Treatment Of Recurrent Central Nervous System Primitive Neuroectodermal Tumors (PNETs) In Children And Adolescents A Strategy Including The Use Of High Dose Thiotepa And High Dose Carboplatin

OBJECTIVES:

• Determine the feasibility of cyclophosphamide and surgical resection or radiotherapy followed by thiotepa, carboplatin, and autologous peripheral blood stem cell rescue in patients with recurrent medulloblastoma or supratentorial neuroectodermal and pineal tumors.
• Determine the acute and chronic toxicity of this regimen in these patients.
• Determine progression-free and overall survival of patients treated with this regimen.

OUTLINE: This is a multicenter study.

• Cytoreductive Phase: Patients receive cyclophosphamide IV over 1 hour on days 1 and 2 and filgrastim (G-CSF) subcutaneously (SC) once daily beginning on day 7 and continuing until blood counts recover. Treatment repeats after discontinuation of G-CSF for 2-4 courses. Peripheral blood stem cells (PBSC) are harvested after each course of cyclophosphamide. Patients undergo surgical resection or radiotherapy after the completion of chemotherapy. Patients achieving complete response proceed to myeloablative therapy.
• Myeloablative Phase: Patients receive thiotepa IV over 3 hours on days 1-3. Autologous PBSC are reinfused on day 5 and patients receive G-CSF SC once daily beginning on day 10 and continuing until blood counts recover. Beginning 2 days after the completion of G-CSF, patients receive carboplatin IV over 1 hour on days 1-3. Autologous PBSC are reinfused on day 5 and patients receive G-CSF SC once daily beginning on day 10 and continuing until blood counts recover.

Patients are followed at 1, 3, 6, and 12 months.