OligodendrogliomaAstrocytomaBrain NeoplasmsChromosomes, Human, Pair 19Chromosomes, Human, Pair 1LomustineGliomaSupratentorial NeoplasmsProcarbazineGangliogliomaSpinal Cord NeoplasmsGlioblastomaDacarbazineOncogene Proteins v-erbBEpendymomaAntineoplastic Agents, AlkylatingIsocitrate DehydrogenaseCerebral Ventricle NeoplasmsLoss of HeterozygosityChromosomes, Human, Pair 10Magnetic Resonance ImagingVincristineIn Situ Hybridization, FluorescenceGlial Fibrillary Acidic ProteinHypothalamic NeoplasmsNeoplasm GradingFatal OutcomeChromosome DeletionPrognosisCombined Modality TherapyImmunohistochemistry