Prebiopsy multiparametric MRI and PI-RADS version 2.0 for differentiating histologically benign prostate disease from prostate cancer in biopsies: A retrospective single-center comparison

Purpose: To investigate the diagnostic performance of Prostate Imaging-Reporting and Data System version 2.0 (PI-RADSv2.0) for differentiating clinically significant prostate cancer (csPCa) from benign prostate disease on prebiopsy multiparametric MRI stratified by total prostate specific antigen (PSA) concentration.

Materials and methods: 150 patients who had prebiopsy mpMRI, serum PSA concentration and subsequent biopsy were retrospectively analyzed. Patients were stratified by PSA concentration (Group1 ≥ 10 ng/mL; Group2 4.0-<10 ng/mL). MRI findings were assessed using PI-RADSv2.0 by two blinded radiologists. Lesions were graded histopathologically using the International Society of Urological Pathology (ISUP) score. Diagnostic performance of PI-RADSv2.0 was evaluated and compared to PSA and PSA Density (PSAD). The performance of the radiologists was compared including inter-observer agreement for PI-RADSv2.0. The correlation between imaging and histopathological biopsy results was analyzed.

Results: The differences in total PSA, free/total PSA ratio and PSAD between benign (n = 78) and malignant (n = 72) groups were significant (p < 0.05). The PI-RADSv2.0 scores of the radiologists were strongly correlated (r = 0.912, p < 0.001) with excellent agreement, κ = 0.97 (95%CI: 0.90-1.03; p < 0.005). Receiver operating characteristics curve analysis showed significantly high predictive power for PI-RADSv2.0, total PSA and PSAD alone. Comparison of age, prostate volume, PSAD, free/total PSA ratio and total PSA values between ISUP1 and ISUP ≥ 2 cases revealed significantly increased PSAD (p < 0.001) and total PSA (p = 0.001) in the ISUP ≥ 2 group.

Conclusion: PI-RADSv2.0 had high diagnostic accuracy in both PSA groups. PI-RADSv2.0, PSAD and total PSA alone had significant high predictive power to detect csPCa. However, the combination of PI-RADSv2.0 and PSAD or total PSA for each reader showed no statistically significant improvement when compared to PI-RADSv2.0 alone.