
Corresponding Author
The use of prostate multiparametric MRI (mpMRI) and targeted biopsy increases detection of clinically significant cancers while decreasing the diagnosis of indolent disease. “One obstacle to broad application of prostate mpMRI is the lack of standardization and training necessary to interpret mpMR images,” wrote Matthew D. Greer, MD, department of radiation oncology at the University of Washington School of Medicine in Seattle. To evaluate agreement among radiologists across experience levels in the detection and assessment of prostate cancer at mpMRI using Prostate Imaging Reporting and Data System version 2 (PI-RADSv2), Greer’s team evaluated a total study population of 163 patients. Of these, 110 underwent prostatectomy after MRI, and 53 evidenced normal MRI findings and transrectal ultrasound–guided biopsy results. Of the nine radiologists representing six countries and eight institutions who volunteered for the study, three had a high level of experience in prostate mpMRI (> 2000 cases in the last two years), three had a moderate level (500–2000 cases in the last two years), and three had a low level of experience (< 500 cases in the last two years). The authors’ results found that sensitivity for index lesions was comparable among all radiologists (average, 92.2%; p = 0.360), but specificity proved experience-dependent. Highly experienced readers had 84.0% specificity versus 55.2% for all others (p < 0.001), suggesting that the decision to perform biopsy be set at a lower threshold for novice prostate mpMRI radiologists and in centers where prostate MRI is an uncommon examination. As Radiology Business noted, “radiologists were blinded to prostate-specific antigen level and previous biopsy results, and providing such information could have improved results.”