Prognostic value of whole-body diffusion-weighted imaging with background body signal suppression in CRPC patients undergoing Ra-223 therapy: an exploratory analysis.

OBJECTIVES

The aim of this study was to evaluate the utility of diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) in monitoring the response to Ra-223 therapy in patients with castration-resistant prostate cancer (CRPC) and bone metastasis.

MATERIALS AND

METHODS

This retrospective study included 15 patients with CRPC and bone metastases. DWIBS scans were performed at baseline and after three cycles of Ra-223 therapy. Quantitative analysis of tumor total diffusion volume (tDV) categorized patients as stable disease (DWIBS-SD), partial response (DWIBS-PR), or progressive disease (DWIBS-PD). Kaplan-Meier analysis and log-rank tests were used to assess the correlation between DWIBS findings and survival.

RESULTS

Of the 15 patients (median age 72 years ± 7.3), 7 (47%) were classified as DWIBS-SD, 3 (20%) as DWIBS-PR, and 5 (33%) as DWIBS-PD. DWIBS-PD group had significantly shorter survival than the DWIBS-non-PD group (P = 0.004). Despite no significant differences in age, alkaline phosphatase, prostate-specific antigen or bone metastasis volume, DWIBS-PD group had a significantly higher proportion of patients with Eastern Cooperative Oncology Group performance status score of 2 before the treatment compared to DWIBS-non-PD group (P = 0.039).

CONCLUSION

DWIBS is a valuable tool for monitoring treatment response and predicting outcome in patients with CRPC undergoing Ra-223 therapy. Early intervention or treatment modification is recommended for patients with DWIBS-PD.