Dose-survival characteristics of mouse jejunal crypt cells

Abstract The survival of mouse jejunal crypt cells after multiple doses of 60 Co γ-rays has been measured with the microcolony technique. Fractionation protocols were designed with common dose fractions in regimens with different fraction numbers. An average number of 152 clonogens per crypt was estimated from the experiments. The survival curve has a broad shoulder, remaining near-exponential over the initial dose range 0 to 300 rad, with initial slope 1 D 0 = 357 rad. It is not possible to distinguish between the linear-quadratic (LQ) and two-component (TC) survival models on the basis of the results of these experiments.