Edema: A Delayed Complication of Total-Body 32-Mev Proton Irradiation

Abstract

In the previous paper an experiment was described in which a large group of primates (Macaca mulatta) were irradiated with spaced single doses of 32-Mev protons (1). The result of this investigation showed that doses between 1440 and 5200 rads of these protons produced severe cutaneous injury. During the initial quiescent period of approximately 2 weeks after exposure, the only significant signs were cutaneous erythema and epilation. The next 2 weeks found the skin changes becoming progressively worse; the erythema led to ulceration, which was soon followed by secondary infection. Because the 32-Mev protons lack sufficient range (1 cm in soft tissue) to reach the more deeply located bone marrow and gastrointestinal tract, radiation damage did not appear in these structures. Consequently, the skin and subcutaneous tissues bear the weight of the radiation injury. At approximately 5 weeks postirradiation, the skin lesions began to heal in those animals that survived the acute effects of doses of 1440 to 1880 rads. For 2 animals, however, the healing was only transitory. The atrophic epithelium that covered the previously ulcerated areas broke down and became reinfected. At the time of this breakdown, both animals developed massive swelling of the head. Somewhat less severe collections of edema occurred in the perineum, in the sheath of the rectus abdominis muscle, and in other superficial areas of the body.