PROMIS was registered on (NCT01292291), and its design has been discussed elsewhere [6]. In brief, this was a multicentre study in which biopsy-naïve men with PSA ≤15 ng/mL underwent prebiopsy 1.5 T mpMRI, followed by a combined biopsy procedure under general anaesthetic. The combined procedure consisted of 5 mm transperineal template mapping (TPM) biopsy followed by standard systematic TRUS-guided biopsy. Each test was performed and reported by clinicians blinded to other results. For this work, only men enrolled at University College London Hospital (UCLH) were considered (n = 235).

Ethical approval for PROMIS was granted by the National Research Ethics Service Committee London (Ref: 11/LO/0185).