Abstract
BACKGROUND AND PURPOSE: The non-invasive differentiation of prostate cancer (PCa) from benign prostatic hyperplasia (BPH) and the accurate assessment of tumor aggressiveness remain critical clinical challenges. This study aimed to evaluate the diagnostic performance of amide proton transfer-weighted (APTw) MRI and, specifically, to determine its incremental value over the standard Prostate Imaging-Reporting and Data System (PI-RADS v2.1) and serum PSA. METHODS: In this retrospective study, 160 patients (86 PCa, 74 BPH) underwent 3.0T multi-parametric MRI, including APTw imaging. Quantitative APTw values were compared with Apparent Diffusion Coefficient (ADC) values and PI-RADS v2.1 scores. Receiver operating characteristic (ROC) analysis was employed to evaluate the diagnostic performance of individual parameters and combined models. Subgroup analyses were performed for lesions in the Transition Zone (TZ) and patients in the PSA "gray zone" (4-10 ng/mL). Additionally, the correlation between APTw values and the Gleason Score (GS) was assessed. RESULTS: APTw values were significantly higher in the PCa group compared to the BPH group (2.1% ± 0.5% vs. 1.3% ± 0.6%, p < 0.001). While PI-RADS v2.1 alone showed high diagnostic efficacy (AUC = 0.875), the combined model (APTw + PI-RADS v2.1) achieved the highest accuracy with an AUC of 0.915, significantly outperforming PI-RADS alone (p < 0.05). In the challenging PSA "gray zone", APTw imaging maintained robust diagnostic performance (AUC = 0.80), significantly outperforming serum PSA (AUC = 0.75). Furthermore, a significant positive correlation was observed between APTw values and GS (Spearman's ρ = 0.407, p < 0.001), and APTw successfully differentiated high-risk (GS ≥ 8) from low- and intermediate-risk PCa (AUC = 0.715). CONCLUSION: APTw imaging correlates with tumor aggressiveness and provides excellent diagnostic performance for differentiating PCa from BPH. Crucially, it offers incremental diagnostic value to the standard PI-RADS v2.1 assessment and demonstrates robust utility in challenging clinical scenarios, such as the PSA gray zone, thereby serving as a valuable non-invasive biomarker for risk stratification.