Abstract
Effects of the hypoxic cell radiosensitizer (RP-170) in fractionated radiotherapy on therapeutic benefit were studied using Lewis lung carcinoma. A single dose of irradiation with RP-170 prolonged the tumor growth time depending on the dose of RP-170 and irradiation. Although, there was no significant difference, high doses of RP-170 also seemed to slightly enhance the skin reaction to irradiation in ICR and BDF1 mice. Fractionated irradiation combined with RP-170 significantly prolonged the tumor growth time depending on total dosage and each fractionated dose of RP-170. Sixteen administrations of low doses of RP170 (80mg/kg) with 3Gy of radiation achieved a therapeutic gain of 1.1. Survival time of mice was prolonged and was related to the growth prolongation. The radiosensitizer, RP-170, may be valuable in fractionated radiation therapy.
