Effects of radiomodifiers on high and low LET responses in vivo

The radioprotector WR-2721 and the radiosensitizer misonidazole have been studied for their influence on the response of mouse skin and tumours when irradiated with either single or fractionated doses of 240 kV X-rays or 3 MeV neutrons. The modification of radiosensitivity to neutrons was significantly less than that for X-rays, both for tumours and skin. When the two drugs were given in combination before single neutron doses, competitive interaction was observed.