A Radium-223 microgenerator from cyclotron-produced trace Actinium-227

The alpha particle emitter Radium-223 dichloride ( 223 RaCl 2 ) has recently been approved for treatment of late-stage bone metastatic prostate cancer. There is considerable interest in studying this new agent outside of the clinical setting, however the supply of 223 Ra is limited and expensive. We have engineered a 223 Ra microgenerator using traces of 227 Ac previously generated from cyclotron-produced 225 Ac. Radiochemically pure 223 RaCl 2 was made, characterized, evaluated in vivo, and the source was recovered in high yield for regeneration of the microgenerator.