A Study of a Retroviral Replicating Vector Combined With a Prodrug Administered to Patients With Recurrent Malignant Glioma

Inclusion Criteria: * at least 18 years of age * for intratumoral cohorts, supratentorial HGG (WHO grade III or IV) * technically unresectable HGG * initial definitive therapy such as surgery with or without adjuvant radiation * subject elected not to undergo treatment with Gliadel wafer * if receiving corticosteroids, dose is stable or decreasing for past 7 days * KPS: at least 70 * absolute neutrophil count \> 1500/mm\^3 * absolute lymphocyte count \> 500/mm\^3 * platelet count \> 100,000/mm\^3 * hemoglobin \> 10 g/dL * for intratumoral cohort, coagulation profile favorable to surgery * estimated glomerular filtration rate \> 50 mL/min * ALT \< 3 times ULN and bilirubin \< 1.5 mg/dL * negative serum pregnancy test Exclusion Criteria: * cytotoxic therapy within the past 4 weeks (6 weeks for BCNU/CCNU) * more than 2 recurrences including present recurrence * Gliadel wafer or wafers implanted within the past 8 weeks * taking more than 8 mg of dexamethasone per day * for intratumoral cohorts, injection of tumor would require violation of ventricular system * any infection requiring antibiotic, anticoagulant, or antiplatelet agents within the past 4 weeks * for intratumoral cohort, bleeding diathesis or use of anticoagulants/antiplatelet agents that cannot be stopped * allergy or intolerance to 5-FC * HIV positive * g.i. condition that would prevent ingestion or absorption of 5-FC * any investigational treatment within the past 30 days * pregnant or breast feeding * received Avastin * history of prior malignancy, excluding basal or squamous cell carcinoma of the skin, with an expected survival of less than 5 years.