High-dose methotrexate with citrovorum factor rescue for the treatment of central nervous system tumors in children.

Eleven patients with brain tumors recurrent after surgery and radiation therapy were treated with high-dose methotrexate (MTX) (300-500 mg/kg) with citrovorum factor rescue (CFR). MTX was given as an iv infusion over 4 hours followed 2 hours later by oral CFR (10 mg every 6 hours X 12). MTX levels were measured in the serum, lumbar cerebrospinal fluid (CSF), and ventricular CSF at 0, 4, 12, 24, 48, and 72 hours from the start of the MTX infusion. MTX concentrations of greater than 10(-6) M were measured in the CSF over a period of 24 hours after the iv infusion. Peak CSF concentrations reached were greater than 10(-5) M. After the response to high-dose MTX with CFR was evaluated, vincristine (1.5 mg/m2) and a nitrosourea (methyl-CCNU or BCNU) were added to this treatment regimen. Two of four patients with recurrent pontine glioma and five of seven patients with recurrent medulloblastoma had favorable objective responses to treatment. It is suggested that high-dose MTX with CFR be cautiously considered for the primary treatment of intracranial neoplasms in children with the hope of increasing the cure rate for children with malignant brain tumors.