Key problems in the management of children with brain tumors.

Steady progress has been made in the clinical management of children with brain tumors. Better diagnostic methods and more efficient surgical, radiotherapeutic, and chemotherapeutic techniques have evolved singly and in various combinations. These advances have at times created problems in patient management; for example, interpretation of clinically inexplicable signal changes on magnetic resonance imaging. Equally substantive, and at a more basic level, is the fact that understanding of the nature of the various tumors remains elusive in many cases. Some lesions seem to behave more like maldevelopments than neoplasms. Specific markers for any of the several tumor types have not been identified. The isochromosome i(17q), found in some malignant pediatric brain tumors, is also present in children with other conditions, both benign and malignant. Fundamental research is hampered by the difficulty in establishing cell lines for even the medulloblastoma, the most common of the frankly malignant group. Until these problems are supervened, important advances will largely remain at the clinical and morphologic level. Close coordination and careful correlation of data among the several members of the pediatric neuro-oncology team is essential for success. Clinical trials of combined modality care especially require well-reasoned rationales and careful definition of objectives, and must include meticulous evaluation of the late effects of therapy in survivors.