Prebiopsy Multiparametric MRI With Cancer-Negative Findings in Men With Suspected Prostate Cancer: Evaluation Using Prostate Imaging Reporting and Data System Version 2

OBJECTIVE. The purpose of this study is to investigate the rates and characteristics of missed cancers at prebiopsy multiparametric MRI with cancer-negative findings according to the Prostate Imaging Reporting and Data System (PI-RADS) version 2 in men with suspected prostate cancer (PCa). MATERIALS AND METHODS. A total of 584 consecutive men (biopsy naive, n = 392; repeated biopsy, n = 192) with suspected PCa who underwent prebiopsy 3-T multiparametric MRI, followed by subsequent biopsies, were enrolled. Cancer-positive findings were confirmed at systemic biopsies and cognitive MRI-targeted biopsies, whereas cancer-negative findings were confirmed at systemic biopsies performed during subsequent follow-up. Missing and detection rates of all PCa and clinically significant cancer according to five biopsy-based definitions were determined. The likelihood of PCa at multiparametric MRI was evaluated according to PI-RADS version 2, and the results were compared. RESULTS. Pathologically confirmed cancers were found in 25% of patients. Cancer-positive MRI findings were seen in 99 men (17%) and, of these, 85.9% had PCa. Of 485 men with cancer-negative MRI findings, a total of 61 (12.6%) had PCa, including 46 men in the biopsynaive group and 15 men in the repeated-biopsy group. For clinically significant cancers, the rate of missed cancers at MRI was 0.1-6.0%, and the detection rate was 21.2-83.5%. For detecting PCa, multiparametric MRI had 96.8% specificity, 87.2% accuracy, and 87.4% negative predictive value. CONCLUSION. Prebiopsy 3-T multiparametric MRI with cancer-negative findings missed approximately 12.6% of cases of PCa, including 0.1-6.0% of clinically significant cancers in a cohort of biopsy-naive men and those who had undergone repeated biopsy.