Brain tumors in children. II. Advances in neurosurgery and radiation oncology.

In this article, the contributions of neurosurgery and radiation oncology to the management of childhood brain tumors are described. Progress in a particular discipline rarely occurs in an isolated fashion, and it is clear that neurosurgical advances owe much to similar advances in anesthesiology, neuroradiology, and intensive care management. These advances in various disciplines have all permitted bolder yet safer attempts at radical resection by the neurosurgeon. The goal of radical surgical resection is cure in the case of low-grade brain tumors. However, even in those situations where surgery alone cannot be curative, the reduction of tumor bulk facilitates the task of both radiation therapy and chemotherapy, with improvement in progression-free survival as well as overall survival. For those tumors that cannot be cured by surgical resection alone, the standard of therapy thereafter still remains irradiation of the residual tumor. It is clear that the single major advance in the treatment of childhood medulloblastoma has been Cushing's recognition of the value of craniospinal irradiation. Refinements in radiation machines and treatment planning have permitted more accurate delivery of radiation therapy with a slight reduction in toxicity. Newer approaches, such as hyperfractionated irradiation and interstitial irradiation, attempt to improve therapeutic efficacy while minimizing toxicity. Nevertheless, as more children are surviving their brain tumors following surgery and radiation therapy, the price of the successful therapy is being increasingly realized in terms of developmental deficits, particularly in the very young child. It is the desire of all those involved in the management of children with primary brain tumors to seek alternative approaches to wide-field irradiation of the brain in children with high-grade tumors.