Can multi-parametric magnetic resonance imaging and prostate-specific antigen density accurately stratify patients prior to prostate biopsy?

Objective: This study examines the diagnostic accuracy of multi-parametric magnetic resonance imaging (mpMRI) in a high-volume centre to potentially stratify patients prior to prostate biopsy. Methods: All biopsy naïve patients who had mpMRI prostate and transperineal biopsy of prostate (TPBx) in 2017 and 2018 were included. There were no exclusion criteria. All patients, regardless of the mpMRI result, underwent systematic template biopsy under general anaesthesia with cognitive target biopsy if indicated. Clinicopathological data were extracted from medical records. The primary outcome was the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of mpMRI prostate in the detection of prostate cancer (PCa) compared with template TPBx. Results: In total, 140 patients were included. Overall, 57.1% had a positive biopsy. A higher Prostate Imaging-Reporting and Data Systems (PI-RADS) score was associated with a higher risk of diagnosing clinically significant PCa (International Society of Urological Pathology (ISUP) ⩾ 2) ( p < 0.001). The sensitivity, specificity, NPV, and PPV of mpMRI in detecting clinically significant PCa with a PI-RADS ⩾ 3 lesion, was 95% (95% confidence interval (CI) 83.0–99.3%), 41% (95% CI 31.3–51.3%), 95.3% (95% CI 84.2–99.4%) and 39.2% (95% CI 29.4–49.6%), respectively. Combining this with prostate-specific antigen density (PSAD) of <0.15 further improved the NPV to 100% (86.3–100). Binomial logistic regression to understand the effects of PSA, DRE and PI-RADS score on predicting clinically significant PCa (ISUP ⩾ 2) found increasing PSA (odds ratio (OR) 1.06, (95% CI 1.00–1.11, p = 0.022)) and PI-RADS (OR 3.17, (95% CI 1.94–5.18, p < 0.001)) to be significant predictors. Malignant DRE was not a significant predictor ( p = 0.087). Conclusion: This study demonstrates that the high sensitivity and NPV of mpMRI combined with PSAD may play a pivotal role in stratifying men for prostate biopsy and help avoid biopsy and its associated morbidity in select patients. Level of Evidence: 2b (Oxford Centre for Evidence-Based Medicine: Levels of Evidence)