Prospective Evaluation of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for Prostate Cancer Detection.

and Objective: PI-RADSv2 was developed to standardize interpretation and reporting of multiparametric prostate MRI (mpMRI) and provide guidelines for biopsy of mpMRI findings. We prospectively evaluated the cancer detection rate (CDR) at each overall PI-RADSv2 score.

This prospective study included 62 consecutive patients with 116 lesions who underwent multi-parametric prostate MRI at 3T with PI-RADSv2 evaluation and subsequent targeted MRI/TRUS fusion-guided biopsy (FgBx) and concurrent 12-core systematic prostate biopsy (SBx) between May-September 2015. Median patient age and PSA values were 65.5 years (range: 50.3-76.6) and 7.10 ng/mL (range: 0.47-863.0), respectively. Mean lesion size was 12.7mm overall. Lesion-based CDRs for all tumors and Gleason ≥3+4 tumors at each PI-RADSv2 score were calculated. Univariate analysis was performed to assess differences in CDR between PI-RADSv2 scores.

116 lesions in 62 patients were evaluated prospectively (0 PI-RADS 1, 18 PI-RADS 2, 19 PI-RADS 3, 47 PI-RADS 4, 32 PI-RADS 5) and underwent FgBx and SBx. Histopathology revealed 55/116 (47.4%) cancers (17 Gleason 3+3, 16 Gleason 3+4, 6 Gleason 4+3, 12 Gleason 4+4, 3 Gleason 4+5, 1 Gleason 5+4). Based on targeted biopsy (Tbx) on a per lesion basis, the overall CDRs of PI-RADS 2, 3, 4 and 5 score for all tumors was 22.2%, 15.8%, 29.8% and 78.1% respectively. The CDR of PI-RADS 2, 3, 4, and 5 score for Gleason ≥3+4 tumors was 5.6%, 0%, 21.3%, and 75%, respectively. Differences in the CDR between overall PI-RADS 4 and 5 scores were significant (p<0.001 for both Gleason >3+3 and Gleason ≥3+4 cancers).

PI-RADS score of 5 had the highest prospective CDR (78%). PI-RADS score of 4 had only a 30% CDR which is lower than expected. Surprisingly, no or very few significant cancers were detected at a PI-RADS score of 3 (16%). This early prospective data suggests that current criteria results in a high false positive rate that lowers the CDR. Therefore, stricter criteria may be needed in the future to decrease false positives and increase the CDR for PI-RADS scores of 3, 4 and 5.

The Journal of urology. 2016 Apr 18 [Epub ahead of print]

Francesca V Mertan, Matthew D Greer, Joanna H Shih, Arvin K George, Michael Kongnyuy, Akhil Muthigi, Maria J Merino, Bradford J Wood, Peter A Pinto, Peter L Choyke, Baris Turkbey

Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA., Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA., Division of Cancer treatment and Diagnosis: Biometric Research Program, NCI, NIH, Rockville, MD, USA., Urologic Oncology Branch, NCI, NIH, Bethesda, MD, USA., Urologic Oncology Branch, NCI, NIH, Bethesda, MD, USA., Urologic Oncology Branch, NCI, NIH, Bethesda, MD, USA., Laboratory of Pathology, NCI, NIH, Bethesda, MD, USA., Center for Interventional Oncology, NCI and Radiology and Imaging Sciences, Clinical Center, NIH, Bethesda, MD, USA., Urologic Oncology Branch, NCI, NIH, Bethesda, MD, USA., Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA., Molecular Imaging Program, NCI, NIH, Bethesda, MD, USA. Electronic address: .