Prostate Biopsy Strategy Integrating Prostate Health Index and Multiparametric Magnetic Resonance Imaging Optimizes the Predictive Value of Clinically Significant Prostate Cancer in Prostate Imaging Reporting and Data System Gray-Zone Imaging

Purpose: The Prostate Health Index (PHI) and multiparametric magnetic resonance imaging (mpMRI) are used as complementary tools for more accurate diagnosis in men with suspected prostate cancer (PCa). This study investigated whether the combination of PHI and mpMRI better predict clinically significant PCa (csPCa), defined as a Gleason score of ≥7. Materials and Methods: Ninety-four men with clinical suspicion of csPCa were prospectively included. PHI was determined before the prostate biopsy. A uroradiologist reviewed mpMRI findings by using the Prostate Imaging Reporting and Data System version 2.1 (PI-RADS version 2.1). Fusion-targeted biopsy with systematic biopsy was performed in patients with any suspicious lesions on MRI (PI-RADS assessment category ≥3), whereas systematic biopsy was performed in patients without suspicious lesions. The diagnostic values of different biomarkers and PI-RADS were compared by the area under the receiver operating curve (area under the curve [AUC]) for detecting csPCa. Results: Forty-nine (52%) patients were diagnosed with csPCa. The csPCa group had higher median PHI and more abnormal MRI findings than did the non-csPCa group. The median total prostate-specific antigen (PSA) level was similar between the PI-RADS 3 and 4 lesion groups. The median PHI values increased and more patients were diagnosed as having csPCa with an increase in PI-RADS. The receiver operating characteristic curve indicated that PHI and MRI (AUC 0.85 and 0.82, respectively) predicted csPCa more accurately than did the total PSA, free PSA ratio, and PSA density. Adding PHI to mpMRI significantly increased the diagnostic accuracy for csPCa ( P = 0.004). PHI remained the optimal biomarker in patients with “gray zone” PI-RADS 3 or PI-RADS 4 lesions. Conclusion: PHI can guide decision-making for prostate biopsy for patients with gray-zone mpMRI lesions. We proposed a biopsy strategy incorporating PHI and MRI which resulted in the avoidance of biopsies in 35% of the patients.