location did not predict for presence of CaP or CSD. PI-RADS™ score, age and PSAD were predictors of CSD at biopsy on multivariate analysis. Literature review identified 23 reports reporting on MRGB cohorts (~ 4000 patients). Overall cancer detection ranged from 23 to 74% and CSD in 63% overall. CaP detection in PI-RADS™ 3 targets was substantially lower in our series and the literature than for PI-RADS™ 4-5 targets. MRGB in PI-RADS™ 3-5 targets yields high rates of cancer diagnosis. High detection rates are also seen in men with prior negative biopsy and AS cohorts. PI-RADS™ score, age and PSAD can reliably predict CSD detection. The number of published series is small and the role of MRGB in PI-RADS™ 3 targets needs further study.