Feasibility of Four Consecutive High-Dose Chemotherapy Cycles With Stem-Cell Rescue for Patients With Newly Diagnosed Medulloblastoma or Supratentorial Primitive Neuroectodermal Tumor After Craniospinal Radiotherapy: Results of a Collaborative Study

PURPOSE: This study was designed to determine the feasibility and safety of delivering four consecutive cycles of high-dose cyclophosphamide, cisplatin, and vincristine, each followed by stem-cell rescue, every 4 weeks, after completion of risk-adapted craniospinal irradiation to children with newly diagnosed medulloblastoma or supratentorial primitive neuroectodermal tumor (PNET). PATIENTS AND METHODS: Fifty-three patients, 19 with high-risk disease and 34 with average-risk disease, were enrolled onto this study. After surgical resection, high-risk patients were treated with topotecan in a 6-week phase II window followed by craniospinal radiation therapy and four cycles of high-dose cyclophosphamide (4,000 mg/m2 per cycle), with cisplatin (75 mg/m2 per cycle), and vincristine (two 1.5-mg/m2 doses per cycle). Support with peripheral blood stem cells or bone marrow and with granulocyte colony-stimulating factor was administered after each cycle of high-dose chemotherapy. Treatment of average-risk patients ...