AstrocytomaBrain NeoplasmsGlioblastomaGliomaNimustineOligodendrogliomaSupratentorial NeoplasmsDacarbazineAntineoplastic Agents, AlkylatingOptic Nerve NeoplasmsBrain Stem NeoplasmsGliosarcomaKarnofsky Performance StatusLomustineChromosomes, Human, Pair 10Neoplasm Recurrence, LocalCarmustineProcarbazineCombined Modality TherapySurvival AnalysisMagnetic Resonance ImagingHypothalamic NeoplasmsDisease ProgressionPrognosisTumor Markers, BiologicalImmunohistochemistrySurvival RateTreatment OutcomeAntineoplastic AgentsTomography, X-Ray ComputedAntineoplastic Combined Chemotherapy Protocols