4. Patients must have recovered from the acute toxic effects of all prior chemotherapy, immunotherapy, or radiotherapy, before entering the study and must be without significant systemic illness. Patients must not have received any systemic therapy for Leptomeningeal disease (LMD) within 3 wks (6 wks if a nitrosourea), intrathecal chemotherapy within 1 wk, or irradiation within 8 wks prior to treatment on this study. Patients previously receiving craniospinal irradiation must have positive cytology or progression of meningeal disease on MRI scan. Patients must not have received whole brain or focal CNS radiotherapy within 1 wk of treatment.