Role of radiation therapy in the management of neoplasms of the central nervous system.

Radiation therapy plays an important role as an adjunctive treatment modality with surgery and/or chemotherapy in a number of primary and secondary CNS neoplasms, including glioblastoma multiforme, lower grade gliomas, brainstem tumors, medulloblastoma, ependymoma, most pituitary and parapituitary tumors, brain metastases, and epidural spinal cord metastases; it also has an important function in the total management of childhood leukemia. Radiation therapy can also be extremely effective as the primary or sole treatment of pituitary adenomas, craniopharyngioma, and cerebral and epidural metastases. The relative roles of, and indications for, surgery versus irradiation have been discussed. There is clearly a need for more information regarding the natural history relative response of specific tumors to the various therapeutic modalities available, as well as the most effective and safe ways to combine treatments. To this end, it is mandatory that surgeons, radiotherapists, neurologists, pathologists, and internists begin to intercommunicate more freely and objectively. Hopefully, in areas that continue to be controversial, well-designed clinical trials can begin to furnish the necessary answers. This is particularly relevant as all of the disciplines mentioned are developing newer and hopefully more effective diagnostic and therapeutic capabilities.