Treatment with misonidazole and high voltage irradiation of xenotransplanted human carcinomas in nu/nu mice with thymic aplasia

An investigation was conducted in order to determine the effect of combined high voltage irradiation and the sensitizing drug misonidazole (Ro-07-0582) on human gynecologic carcinoma transplanted into nu/nu mice with thymic aplasia. Two carcinomas of the endometrium, two carcinomas of the ovaries, and one carcinoma of the cervix were submitted to Co-60 irradiation with and without misonidazole. The tumor growth was compared to that of control groups. The dosage and fraction of the high voltage irradiation (2 x 5 Gy/week, total dose 60 Gy) were adapted to clinical data. Misonidazole (1 mg/kg body weight) was administered by intraperitoneal injection 15 minutes before the irradiation. Compared with the control animals, the locally irradiated tumors showed a slower growth or even a regression. The administration of misonidazole, however, did not produce significant differences in our five cases. Some reasons for this absence of the radiosensitizing effect of misonidazole are briefly discussed. (orig.)