AstrocytomaBrain NeoplasmsGlioblastomaGliomaOligodendrogliomaNimustineSupratentorial NeoplasmsDacarbazineOptic Nerve NeoplasmsAntineoplastic Agents, AlkylatingBrain Stem NeoplasmsGliosarcomaHypothalamic NeoplasmsLomustineKarnofsky Performance StatusChromosomes, Human, Pair 10Neoplasm Recurrence, LocalCarmustineProcarbazineCombined Modality TherapyMagnetic Resonance ImagingSurvival AnalysisSpinal Cord NeoplasmsDisease ProgressionImmunohistochemistryTumor Markers, BiologicalPrognosisTomography, X-Ray ComputedAstrocytesSurvival RateAntineoplastic AgentsTreatment OutcomeAnaplasiaDrug Administration ScheduleCerebellar NeoplasmsTumor Cells, CulturedEpendymomaCentral Nervous System NeoplasmsAntineoplastic Combined Chemotherapy ProtocolsRetrospective Studies