Diffusion-weighted MRI in early assessment of tumour response to radiotherapy in high-risk prostate cancer

Objective:The objective of this study was to assess the efficacy of diffusion-weighted MRI (DWI) in monitoring response to radiotherapy in high-risk prostate cancer (PC).Methods:This retrospective study included 78 patients with high-risk PC undergoing 3.0-T MRI (supplemented by DWI) before and after intensity-modulated radiotherapy (IMRT). Based on follow-up clinical examinations, patients were divided into two groups: the recurrence group (patients who suffered biochemical/clinical recurrence within 3 years, n = 13) and the non-recurrence group (patients who were recurrence free for over 3 years, n = 65). The apparent diffusion coefficient (ADC) values before and after IMRT were compared between these two groups. The receiver-operating characteristics (ROC) analysis was carried out to investigate the discriminatory capability for pre- and post-IMRT ADC values.Results:The overall ADC values were 1.04 ± 0.18 × 10−3 mm2 s−1 for PCs before IMRT and 1.45 ± 0.15 × 10−3 mm2 s−1 after IMRT (p < 0.001). A statis...