Effects of Field Size on the Survival of Pig Epidermal Colony-forming in Situ after Electron Irradiation

Abstract

The survival of colony-forming cells in pig epidermis after irradiation was measured using different electron field sizes. The sensitivity of the colony-forming cells was characterized by D₀ = 2·5–3·0 Gy. There was an effect of field size, described approximately by: Dose (to give five colonies/cm²) (Gy) = (31 ± 2) × Area^{−(0·048 ± 0·015)}. The effect of field size was less than found previously using tolerance to skin reactions (area exponent = 0·16). This work indicates for the first time that the effects of different large field sizes in skin can be detected at the level of colony-forming cell survival.