The combination of methyl-CCNU and irradiation: cell survival studies on a human tumor xenograft

Cell survival studies on a human tumor xenograft grown in mice have demonstrated that the chemotherapeutic drug methyl-CCNU can increase the cytotoxic effect of γ-irradiation. Injection of 25 mg/kg of methyl-CCNU three hours before irradiation was the most effective time schedule of those tested. This pre-treatment reduced the D_o of the radiation survival curve from 231 rad to 135 rad without showing any evidence of a reduced shoulder.