Mafosfamide in Treating Patients With Progressive or Refractory Meningeal Tumors

DISEASE CHARACTERISTICS: * Diagnosis of leukemia or lymphoma with meningeal involvement defined as cerebrospinal fluid cell count at least 5/mm\^3 AND evidence of blast cells on cytospin preparation or by cytology OR * Diagnosis of other solid tumor with meningeal involvement defined as presence of tumor cells on cytospin preparation or cytology OR presence of measurable meningeal disease on CT or MRI scan * Meningeal malignancy must be progressive or refractory to conventional therapy * Meningeal malignancies secondary to an underlying solid tumor are allowed at initial diagnosis provided there is no conventional therapy * No concurrent bone marrow relapse in leukemia or lymphoma patients * No clinical evidence of obstructive hydrocephalus or compartmentalization of the cerebrospinal fluid flow as documented by a radioisotope indium In 111 or technetium Te 99-DTPA flow study * Patients demonstrating restored flow after focal radiotherapy are allowed PATIENT CHARACTERISTICS: Age: * Over 3 Performance status: * ECOG 0-2 Life expectancy: * At least 8 weeks Hematopoietic: * Not specified Hepatic: * No clinically significant liver function abnormalities Renal: * No clinically significant renal function abnormalities Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 6 months after study * No clinically significant metabolic parameter abnormalities (e.g., electrolytes, calcium, and phosphorus) * No significant systemic illness (e.g., infection) PRIOR CONCURRENT THERAPY: Biologic therapy: * Recovered from prior immunotherapy Chemotherapy: * At least 1 week since prior intrathecal chemotherapy (2 weeks for cytarabine (liposomal)) and recovered * Concurrent systemic chemotherapy to control systemic or bulk CNS disease allowed with the following exceptions: * No phase I agent * No agent that significantly penetrates the CNS (e.g., high-dose systemic methotrexate (more than 1 g/m\^2), high-dose cytarabine (more than 2 g/m\^2), IV mercaptopurine, fluorouracil, topotecan, or thiotepa) * No agent known to have serious unpredictable CNS side effects Endocrine therapy: * Not specified Radiotherapy: * See Disease Characteristics * Recovered from prior radiotherapy * At least 8 weeks since prior craniospinal irradiation * Local radiotherapy for symptomatic or bulky CNS disease must be given prior to induction therapy * No concurrent whole brain or craniospinal irradiation * Concurrent partial brain (e.g., base of brain) or limited-field spinal radiotherapy for asymptomatic bulky (radiographically visible) CNS disease allowed * Total CNS radiotherapy dose must not exceed accepted safe tissue tolerances Surgery: * Not specified Other: * At least 1 week since any prior CNS therapy * At least 7 days since prior intrathecal investigational agent * At least 14 days since prior systemic investigational agent * No other concurrent intrathecal or systemic investigational agent * No other concurrent intrathecal or systemic therapy to treat meningeal malignancy * No other concurrent intrathecal therapy or agent that significantly penetrates the blood-brain barrier * No concurrent agent known to have serious unpredictable CNS side effects