The Accuracy of Prostate Magnetic Resonance Imaging Interpretation: Impact of the Individual Radiologist and Clinical Factors

Objective: To compare test performance of multiparametric magnetic resonance imaging (mpMRI) for detection of prostate cancer between individual radiologists using the Prostate Imaging Reporting and Data System (PI-RADS) and to identify clinical factors that may predict test performance. Materials and Methods: We examined our database of consecutive men who received prostate mpMRI prior to biopsy between September 2014 and December 2016 (n = 459). Test performance (eg, sensitivity, specificity, positive predictive value [PPV] and negative predictive value) were defined with PI-RADS classification 4 or 5 considered test positive and Gleason score ≥7 on biopsy from any targeted core considered outcome positive. Multivariate logistic regression was performed to identify clinical variables that affect test performance. Results: No significant differences in test performance were found among individual radiologists. Prior biopsy (odds ratio [OR] 0.10, P =.01), radiologist experience >500 prostate mpMRI (OR 0.18, P =.04), transition zone location (OR 0.10, P =.04), and posterior location (OR 0.04, P =.03) were predictors of diminished sensitivity. Location of the mpMRI lesion in the TZ was a predictor of improved specificity (OR 2.53, P =.04). Increasing age (OR 1.07, P <.01) and prostate-specific antigen (OR 1.10, P <.01) predicted increased PPV, while prior biopsy predicted decreased PPV (OR 0.50, P <.01). Conclusion: Although variation exists in test performance among individual radiologists using PI-RADS, significant differences were not observed. Additional prostate mpMRI experience was not beneficial in improving accuracy of interpretation. Nonmodifiable patient variables—including prostate lesion location, prior biopsy history, prostate-specific antigen, and age—are predictive of prostate mpMRI test performance.