Antineoplastic Agents/therapeutic use; Central Nervous System Neoplasms/drug therapy; Central Nervous System Neoplasms/metabolism; ErbB Receptors/metabolism; Quinazolines/therapeutic use; Adolescent; Antineoplastic Agents/adverse effects; Antineoplastic Agents/pharmacokinetics; Blotting, Western; Central Nervous System Neoplasms/pathology; Central Nervous System Neoplasms/surgery; Child; Child, Preschool; Ependymoma/drug therapy; Ependymoma/metabolism; Ependymoma/surgery; ErbB Receptors/antagonists & inhibitors; Female; Glioma/drug therapy; Glioma/metabolism; Glioma/pathology; Glioma/surgery; Humans; Infant; Lapatinib; Male; Medulloblastoma/drug therapy; Medulloblastoma/metabolism; Medulloblastoma/surgery; Neoplasm Grading; Quinazolines/adverse effects; Quinazolines/pharmacokinetics; Treatment Outcome; Young Adult