Late sequelae of radiation therapy in cancer of the head and neck with particular reference to the nasopharynx.

Sequlae of radiation therapy may be late in occurring and varied in their manifestations. Although some are untreatable and progressive, the risk of development of some other sequelae can be minimized by careful application of radiotherapy or by ancillary measures, such as dental decay prophylaxis. Some of the serious sequelae secondary to radiation therapy of the nasopharynx have been summarized. These include radiation myelitis, paralysis of the cranial nerves, stricture of the pharynx, radiation-induced cancer, and necrosis with fatal hemorrhage.