(UroToday.com) In the on-demand poster session of the European Society for Medical Oncology (ESMO) Annual Congress, Dr. Elena Castro presented results from the PRORADIUM cohort (NCT02925702) examining the effect of germline mutations on outcomes for patients treated with radium-223. Approved based on data from ALSYMPCA, radium-223 is an alpha-emitter that induces double-strand DNA breaks (DSBs) and selectively targets bone metastases. Such DSBs are accurately repaired by the homologous recombination (HR) pathway that is impaired in a significant proportion of mCRPC patients that harbor pathogenic mutations in HR genes (gHR+). Th authors hypothesized that patients with germline mutations in HR genes may have a potentiated response to radium-223.