Metastatic Diffusion Volume Based on Apparent Diffusion Coefficient as a Prognostic Factor in Castration-Resistant...

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Whole-body diffusion-weighted MRI (WB-DWI) aids in assessing castration-resistant prostate cancer (CRPC) disease activity.
• The MET-RADS-P system standardizes WB-DWI interpretation but lacks quantitative evaluation.
• Quantitative analysis of WB-DWI for CRPC has not been extensively explored.

Purpose of the Study:

• To assess the validity and prognostic significance of quantitative WB-DWI using apparent diffusion coefficient (ADC) values in CRPC.
• To explore quantitative imaging biomarkers for CRPC prognosis.

Main Methods:

• Retrospective study of 66 CRPC patients (median age 75 years).
• 1.5 T WB-DWI with b-values of 0 and 1000 s/mm² was performed.
• Apparent diffusion coefficient (ADC) values were used to calculate metastatic tumor diffusion volume (mDV) and metastatic lesion ADC (mADC).

Main Results:

• Metastatic diffusion volumes (mDVs) strongly correlated with MET-RADS-P scores (r=0.90/0.87, P<0.05).
• mDV demonstrated a significant association with cancer-specific survival (CSS) (HR: 1.01, P<0.05).
• mDV calculated using ADC values (mDV₀.₄₋₀.₉) and prior therapeutic lines were independent predictors of CSS shortening (HR: 1.02 and 1.35, P<0.05).

Conclusions:

• Quantitative assessment of metastatic tumor volume via ADC values is valuable for CRPC prognosis.
• WB-DWI holds potential as a prognostic imaging biomarker for CRPC.