Clinical radiobiology of low dose-rate radiotherapy

Investigative irradiations of human skin have shown that the total dose required to obtain a dry desquamation does not increase with the duration of the irradiation as rapidly as it would be expected from the kinetics of repair of the sublethal injuries. This suggests that an additional mechanism, probably accumulation of the cells in a sensitive phase, occurs during a continuous irradiation with dose-rate higher than 150 rads/hour. This effect seems to vanish at smaller dose-rates.