Acute response of pig skin to irradiation with C-12-ions or 200 kV x-rays

The acute response of pig skin to treatment with high energy carbon ions (plateau region) at the Gesellschaft fur Schwerionenforschung (GSI, Darmstadt, Germany) was compared with changes after 200 kV x-irradiation. Carbon doses isoeffective to the x-ray doses were computed with a recently established model for calculation of the biological effect of heavy ions. Clinical changes and physiological symptoms (blood flow, erythema, trans-epidermal water loss, skin hydration) were scored. The parameters analyzed were maximum and mean values of each symptom during days 24 to 70 after irradiation, and the quantal endpoints for the establishment of dose-effect curves were the median values of these. With exception of the maximum change in the red blood cell concentration (p < 0.02) no significant differences could be found in the response to x-rays and RBE-corrected heavy ions. These results indicate that the model is valid for the calculation of biological effects of C-12-ions (plateau region) and may at least for epidermis be applied to treatment planning.