The long-term effects of cranial irradiation on the central nervous system.

Cranial irradiation and chemotherapy may have significant long-term deleterious effects on children with brain tumors. Intellectual deterioration, endocrinopathies, leukoencephalopathy, extraneural metastases, and oncogenesis may all complicate the treatment of central nervous system neoplasia. These long-term effects of therapy have important implications, as some are amenable to treatment and others may be prevented by the careful monitoring of drug and radiation administration. Until recently, the survivals of children with brain tumors were limited, so that concerns over long-term effects of therapy were unnecessary. As children with certain types of brain tumors now have a better prognosis, these long-term and possibly remediable effects have important implications. This article emphasizes radiation effects on intellect, endocrine function, and oncogenesis. Recommendations for baseline and longitudinal evaluations of children with brain tumors are suggested.