Radioprotective agents in medicine.

The diminished probability of strategic nuclear confrontation alleviates some of the global concerns about large numbers of radiation casualties in the event of a nuclear war. As a result of the protection of the environment, the management of smaller numbers of radiation casualties assumes a more predictable and more specific role confined to accidents in nuclear energy projects, industry, technology and science. Recent experience of the consequences of accidents in nuclear power plants, in the field of radiotherapy and in the disposal of radioactive waste and spent fuel, present the medical and scientific communities with formidable problems if such events are to lead to minimal adverse effects on the biosphere. Whereas it is not possible to predict a nuclear or radiation accident, radioprotection is hardly an issue of health science alone, but rather an issue of the strictest quality assurance in all aspects of the utilization of nuclear energy and ionizing radiation. Thus, the medical community concerned with radioprotection will have to confine its emphasis on the management of radiation-induced alterations of the human organism from acute radiation syndromes to the stochastic concepts of chronic alterations of radiosensitive organic systems. Current multidisciplinary research in the field of radioprotection involves all aspects of basic and clinical research ranging from the subatomic mechanisms of free radical formation, macromolecular and intracellular radiation-induced alterations, biochemical and physiological homeostatic mechanisms and organ level manifestations to the clinical management of radiation casualties in a controlled hospital environment. Radioprotective agents, although widely studied in the past four decades and including several thousand agents, have not reached the level of providing the field of medicine with an agent that conforms to all criteria of an optimal radioprotectant, including effectiveness, toxicity, availability, specificity and tolerance. This article discusses the current state of radioprotection in medical therapy, and emphasizes a need for continued research in the area of medical management of radiation casualties from the viewpoint of a realistic probability of nuclear incidents or accidents in the nuclear energy-dependent world at the end of the millennium.