DISEASE CHARACTERISTICS:

• Diagnosis of neoplastic meningitis secondary to leukemia, lymphoma (including AIDS-related lymphoma), or solid tumor (including primary CNS tumors or carcinomas of unknown primary site), defined by 1 of the following criteria:

  • Cerebral spinal fluid (CSF) cell count > 5/μL AND evidence of blast cells on cytospin or by cytology (for patients with leukemia or lymphoma)
  • Presence of tumor cells on cytospin or cytology OR unequivocal presence of meningeal disease by MRI (for patients with solid tumor)

• No conventional therapy for neoplastic meningitis exists

  • Patients with CNS leukemia or lymphoma must be refractory to conventional therapy, including radiotherapy (i.e., second or greater relapse)
• Patients with CNS leukemia or lymphoma must have had a negative bone marrow aspiration within the past 2 weeks
• No clinical evidence of obstructive hydrocephalus
• No compartmentalization of CSF flow by radioisotope indium In 111 or technetium Tc 99 DTPA flow study
• No ventriculoperitoneal or ventriculoatrial shunt unless patient is completely shunt-independent
• No impending spinal cord compression or other CNS involvement (e.g., acute visual loss secondary to optic nerve involvement) requiring emergent local radiotherapy

PATIENT CHARACTERISTICS:

Age

• 3 to 21

Performance status

• Lansky 60-100% (≤ 16 years of age) OR
• Karnofsky 60-100% (> 16 years of age)

Life expectancy

• Not specified

Hematopoietic

• Not specified

Hepatic

• Not specified

Renal

• Calcium ≥ 7 mg/dL

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Sodium 125-150 mmol/L
• Magnesium ≥ 0.7 mmol/L
• Must have or be willing to have an intraventricular access device (i.e., Ommaya reservoir)

• No uncontrolled infection

  • HIV-positive patients with AIDS-related lymphomatous meningitis are eligible
• No other significant uncontrolled systemic medical illness that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Recovered from prior biologic therapy or immunotherapy

Chemotherapy

• Recovered from prior chemotherapy
• At least 1 week since prior intra-colony stimulating factory (CSF) chemotherapy (2 weeks for liposomal cytarabine)
• At least 3 weeks since prior systemic chemotherapy for leptomeningeal disease

• Concurrent systemic chemotherapy to control systemic disease or bulk CNS disease allowed provided the systemic chemotherapy is not an investigational agent OR any of the following:

  • High-dose (> 1 g/m^2) methotrexate
  • High-dose (> 1 g/m^2) cytarabine
  • Fluorouracil
  • Capecitabine
  • Thiotepa
  • Nitrosoureas
  • Topotecan

Endocrine therapy

• Not specified

Radiotherapy

• See Disease Characteristics
• At least 8 weeks since prior craniospinal radiotherapy and recovered

• No concurrent CNS radiotherapy

  • Concurrent radiotherapy to extra-CNS sites (e.g., painful bone metastases not in the craniospinal axis) allowed

Surgery

• Not specified

Other

• More than 2 weeks since prior and no other concurrent investigational agents
• No other concurrent intra-CSF or systemic therapy for leptomeningeal disease