Methodological considerations in assessing the utility of imaging in early prostate cancer

An imaging-based pathway, including multiparametric MRI (mpMRI) and magnetic resonance (MR) targeted biopsy, is being increasingly proposed to overcome the shortcomings of the current pathway, based on transrectal ultrasound (TRUS) random biopsy. The purpose of this review is to look at the methodological considerations that need to be addressed prior to widespread adoption of this pathway.

Novel diagnostic tests should be evaluated in a stepwise fashion with respect to key points: technical accuracy, place in the clinical pathway, diagnostic accuracy, impact on patient outcome and cost-effectiveness. The combination of mpMRI and MR-targeted biopsy has been shown to be superior to TRUS biopsy with regard to most of these key points. mpMRI has the characteristics to be employed as a triage test. MR-targeted biopsy has been consistently shown to be superior to TRUS biopsy in terms of detection of clinically significant disease, utility and efficiency. Before widespread adoption, it is essential to standardize these tests and verify the reproducibility of their performance.

Comparative diagnostic studies are consistently in favour of an imaging-based pathway. Once standardization and reproducibility will be verified, it is likely that TRUS biopsy will be implemented, or replaced by mpMRI and MR-targeted biopsy.