[Clinical radiation biology].

Clinical radiobiology covers three fields. 1. Radiation hazards and radiation protection: The fundamentals for evaluation of radiation hazards in man are reviewed. The biomedical effect of low doses is of chief importance in regard to use of radiation in radiodiagnosis and medicine, which account for most artificial radiation exposure in man. Interesting features are stochastic effects without a threshold dose, such as induction of cancer, mutation and developmental anomalies. 2. Optimization of radiotherapy: Apart from amelioration of temporal radiation distribution, possible modifiers are tested such as chemical substances (as sensitizers of tumor cells and protectors of healthy tissue) or hyperthermia. For selective irradiation of the tumor, various kinds of radiation are evaluated, e.g. pions, protons and heavy ions. 3. Public education and information.