Cytochlor, Tetrahydrouridine, and External-Beam Radiation Therapy in Treating Patients With Cancer That Has Spread to the Brain

OBJECTIVES: Primary * Establish the safety and toxicity profile of cytochlor and H4U when given in combination with external-beam radiotherapy for 2 weeks after treatment with the drugs alone in the previous week. Secondary * Determine the effectiveness of H4U to inhibit systemic cytidine deaminase (CD) during the course of treatment with cytochlor and H4U. * Perform detailed pharmacokinetic studies to determine the levels of cytochlor and its metabolites in serum and in urine in weeks 1, 2, and 3 during treatment. OUTLINE: This is a dose-escalation study of cytochlor. Patients receive cytochlor IV and tetrahydrouridine (H4U) IV over 5 minutes on 3 days in week 1 and on days 1-5 in weeks 2 and 3. Patients also undergo external-beam radiotherapy 5 days a week in weeks 2 and 3 initiated 3-4 hours after infusions of cytochlor and H4U. Treatment may repeat in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed monthly for 3 months, every 3 months for 1 year, every 4 months for 1 year, every 6 months for 1 year, and then yearly thereafter.