Fig. 6
MR images in a 63-year-old man with a prostate-specific antigen (PSA) level of 7.39 ng/ml. The prostate volume measured by MRI was 42.42 ml, and the PSA density was 0.174 ng/ml2. Multiparametric MRI demonstrated a lesion measuring 1.1 cm in the left posterior peripheral zone midgland (arrow) and ill-defined margins on T2-weighted images with severe restricted diffusion and early contrast enhancement; Prostate Imaging Reporting and Data System (PI-RADS) category 4. On subsequent cognitive MRI-target biopsy, all 3 targeted cores demonstrated Gleason score (GS) 4 + 5 with maximum tumor core involvement of 57%. Five out of 12 systematic biopsy (SB) cores were positive for prostate cancer with the highest GS 4 + 5 and maximum tumor core involvement of 26%. At a risk threshold of 60%, both the MRI model (predicted risk: 67.6%) and the combined model (predicted risk: 65.6%) would have resulted in obviating SB. The predicted risk for the clinical model was 35.7%. The patient would have undergone unnecessary SB based on the clinical model and PI-RADS 5 strategy. ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging; DCE, dynamic contrast-enhanced; T2w, T2-weighted imaging