The Dose-survival Relationship for Irradiation of Epithelial Cells of Mouse Skin

Abstract

That skin will regenerate from a single epithelial cell surviving irradiation is probable. This provides a method for estimating the numbers of these cells surviving a dose of radiation. A technique is described whereby a dose-survival relationship for skin epithelial cells was established using 29 kVp X rays. Between doses of 900 and 2,300 rads the relationship may be described by a survival curve having a value for D0 of 135 rads. The effect of a dose of radiation on skin is expressed as the number of cells surviving per unit area and not as the usual surviving fraction because it is not possible to count accurately the numbers of clonogenic epithelial cells per square centimetre of unirradiated skin. For this reason also, the origin of the survival curve and the related extrapolation number cannot be determined. Gross responses of skin are discussed in the light of epithelial cell survival characteristics. It is unlikely that mouse skin will ulcerate if more than 10–20 cells per square centimetre survive irradiation. It is also unlikely that there are any anoxic cells in the epithelium of skin or hair follicles of anaesthetised air-breathing mice.