Abstract
BACKGROUND: The comparative diagnostic performance of biparametric MRI (bpMRI) versus multiparametric MRI (mpMRI) for clinically significant prostate cancer (csPCa) continues to be debated. This study aimed to compare mpMRI and bpMRI in detecting csPCa across prostate-specific antigen (PSA) strata and identify supplementary tools comparable to dynamic contrast-enhanced (DCE) imaging. METHODS: Images were evaluated using mpMRI-based mp-PI-RADS and bpMRI-based bp-PI-RADS and simplified PI-RADS (S-PI-RADS) schemes. The lesion volume (LV) was manually segmented by a radiologist using ITK-SNAP software on high b-value DWI images. The diagnostic performance was assessed via receiver operating characteristic (ROC) curve analysis. The differences of T2WI-score, DCE assessment and LV between csPCa and non-csPCa in peripheral zone (PZ) with DWI category 3 were compared. RESULTS: For overall PSA, mp-PI-RADS and bp-PI-RADS showed comparable AUCs (0.889 vs. 0.882; P > 0.05). When PSA ≤ 10 ng/ml, mp-PI-RADS exhibited the highest specificity (91.0% vs. bp-PI-RADS: 64.4%, S-PI-RADS: 75.0%) and PPV (73.0% vs. bp-PI-RADS: 47.7%, S-PI-RADS: 52.5%). When PSA > 10 ng/ml, S-PI-RADS demonstrated higher sensitivity (91.6% vs. mp-PI-RADS: 83.2%, bp-PI-RADS: 81.2%) and F1-score (0.873 [0.822-0.924] vs. mp-PI-RADS: 0.832 [0.778-0.886], bp-PI-RADS: 0.831 [0.777-0.885]). Among DWI category 3 PZ lesions, neither DCE nor T2WI significantly stratified csPCa risk (P = 0.657 and P = 0.424), whereas LV ≥ 0.5 cm³ showed markedly higher csPCa risk (83.8% vs. 45.8%; P < 0.001). CONCLUSIONS: While mpMRI and bpMRI exhibit comparable overall diagnostic performance but context-dependent strengths: mpMRI demonstrates higher specificity for avoiding unnecessary biopsies when PSA ≤ 10 ng/ml, whereas bpMRI (particularly S-PI-RADS) maximizes sensitivity for csPCa detection when PSA > 10 ng/ml. LV is anticipated to serve as a complementary radiological biomarker at the absence of DCE.