Diagnosis and Risk Stratification of PI-RADS v2.1 Category 3–5 Lesions Using Amide Proton Transfer Imaging

Abstract

Objectives: To explore the value of amide proton transfer-weighted imaging (APTWI) combined with apparent diffusion coefficient (ADC) and prostate-specific antigen density (PSAD) in evaluating the risk of aggressive PI-RADS v2.1 category 3–5 lesions. Materials and Methods: We retrospectively analyzed clinical and MRI features of 69 patients with prostate cancer (PCa) and 32 patients with benign prostatic lesion (BL). The PCa group was classified into Gleason Grade Groups (GG) 1 to 4 based on Gleason Score (GS). APTWI parameters, ADC, and PSAD were compared among the different groups. The receiver operating characteristic (ROC) curve was used to assess the diagnostic accuracy of each parameter, and Spearman rank correlation was used to analyze the relationship between APTWI parameters and GS. Results: APTWI parameters, ADC, and PSAD were significantly higher in the PCa group than in the BL group, whereas ADC was significantly lower in the PCa group than in the BL group. ADC showed the highest AUC in the diagnosis of PCa, followed by PSAD and APT_min. Combined analysis showed that APT_min+ADC+PSAD exhibited the highest AUC (0.997). In the PCa group, significant differences in APTWI parameters were found among GG1 to GG4 (P<0.001), with intra-group comparisons showing significant differences between GG1 and GG3, GG1 and GG4, GG2 and GG3, and GG2 and GG4 subgroups. The AUC of APT_mean was greatest in evaluating the risk of aggressive PCa (0.843), which further increased when APT_mean was combined with ADC and PSAD (0.859). Conclusion: In PI-RADS v2.1 category 3–5 lesions, APT can serve as an important biomarker for the risk stratification of PCa, and combining APT with PSAD and ADC achieves the highest diagnostic efficacy.