The introduction and development of radium and x-rays as therapeutic agents in cancer has raised pertinent questions concerning the radiosensitivity of normal and neoplastic cells, which have assumed both a theoretical interest and practical importance. These problems concern the pathologist, surgeon and radiologist alike, for each is called on to render important decisions on the treatment of cancer, which involve an intimate knowledge of the established principles of radiosensitivity.
It is my purpose in this communication to present a critical summary of some of the biologic, pathologic and clinical knowledge of radiosensitivity so far as it applies to the practical problems of the treatment of cancer.
An immense literature has accumulated on this subject and much of the evidence presented is both confusing and conflicting. Some of the reasons for the state of confusion are at once obvious. Perhaps the most important is the fact that the science of radiation