AstrocytomaBrain NeoplasmsGlioblastomaGliomaNimustineOligodendrogliomaSupratentorial NeoplasmsDacarbazineAntineoplastic Agents, AlkylatingSurvival RateOptic Nerve NeoplasmsBrain Stem NeoplasmsGliosarcomaNeoplasm Recurrence, LocalKarnofsky Performance StatusLomustineSurvival AnalysisChromosomes, Human, Pair 10CarmustineCombined Modality TherapyProcarbazineTreatment OutcomePrognosisMagnetic Resonance ImagingDisease ProgressionRetrospective StudiesTumor Markers, BiologicalHypothalamic NeoplasmsImmunohistochemistryAntineoplastic Combined Chemotherapy ProtocolsAntineoplastic AgentsCell SurvivalTomography, X-Ray ComputedDrug Administration ScheduleDisease-Free SurvivalSpinal Cord Neoplasms