(UroToday.com) Radium 223 (Ra223) is a bone-seeking, alpha-emitting radionuclide that has been shown to improve overall survival and time to skeletal-related events in men with metastatic castrate-resistant prostate cancer (mCRPC)1. In the prospective, phase 3, randomized trial (ERA 223), the combination of Ra 223, abiraterone acetate, and prednisolone was associated with an increased risk of fracture compared with abiraterone acetate, prednisolone, and placebo2.