An assessment of RBE of Californium-252 for C57-Black/6 mouse fibrosarcoma by a precise afterloading technique.

Afterloading techniques were developed for the in vivo assessment of the RBE of californium-252 with respect of radium-226 using a fibrosarcoma in mice. The afterloading holder positions sources so that the tumor is uniformly irradiated. Using the end points of tumor volumetric studies up to 150 days after irradiation, it was found that the RBE ranged from 5-8 at clinically relevant dose rates and total doses.