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, BiologicalPrognosis