Would you treat a patient with metastatic castration resistant prostate cancer and prior treatment with Ra-223 with Lu-117-PSMA-617 therapy?  

Yes, assuming they are otherwise eligible with PSMA + disease, acceptable blood counts, etc. In fact, in cases with patients with bone only disease, many argue to start with Ra223 rather than Lu117 as if they progress beyond bone only disease and are treated with Lu117, they will not be able to...