AstrocytomaBrain NeoplasmsGlioblastomaGliomaDacarbazineNimustineOligodendrogliomaSupratentorial NeoplasmsAntineoplastic Agents, AlkylatingOptic Nerve NeoplasmsGliosarcomaBrain Stem NeoplasmsKarnofsky Performance StatusNeoplasm Recurrence, LocalLomustineChromosomes, Human, Pair 10CarmustineCombined Modality TherapyProcarbazineSurvival AnalysisMagnetic Resonance ImagingDisease ProgressionPrognosisImmunohistochemistryTumor Markers, BiologicalAntineoplastic AgentsHypothalamic NeoplasmsSurvival RateTreatment OutcomeCell Line, TumorAntineoplastic Combined Chemotherapy ProtocolsTomography, X-Ray ComputedRetrospective StudiesTumor Cells, CulturedDrug Administration Schedule