The action of radium on cancer cells. II.—Some factors determining the susceptibility of cancer cells to radium

The susceptibility to radium of different types of cells and tissues is one of the outstanding problems of radiotherapy, both from the theoretical and practical points of view. In the organism, normal and malignant tissues exhibit great variations in their response to short-wave radiation. Some normal tissues, e. g., lymph glands and tests, are extremely sensitive, while others are much less so. There are similar variations in sensitivity between different malignant new growths when irradiated in the organism. There is, however, more uniformity in the effects of irradiation on normal and malignant tissues when isolated cell-masses are studied. Similar biological and morphological changes are observed after irradiation of tissues cultures, whether of normal fibroblasts or tumour cells; and the metabolic disturbances induced in slice of tumour tissue, tests and spleen are of the same type and magnitude (Crabtree, 1932).