Radium-223 Utilization Patterns and Outcomes in Clinical Practice

Radium-223 was approved for metastatic castration-resistant prostate cancer based on the ALSYMPCA trial. We characterize radium-223 treatment patterns and overall survival (OS) in a large equal access health system.

We identified all men within the Veterans Affairs (VA) Healthcare System who received radium-223 between January 2013 and September 2017. Patients were followed until death or last followup. We abstracted all treatments received prior to radium; no treatments after radium were abstracted. Our primary aim was understanding practice patterns, and secondary outcome was the association between treatment pattern and OS measured using Cox models.

We identified 318 bone metastatic castration-resistant prostate cancer patients who received radium-223 within the VA Healthcare System. Of these patients 277 (87%) died during followup. The 5 predominant treatment patterns that encompassed 88% of patients (279/318) were 1) androgen receptor-targeted agent (ARTA)-radium, 2) docetaxel-ARTA-radium, 3) ARTA-docetaxel-radium, 4) docetaxel-ARTA-cabazitaxel-radium and 5) radium alone. Median OS was 11 months (95% CI 9.7-12.5). Men who received ARTA-docetaxel-radium had the worst survival. All other treatments had similar outcomes. Only 42% of patients completed the full 6 injections; 25% received only 1 or 2 injections.

We identified the most common radium-223 treatment patterns and their association with OS within the VA population. The better survival in ALSYMPCA (14.9 months) vs our study (11 months) along with 58% of patients not receiving the full radium-223 course suggests radium is being used later in the disease course in the real world in a more heterogeneous population.