CONTRIBUTION OF RADIOBIOLOGY TO CLINICAL- PRACTICE

Advances in radiation therapy are increasingly stemming from insights gained by radiobiological studies. The curriculum for radiation oncolo gists now includes courses on radiobiology. The biological bases of mo dern radiation therapy are reviewed herein. The concepts and experimen tal data that form the rationale for current developments in radiation therapy for cancers are outlined. Fractionation into several daily do ses, accelerated delivery to minimize the effects of tumor repopulatio n, methods for overcoming hypoxia-induced radioresistance, and combine d use of radiation therapy and chemotherapy are currently the best met hods for optimizing the efficacy of radiation. Some of these methods h ave yielded conclusive benefits in clinical studies, whereas others ar e still investigational.