Inclusion Criteria:

- Patients must have histologically confirmed diagnosis of WHO grade IV primary
malignant glioma (glioblastoma multiforme or gliosarcoma). Patients have to be able
to undergo a GTR.

- Age > or = 18 years

- Evidence of a unilateral, single focus of measurable central nervous system (CNS)
neoplasm on contrast-enhanced MRI, unless medically contraindicated (CT scan will
then be used)

- Patients must have < or = 2 disease progressions

- An interval of at least 4 weeks from the end of prior radiotherapy or one week from
the end of a cycle of chemotherapy and enrollment on this protocol

- Karnofsky > or = 70%

- Hemoglobin > or = 9.0 g/dl, absolute neutrophil count (ANC) > or = 1,500
cells/microliters, platelets > or = 125,000 cells/microliters

- Serum creatinine < or = 1.5 mg/dl, serum glutamic-oxaloacetic transaminase (SGOT) and
bilirubin < or = 1.5 times upper limit of normal

- Patients on corticosteroids must have been on a stable dose for 1 week prior to
entry, if clinically possible, and the dose should not be escalated over entry dose
level

- If patient received chemotherapy or investigational agent as part of their prior
therapy, the patient must recover from all toxicities (> or = Grade 1) prior to
enrollment on this protocol

- Signed informed consent approved by the Institutional Review Board

- No evidence of CNS hemorrhage on the baseline MRI or CT scans

- If sexually active, patients will take contraceptive measures for the duration of
treatment as stated in the informed consent

Exclusion Criteria:

- Pregnancy or breast feeding. Women of childbearing potential must have a negative
serum pregnancy test within 72 hours prior to treatment administration

- Multifocal disease

- Prior treatment with Gliadel

- Prior treatment with CPT-11 or Avastin

- Prior stereotactic radiosurgery or brachytherapy

- Co-medication that may interfere with study results; e.g. immuno-suppressive agents
other than corticosteroids

- Active infection requiring IV antibiotics

- Acute or chronic renal insufficiency (a glomerular filtration rate (GFR) <30
mL/min/1.73m2) or acute renal insufficiency of any severity due to hepato-renal
syndrome or in the peri-operative liver transplantation period

- Inability, in the opinion of the study investigator, to comply with study and/or
follow-up procedures

- Current, recent (within 4 weeks of the first infusion of this study), or planned
participation in an experimental drug study other than a Genentech-sponsored Avastin
cancer study

- Life expectancy of less than 12 weeks

- Active malignancy, other than superficial basal cell and superficial squamous (skin)
cell, or carcinoma in situ of the cervix within last five years

- Inadequately controlled hypertension (defined as systolic blood pressure >150 and/or
diastolic blood pressure > 100 mmHg)

- Prior history of hypertensive crisis or hypertensive encephalopathy

- New York Heart Association (NYHA) Grade II or greater congestive heart failure

- History of myocardial infarction or unstable angina within 6 months prior to Day 1

- History of stroke or transient ischemic attack within 6 months prior to Day 1

- Significant vascular disease (e.g., aortic aneurysm, requiring surgical repair or
recent peripheral arterial thrombosis) within 6 months prior to Day 1

- History of hemoptysis (> or = 1/2 teaspoon of bright red blood per episode) within 1
month prior to Day 1

- Evidence of bleeding diathesis or significant coagulopathy (in the absence of
therapeutic anticoagulation)

- Major surgical procedure, open biopsy, or significant traumatic injury within 28 days
prior to Day 1 or anticipation of need for major surgical procedure during the course
of the study

- Core biopsy or other minor surgical procedure, excluding placement of a vascular
access device, within 7 days prior to Day 1

- History of abdominal fistula, gastrointestinal perforation within 6 months prior to
Day 1

- Serious, non-healing wound, active ulcer, or untreated bone fracture

- Proteinuria at screening as demonstrated by urinalysis (urine protein)

- Known hypersensitivity to any component of Avastin

- Pregnancy (positive pregnancy test) or lactation. Use of effective means of
contraception (men and women) in subjects of child-bearing potential