Volume 19, Issue 4 (October 1974)
Pathologic Criteria of Radiation Injury
The many lesions associated with response to radiation are best considered on the base of dose, amount of body irradiated, duration of the radiation exposure, and time since exposure. Ionizing radiation of different types—X-ray, radium, neutrons—produces essentially similar effects, allowing for differences in dose and in linear energy transfer. The symptomatic reaction to overwhelming whole-body doses of radiation—thousands of rads—is almost immediate disorientation or coma with prompt death. There is no distinctive lesion present at death because of insufficient time for its development. In those few who survive some hours, generalized erythema appears. When tissues are examined histologically, there is little obvious change. Necrosis may be present in lymphoid tissues, as well as congestion and phagocytosis of lymphocytes and red blood cells by reticulum cells and macrophages. Mitosis is absent in tissues where normally active, such as germinal centers of lymphoid tissue, hematopoietic tissue in general, crypts of the intestinal glands, and testes.