 Radium-223 is indicated for the treatment of patients with mCRPC with symptomatic bone metastases and no known visceral metastatic disease. However, very few data have been reported in patients with mCRPC who are asymptomatic or mildly symptomatic. Recently, results from an International Expanded Access Program have also suggested a benefit of radium-223 in asymptomatic patients with mCRPC. In addition, the mechanism of action of radium-223 should not be correlated with the presenceabsence of the AR-V7 mutation, although this issue has not yet been evaluated. 