Background Prostate MRI is used widely in clinical care for guiding tissue sampling, active surveillance, and staging. The Prostate Imaging Reporting and Data System (PI-RADS) helps provide a standardized probabilistic approach for identifying clinically significant prostate cancer. Despite widespread use, the variability in performance of prostate MRI across practices remains unknown. Purpose To estimate the positive predictive value (PPV) of PI-RADS for the detection of high-grade prostate cancer across imaging centers. Materials and Methods This retrospective cross-sectional study was compliant with the HIPAA. Twenty-six centers with members in the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel submitted data from men with suspected or biopsy-proven untreated prostate cancer. MRI scans were obtained between January 2015 and April 2018. This was followed with targeted biopsy. Only men with at least one MRI lesion assigned a PI-RADS score of 2-5 were included. Outcome was prostate cancer with Gleason score (GS) greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2). A mixed-model logistic regression with institution and individuals as random effects was used to estimate overall PPVs. The variability of observed PPV of PI-RADS across imaging centers was described by using the median and interquartile range. Results The authors evaluated 3449 men (mean age, 65 years ± 8 [standard deviation]) with 5082 lesions. Biopsy results showed 1698 cancers with GS greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2) in 2082 men. Across all centers, the estimated PPV was 35% (95% confidence interval [CI]: 27%, 43%) for a PI-RADS score greater than or equal to 3 and 49% (95% CI: 40%, 58%) for a PI-RADS score greater than or equal to 4. The interquartile ranges of PPV at these same PI-RADS score thresholds were 27%-44% and 27%-48%, respectively. Conclusion The positive predictive value of the Prostate Imaging and Reporting Data System was low and varied widely across centers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Milot in this issue.
Radiology. 2020 Apr 21 [Epub ahead of print]
Antonio C Westphalen, Charles E McCulloch, Jordan M Anaokar, Sandeep Arora, Nimrod S Barashi, Jelle O Barentsz, Tharakeswara K Bathala, Leonardo K Bittencourt, Michael T Booker, Vaughn G Braxton, Peter R Carroll, David D Casalino, Silvia D Chang, Fergus V Coakley, Ravjot Dhatt, Steven C Eberhardt, Bryan R Foster, Adam T Froemming, Jurgen J Fütterer, Dhakshina M Ganeshan, Mark R Gertner, Lori Mankowski Gettle, Sangeet Ghai, Rajan T Gupta, Michael E Hahn, Roozbeh Houshyar, Candice Kim, Chan Kyo Kim, Chandana Lall, Daniel J A Margolis, Stephen E McRae, Aytekin Oto, Rosaleen B Parsons, Nayana U Patel, Peter A Pinto, Thomas J Polascik, Benjamin Spilseth, Juliana B Starcevich, Varaha S Tammisetti, Samir S Taneja, Baris Turkbey, Sadhna Verma, John F Ward, Christopher A Warlick, Andrew R Weinberger, Jinxing Yu, Ronald J Zagoria, Andrew B Rosenkrantz
From the Departments of Radiology and Biomedical Imaging (A.C.W., R.J.Z.), Urology (A.C.W., P.R.C.), and Epidemiology and Biostatistics (C.E.M.) and the Clinical and Translational Science Institute (C.E.M.), University of California, San Francisco, 505 Parnassus Ave, M-392, Box 0628, San Francisco, CA 94143; Department of Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, Pa (J.M.A., R.B.P.); Departments of Radiology and Radiological Sciences (S.A., V.G.B) and Urologic Surgery (S.A.), Vanderbilt University Medical Center, Nashville, Tenn; Departments of Radiology (A.O.) and Urology (N.S.B), University of Chicago, Chicago, Ill; Departments of Radiology (J.O.B) and Nuclear Medicine (J.J.F.), Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands; Departments of Diagnostic Radiology (T.K.B., D.M.G), Interventional Radiology (S.E.M.), and Urology (J.F.W.), University of Texas MD Anderson Cancer Center, Houston, Tex; Diagnósticos da América S/A, Rio de Janeiro, Brazil (L.K.B); and Department of Radiology, Fluminense Federal University of Rio de Janeiro, Rio de Janeiro, Brazil (L.K.B.); Department of Radiology, University of California, San Diego, San Diego, Calif (M.T.B., M.E.H.); UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, Calif (P.R.C.); Department of Radiology, Northwestern University, Feinberg School of Medicine, Chicago, Ill (D.D.C., A.R.W.); Department of Radiology, University of British Columbia, Vancouver, Canada (S.D.C., R.D.); Department of Diagnostic Radiology, Oregon Health Science University, Portland, Ore (F.V.C., B.R.F.); Department of Radiology, University of New Mexico Health Sciences Center, Albuquerque, NM (S.C.E., B.S., J.B.S.); and Department of Radiology, Mayo Clinic, Rochester, Minn (A.T.F.). Joint Department of Medical Imaging, University Health Network-Mount Sinai Hospital-Women's College Hospital, Toronto, Canada (M.R.G., S.G.); Department of Radiology, University of Wisconsin School of Medicine and Public Health, Madison, Wis (L.M.G.); Departments of Radiology (R.T.G.) and Surgery (R.T.G., T.J.P.), Duke University Medical Center and Duke Cancer Institute, Durham, NC; Department of Radiological Sciences and Urology, University of California, Irvine, Orange, Calif (R.H.); Virginia Commonwealth University School of Medicine, Richmond, Va (C.K.); Department of Radiology and Center for Imaging Sciences, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea (C.K.K.); Department of Radiology, University of Florida College of Medicine, Jacksonville, Fla (C.L.); Department of Radiology, Weill Cornell Medicine, New York, NY (D.J.A.M.); Department of Radiology, University of Colorado at Denver, Denver, Colo (N.U.P.); Molecular Imaging Program (B.T.) and Urologic Oncology Branch (P.A.P.), National Cancer Institute, National Institutes of Health, Bethesda, Md; Department of Diagnostic and Interventional Imaging, University of Texas Health Science Center, Houston, Tex (V.S.T.); Departments of Radiology (A.B.R.) and Urologic Oncology (S.S.T.), New York University Langone Health, New York, NY; Department of Radiology, University of Cincinnati Medical Center, Cincinnati, Ohio (S.V.); Department of Urology, University of Minnesota Institute for Prostate and Urologic Cancers, Minneapolis, Minn (C.A.W.); and Department of Radiology, Virginia Commonwealth University, Richmond, Va (J.Y.).