The cellular basis of radiotherapeutic response

After surgery, radiotherapy is the most important modality in current use for the care and management of human cancer. Radiation is understood to effect cancer cures by destroying the proliferative capacity of tumor cells and is effective in controlling local disease. Recent evidences suggest that the intrinsic radiosensitivities of cells derived from various cancers may indeed correlate with the amount of radiation dose required to control those cancers. Several physical, chemical, biological and physiological factors which influence cellular radiation response have been well characterized and are important in understanding the radio-responsiveness of individual tumors. As a science, cellular radiation biology has developed to the stage where it can reasonably explain current treatment protocols which had been empirically defined over 70 yrs. Radiobiologists are now equipped with several sophisticated techniques which might be exploited to refine such protocols and define new ones. There are several reasons to expect that new radiobiological techniques and rationales for improved cancer treatment will eventually result in improved local control and additional cures of this disease. (author)