Comparison of multiparametric magnetic resonance imaging and targeted biopsy with systematic biopsy alone for the diagnosis of prostate cancer: a systematic review and meta-analysis

Importance:
The current diagnostic pathway for prostate cancer (PCa) in patients in whom there is a suspicion of this malignancy includes prostate biopsy. A large proportion of biopsied individuals have either no PCa or low-risk disease that does not require treatment. Unnecessary biopsies may potentially be avoided with pre-biopsy imaging.

Objective:
To compare the performance of systematic trans-rectal ultrasound (TRUS) guided prostate biopsy versus pre-biopsy bi- or multi-parametric MRI followed by targeted +/- systematic biopsy.

Data Sources:
Medline, Embase, Cochrane, Web of Science, clinical trial registries and reference lists of recent reviews were searched to December 2018 for randomized controlled trials (RCTs) using the terms “prostate cancer”, “MRI”.

Study Selection:
RCTs comparing diagnostic pathways including pre-biopsy MRI versus systematic TRUS-guided biopsy in biopsy-naïve men with a clinical suspicion of PCa.

Data Extraction and Synthesis:
Data were pooled using random-effect meta-analysis. Risk of bias was assessed using the revised Cochrane tool. PRISMA guidelines were followed. All review stages were conducted by two reviewers.

Main Outcome(s) and Measure(s):
Detection rate of clinically significant and insignificant PCa, number of biopsy procedures, number of biopsy cores taken, and complications.

Results:
Seven high quality trials (2582 patients) were included. Compared against systematic TRUS biopsy alone, MRI +/- targeted biopsy was associated with an improved detection of clinically significant PCa of 57% (95% confidence interval (CI): 2-141%), a 33% potential reduction in the number of biopsy procedures (95% CI: 23-45%), and a 77% reduction in the number of cores taken per procedure (95% CI: 60-93%). One trial showed reduced pain and bleeding side-effects. Systematical sampling of the prostate in addition to the acquisition of targeted cores did not significantly improve detection of clinically significant PCa compared to systematic biopsy alone.

Conclusions and Relevance:
Pre-biopsy MRI combined with targeted biopsy was superior to systematic TRUS biopsy alone in detecting clinically significant PCa, despite substantial heterogeneity between trials. It was associated with a reduced number of individual biopsy cores taken per procedure, and with reduced side effects, and potentially prevents unnecessary biopsies in some individuals. This evidence supports implementation of pre-biopsy MRI into diagnostic pathways for suspected PCa.