Combination Chemotherapy and Radiation Therapy in Treating Patients With Germ Cell Tumors in the Brain

DISEASE CHARACTERISTICS: * Clinical and radiological evidence of intracranial germ cell tumor, classified as 1 of the following: * Germinoma * Pure germinoma * Germinoma with mature and/or immature teratoma * Secreting germ cell tumor * Elevated tumor markers in serum and/or cerebral spinal fluid as evidenced by any of the following: * Alpha-fetoprotein \> 25 ng/mL * β-human choriogonadotropin \> 50 IU/L * Any tumor containing 1 of these components: * Yolk sac tumor * Choriocarcinoma * Embryonal tumor * Normal tumor markers allowed * Diagnosis confirmed by histology or elevated serum markers * Metastatic or nonmetastatic disease * Two separate tumors in the suprasellar and pineal areas without evidence of metastatic disease elsewhere are considered nonmetastatic multifocal disease * Study treatment must begin ≤ 4 weeks after diagnosis * No pure immature or mature teratomas * The following additional patients are eligible: * Patients who are \> 18 years of age provided no other appropriate protocol exists * Patients who were diagnosed \> 4 weeks ago * Patients who are in relapse PATIENT CHARACTERISTICS: * Not specified PRIOR CONCURRENT THERAPY: * No prior treatment except surgery * No concurrent amino glycosides or other nephrotoxic drugs during ifosfamide administration * No concurrent growth factors * No other concurrent chemotherapy or radiotherapy