Eur Radiol. 2026 Aug 13. doi: 10.1007/s00330-026-12792-1. Online ahead of print.
ABSTRACT
OBJECTIVES: To evaluate the prognostic significance of whole-body diffusion-weighted imaging (WBDWI)-derived metrics, including total diffusion volume (TDV) and global apparent diffusion coefficient (gADC), in patients with metastatic castration-resistant prostate cancer (mCRPC).
MATERIALS AND METHODS: This retrospective single-centre study included patients with mCRPC and bone-predominant disease who underwent whole-body MRI (WBMRI) prior to the start of a new treatment. Bone lesions were segmented on b900 DWI using an AI-assisted tool with radiologist refinement, and TDV and gADC were extracted. Automated bone scan index (aBSI) was calculated when bone scintigraphy was available. Clinical and laboratory parameters were recorded. Overall survival (OS) was the primary endpoint. Kaplan-Meier analysis and Cox regression models were used to assess prognostic associations.
RESULTS: Among 360 patients, higher TDV was associated with significantly shorter OS (median OS: 13.2 vs 33.4 months; p < 0.001), whereas gADC showed no significant association. In multivariable analysis including patients with WBMRI and bone scintigraphy (n = 182), log-TDV (HR 1.20; p = 0.027), LDH > 500 U/L (HR 7.79; p < 0.001) and ALP between 200 and 400 U/L (HR 1.78; p = 0.019) were independently associated with OS, while aBSI was not. In patients without aBSI data (n = 85), log-TDV remained prognostic (HR 1.60; p < 0.001), whereas LDH and ALP were not.
CONCLUSION: TDV derived from WBDWI independently predicts OS in mCRPC and demonstrates stronger prognostic performance than aBSI and conventional laboratory markers in multivariable models, whereas gADC was not prognostic.
KEY POINTS: QuestionThere is no widely adopted quantitative imaging biomarker for prognostic stratification in mCRPC. Can whole-body diffusion-weighted MRI-derived metrics improve prognostic risk stratification in patients with bone metastases? FindingsHigher TDV of bone disease on baseline whole-body diffusion-weighted MRI was independently associated with shorter OS in patients with mCRPC. Clinical relevance Whole-body diffusion-weighted MRI-derived tumour volume may provide a practical quantitative imaging biomarker for prognostic stratification in mCRPC, potentially supporting individualised treatment planning.
PMID:42593500 | DOI:10.1007/s00330-026-12792-1
