A staple delivery applicator for delivering radioactive staples during brachytherapy medical treatment has an actuating device for attaching source staples located distally thereform. The actuating device is removably attachable to an actuator arm on a proximal end. A staple applicator cartridge holder is attached to the actuator arm on a distal end. The staple applicator cartridge is mountable in the holder and has slots for mounting of radioactive source staples therein. An anvil therein crimps the staples. The staple applicator cartridge holder is removably mountable in a connector and the connector is also removably mounted to a surgical staple holder. A trigger device has a control for closing the anvil of the cartridge holder and for firing of the source staples in the cartridge therein to cause the staples to crimp, and a control for opening the anvil and releasing the trigger device from the actuator arm.