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 io ns (plateau region) at the Gesellschaft fur Schwerionenforschung (GSI, Darmstadt, Germany) was compared with changes after 200 kV x-irradiat ion. Carbon doses isoeffective to the x-ray doses were computed with a recently established model for calculation of the biological effect o f heavy ions. Clinical changes and physiological symptoms (blood flow, erythema, trans-epidermal water loss, skin hydration) were scored. Th e parameters analyzed were maximum and mean values of each symptom dur ing 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 concentrati on (p < 0.02) no significant differences could be found in the respons e 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-i ons (plateau region) and may at least for epidermis be applied to trea tment planning.