OligodendrogliomaLomustineBrain NeoplasmsChromosomes, Human, Pair 1Chromosomes, Human, Pair 19ProcarbazineAstrocytomaGliomaVincristineDacarbazineAntineoplastic Agents, AlkylatingCombined Modality TherapySupratentorial NeoplasmsAntineoplastic Combined Chemotherapy ProtocolsGangliogliomaSpinal Cord NeoplasmsOncogene Proteins v-erbBIsocitrate Dehydrogenase