Abstract

Development of supervoltage treatment machine may minimize skin reaction by skin-sparing effect, but skin damage is still one of “the dose limiting factor” in radiation therapy. In spite of these importance, systemic histopathologic studies of skin in similar conditions which used in clinical treatment has not been performed so far. 60 mice were irradiated with conventional fraction (200x5/wk) and whole abdominal field (2x3 cm, from symphysis pubis to xyphoid process). Used machine was 250 KV, 24 mA. orthovoltage x-ray machine. Histopathological changes of acute skin reaction at the level of total irradiation dose were analyzed and possible mechanism of later chronic changes were investigated. Obtained results are as follows 1. In 1,000 rad irradiated group, only mild epidermal edema is noted. 2. In 2,000 rad irradiated group, slightly decreased number and size of hair follicles and appendages, dermal edema and scanty infiltration of inflammatory cells are visible. 3. In 3,000 rad irradiated group, marked increased capillary congestion and prominent infiltration of inflammatory cells are observed. 4. In 4,000 rad irradiated group, vascular wall thickening with proliferation of endothelial cells are prominent. Dermal thinning and hyalinization are newly developed. 5. In 5,000 rad irradiated group, complete desquamation of epidermis is not seen, despite of acceleration of all above mentioned changes.