High-Dose Chemotherapy Plus Autologous Stem Cell Transplantation Compared With Intermediate-Dose Chemotherapy Plus Autologous Stem Cell Transplantation With or Without Isotretinoin in Treating Young Patients With Recurrent High-Grade Gliomas

RATIONALE: Drugs used in chemotherapy, such as carboplatin, thiotepa, and etoposide, work in different ways to stop tumor cells from dividing so they stop growing or die. Combining chemotherapy with autologous stem cell transplantation may allow the doctor to give higher doses of chemotherapy drugs and kill more tumor cells. Isotretinoin may be effective in preventing recurrence of glioma. It is not yet known which regimen of chemotherapy plus autologous stem cell transplantation with or without isotretinoin is more effective in treating recurrent high-grade glioma. PURPOSE: This randomized phase III trial is studying high-dose chemotherapy or intermediate-dose chemotherapy followed by autologous stem cell transplantation to see how well it works compared to high-dose chemotherapy or intermediate-dose chemotherapy followed by autologous stem cell transplantation and isotretinoin in treating young patients with recurrent high-grade glioma.