AstrocytomaHypothalamic NeoplasmsOptic Nerve NeoplasmsThalamic DiseasesBrain NeoplasmsCerebellar NeoplasmsAntineoplastic ProtocolsOptic ChiasmHypothalamus, AnteriorNeurofibromatosis 1CraniopharyngiomaSupratentorial NeoplasmsProto-Oncogene Proteins B-rafGliomaComparative Genomic HybridizationMagnetic Resonance ImagingInfratentorial NeoplasmsGlioblastomaAnaplasiaBrain Stem NeoplasmsOligodendrogliomaGangliogliomaGenes, Neurofibromatosis 1EpendymomaNeurofibromin 1Cranial Nerve NeoplasmsCentral Nervous System NeoplasmsSpinal Cord Neoplasms