Prospective Inclusion of Apparent Diffusion Coefficients in Multiparametric Prostate MRI Structured Reports: Discrimination of Clinically Insignificant and Significant Cancers

OBJECTIVE. The purpose of this study was to assess the diagnostic performance of prospectively assigned mean apparent diffusion coefficient (ADC) values in multiparametric MRI (mpMRI) structured reports for discriminating clinically insignificant (International Society of Urological Pathology [ISUP] group 1) from clinically significant (ISUP groups 2–5) prostate cancer. MATERIALS AND METHODS. This single-center study included men with abnormal 3-T mpMRI findings (Prostate Imaging Reporting and Data System version 2 score, ≥ 3) who subsequently underwent radical prostatectomy or targeted biopsy with positive results. One of nine radiologists prospectively reported the mean ADC for each lesion during clinical interpretation. Lesions with ADC ≤ 0.700 mm2/s × 10–3 were flagged as concerning for clinically significant prostate cancer. The index lesion at MRI correlated with the site-concordant lesion at targeted biopsy or whole-mount histopathologic analysis. Logistic regression was used to evaluate the utilit...