Assessing Therapeutic Response to Radium-223 with an Automated Bone Scan Index among Metastatic Castration-Resistant...

Area of Science:

• Nuclear Medicine
• Oncology
• Radiopharmaceuticals

Background:

• Metastatic castration-resistant prostate cancer (mCRPC) poses significant treatment challenges.
• Radium-223 (Ra-223) is a targeted alpha therapy used for mCRPC with bone metastases.
• Accurate assessment of treatment response and survival prediction is crucial for managing mCRPC patients.

Purpose of the Study:

• To evaluate the automated bone scan index (aBSI) as an imaging biomarker for treatment response.
• To assess the utility of aBSI change in predicting overall survival (OS) in mCRPC patients treated with Ra-223.
• To correlate aBSI changes with established serum markers like alkaline phosphatase (ALP) and prostate-specific antigen (PSA).

Main Methods:

• Retrospective analysis of 205 mCRPC patients treated with Ra-223.
• Bone scintigraphy performed before and after Ra-223 treatment to calculate aBSI.
• Statistical analysis including Cox proportional-hazards model and Kaplan-Meier curves to assess OS.
• Correlation analysis between changes in aBSI, ALP, and PSA levels.

Main Results:

• A decline in aBSI was observed in 52.7% of patients post-treatment.
• Changes in PSA, aBSI, and ALP were all identified as significant prognostic factors for OS.
• aBSI change demonstrated a hazard ratio of 2.22 (95% CI 1.43-3.59, p=0.0003) for OS.

Conclusions:

• aBSI change is a valuable imaging biomarker for assessing treatment response in mCRPC patients undergoing Ra-223 therapy.
• aBSI serves as a significant predictor of overall survival in this patient population.
• Integrating aBSI assessment with serum markers can enhance treatment monitoring and prognostic accuracy.