Accuracy of the magnetic resonance imaging pathway in the detection of prostate cancer: a systematic review and meta-analysis

Background: Although magnetic resonance imaging and subsequent targeted biopsy (‘MRI pathway’) have been widely adopted in routine clinical practice, it is still a common practice to perform systematic biopsy concurrently, because the accuracy of the MRI pathway is yet to be fully defined. This systematic review of the literature assessed the sensitivity of the MRI pathway for detecting clinically significant prostate cancer. Methods: Multiple databases were searched up to May 2017 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement for studies assessing the accuracy of MR-guided biopsy (MRGB) compared to a reference standard which consisted of both MRGB and systematic biopsy with at least 20-cores. The primary outcome was the sensitivity of detecting clinically significant prostate cancer defined as Gleason ≥7 disease. Results: A total of 15 studies met the predefined inclusion criteria. Overall, studies were assessed to be of low quality with inadequate blinding of personnel, which could introduce performance and detection bias. The calculated summary sensitivity of the MRI pathway was 78.3% [95%CI 75.0–81.4%]. There was moderate heterogeneity between the included studies (I ² = 36%). Subgroup analysis was performed based on clinical setting, the strength of MRI magnet and mode of image fusion as factors but no interaction was identified between any of the subgroups. No publication bias was identified. Conclusion: The MRI pathway cannot yet be solely relied upon to diagnose clinically significant disease and hence additional systematic sampling should still be performed during the biopsy procedure.