Temozolomide, Vincristine, and Irinotecan in Treating Young Patients With Refractory Solid Tumors

brain and central nervous system tumors, unspecified childhood solid tumor, protocol specific, recurrent childhood cerebellar astrocytoma, recurrent childhood cerebral astrocytoma, recurrent childhood brain stem glioma, recurrent childhood brain tumor, recurrent childhood ependymoma, recurrent childhood medulloblastoma, recurrent childhood supratentorial primitive neuroectodermal tumor, recurrent childhood visual pathway and hypothalamic glioma, childhood oligodendroglioma, childhood craniopharyngioma