The value of surveillance testing in childhood brain tumors.

Follow-up procedures in children with brain tumors are designed to confirm tumor response to initial therapy, identify recurrence or progression at the time of potential secondary treatment, and establish the patterns of failure. Serial use of neurologic examinations and computerized tomography scans are outlined for all tumor types. Tumors capable of subarachnoid metastasis (medulloblastoma, ependymomas, pineal/suprasellar germ cell tumors, and pineoblastoma) require periodic assessment of the neuraxis by cerebrospinal fluid (CSF) cytology and myelography to establish the frequency of subclinical meningeal seeding in study settings. Serial analysis of specific biochemical markers for medulloblastoma (CSF polyamines) and germ cell tumors (serum and CSF alpha-fetoprotein and beta-human chorionic gonadotropin) are suggested. Serial evoked potentials in brain stem gliomas are recommended.