Patient description: The patient is a 41-year-old man and a known case of Acromegaly who underwent transsphenoidal surgery 4 months ago. He came to the clinic for the follow up lab studies after his primary resection surgery. His lab study shows the IGF-1 level of 4.5 ULN adjusted by sex and age. His random GH level is 4 ug/L. The recent brain MRI confirmed the residual pituitary tumor. His past medical history is only significant for acromegaly due to pituitary adenoma and the recent surgery. After his surgery he takes only vitamin D and multivitamins.

Clinical trial eligibility criteria: eligible ages (years): 3.0-21.0,  Glial Cell Tumors Malignant Gliomas Glioblastoma Multiforme Anaplastic Astrocytoma Gliomatosis Cerebri Gliosarcoma Brainstem Glioma Patient must be greater than or equal to 3 years and less than or equal to 21 years of age at the time of study enrollment. 2. Patients must have histologic verifications of a glioblastoma multiforme, anaplastic astrocytoma, gliomatosis cerebri (WHO grade III or IV glioma with diffuse parenchymal and/or leptomeningeal involvement), or gliosarcoma at the time of study enrollment. Patients with newly diagnosed intrinsic brainstem gliomas, defined as tumors with a pontine epicenter and diffuse rather than focal involvement of th pons, with or without extension to adjacent medulla or midbrain, are eligible without histologic confirmation. Patients with brainstem tumors that do not meet these or not considered to be typical intrinsic pontine gliomas will only be eligible if the tumors are biopsied and proven to be a grade III or IV glioma (anaplastic astrocytoma, glioblastoma multiforme, gliosarcoma). 3. Patients must have Karnofsky Performance Score (for patients greater than 16 years of age) or Lansky Performance Score (for patients less than or equal to 16 years of age) greater than or equal to 50% assessed within two weeks of study enrollment. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score. 4. Patients must not have received any prior chemotherapy, radiation therapy, biologic therapy, or bone marrow transplant. Surgery and dexamethasone are permitted prior to study entry. In patients who require anti-convulsant prior to study entry, it is permissible to start VPA, but trough VPA concentration must be repeated within 48 hours of study entry. 5. Patients must have adequate bone marrow function defined as Hgb greater than or equal to 8 gm/dL (transfusion independent) Platelet count greater than or equal to 100,000/mm3 (transfusion independent) Absolute neutrophil count (ANC) greater than or equal to 1,000/ mm3 6. Patients must have adequate liver function defined as Bilirubin (sum of conjugated + unconjugated) less than or equal to 1.5 times institutional upper limit of normal (ULN) for age SGPT (ALT) less than or equal to 2.5 times institutional ULN for age Serum albumin greater than or equal to 2 g/dL. 7. Patients must have adequate renal function defined as Urine protein (albumin)/creatinine ratio of less than 1.0 Creatinine clearance or radioisotope GFR greater than or equal to 70 ml/min/1.73m2 OR A serum creatinine based on age and gender as follows  Females of reproductive potential must not be pregnant or lactating. Males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method. 2. Patients with active or history of cardiac (CHF, myocardial infarction, myocarditis) disease are excluded from this trial. 3. Patients receiving any of the following medications are not eligible for study entry: a. Anti-cancer therapy or investigational agents b.Anti-coagulants (except for heparin to maintain the patency of central venous catheters). c.Growth factors for white blood cell, red blood cell or platelet support d.Aspirin (> 81 mg/day) e.Non-steroidal anti-inflammatory drugs f.Clopidogrel (Plavix), Dypiramidole (Persantine), or any other drug that inhibits platelet function g. Anti-convulsants: patients on any anti-convulsant with the exception of VPA are eligible for study entry. It is strongly recommended that a neurology consult be obtained to enable discontinuation of all anti-convulsant other than VPA, whenever possible. 4. Patients who have an uncontrolled infection are not eligible. 5. Patients with inadequately controlled systemic hypertension (SBP and/or DBP greater than 95th percentile for age and height) 6. Patients with a prior history of hypertensive crisis and/or hypertensive encephalopathy If a BP measurement prior to registration is greater than 95th percentile for age and height, it must be rechecked and documented to be less than 95th percentile for age and height prior to registration. If a patient falls between the height or weight percentiles, site should average the value as appropriate. For patients greater than or equal to 18 years, use adult normal ranges for blood pressure. Patients with hypertension are eligible if their blood pressures become less than 95th percentile after anti hypertensive medications. 7. Prior Ischemic Events: Patients with a history of stroke, myocardial infarction, or unstable angina within 6 months prior to registration are not eligible. 8. Vascular Disease: Patients with significant vascular disease (e.g., aortic aneurysm requiring surgical repair or recent peripheral arterial thrombosis) within 6 months prior to registration will not be eligible. 9. Patients with a history of hemoptysis, bleeding diathesis, known platelet disorder, or coagulopathy are not eligible. 10. Patients with a history of abdominal fistula or GI perforation within 6 months prior to registration are not eligible. 11. Patients with a known or suspected urea cycle or other metabolic disorder are not eligible. 12. Patients with abnormality of the tibial metaphyseal plate on plain X-ray prior to study entry are not eligible. 13. Patients with a history of a serious non-healing wound, ulcer, or bone fracture are not eligible. 14. Patients with any clinically significant systemic illness, including serious infection, pulmonary, hepatic, or other organ impairment, that would compromise tolerance and/or timely completion of protocol therapy. 16. Patients who, in the opinion of the investigator, may not be able to comply with the safety monitoring requirements and/or follow-up studies of this trial. 17. Patients with a known hypersensitivity to any component of bevacizumab are not eligible for this trial