[Radiobiological consideration for standardization and optimization in radiotherapy on cancers].

It is so important for standardization and optimization in radiotherapy on cancers to estimate accurately target volume for irradiation and radiation injury on normal tissues. It is responsible for radiation diagnosticians to determine target volume, but in order to estimate late injuries on normal tissues radiobiological research is seemed to be useful. Concerning normal tissue damage, it is very difficult to forecast late damages on various sort of normal tissues from the standpoint of radiobiology in course of radiotherapy. To dissolve this problem it is needed to develop new biological model systems and to find new marker to forecast late injuries from acute damages. In this paper it is also discussed for establishment of radiation oncology in Japan.