Treatment of radiation-induced normal tissue lesions

ormal tissue damage is the most important limiting factor in radiotherapy. It must be possible, at least theoretically, to eradicate a localised tumour if a large enough dose of radiation could be delivered to tumour, however, practically, there is always the danger of damaging normal tissues adjacent to the tumour. Factors such as the total radiation dose, overall treatment time, dose per fraction, dose-rate and the effects of changing the irradiated volume of the spinal cord have been examined in order to improve the therapeutic ratio in radiotherapy. The majority of these studies have concentrated on optimizing dose fractionation schedules. Only recently have attempts been made to modify this effect by the administration of therapeutic agents after irradiation but before the development of the lesion. Despite this interest the problem still exists. At present there is no effective clinically applied treatment towards radiation-induced normal tissue injury, however, some symptoms for example swelling or pain during inflammatory phase may respond to corticosteroids (Godwin-Austen 1975). There are a number of agents, which have been used experimentally, some clinically, to alleviate radiation damage. The results of these studies are reviewed here.