At what point would Radium-223 dicholoride treatment be the best management for a patient with established metastatic prostate cancer with an elevated PSA and symptomatic bone pain with corresponding bone lesions on imaging?

At present, based on the randomised trial, it is approved for castrate resistant prostate cancer (can be chemo naive) with symptomatic bone only disease. In that situation, it improves all skeletal related events and survival and should be an indication to talk about this treatment. However, in practice we are seeing patients who are not only castrate resistant, but also hormone refractory (having been treated with with enzalutamide and abiraterone acetate, which were not available when the Xofi...