Dose-Intensive Melphalan and Cyclophosphamide With Autologous Bone Marrow Rescue for Recurrent Medulloblastoma and Germ Cell Tumors

Study start date: September 1, 1994

DISEASE CHARACTERISTICS: Diagnosis of recurrent medulloblastoma or CNS germ cell tumor Histologic review of the primary intracranial or spinal cord tumor required Biopsy and reduction of tumor bulk prior to study encouraged but not required No more than 1 prior primary therapy (radiotherapy or chemoradiotherapy) and/or 1 prior salvage therapy Patients with progression on salvage therapy ineligible Minimal residual disease (tumor bulk no more than 1.5 cm) or in second clinical complete remission (CR) Bone marrow infiltration with or without mass lesions or isolated abnormal CSF cytology as the only manifestation of recurrent disease allowed if a clinical CR is first achieved with conventional therapy PATIENT CHARACTERISTICS: Age: 2 to 25 Performance status: Karnofsky 80-100% Life expectancy: More than 8 weeks Hematopoietic: Absolute neutrophil count greater than 1,000/mm^3 Platelet count greater than 100,000/mm^3 Hepatic: Bilirubin less than 1.5 mg/dL SGPT less than 80 IU Renal: Creatinine less than 1.2 mg/dL Cardiovascular: LVEF normal Other: No infection Able to tolerate vigorous hydration Not pregnant Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics Prior cyclophosphamide or ifosfamide allowed Endocrine therapy: No concurrent dexamethasone as an antiemetic Other concurrent corticosteroids allowed Radiotherapy: See Disease Characteristics Pretransplantation radiotherapy boost allowed Surgery: See Disease Characteristics Pretransplantation surgery allowed Other: At least 4 weeks since prior therapy except corticosteroids