Inclusion Criteria:

- Patients must have received radiotherapy for histologically confirmed nasopharyngeal
carcinoma.

- Prior irradiation >/= 6 months prior to study entry.

- Radiographic evidence to support the diagnosis of radiation-induced brain necrosis
without tumor recurrence.

- Age>/= 18 years. Because on dosing or adverse event data are currently not available
on the use of bevacizumab in patients <18years old.

- No prior bevacizumab therapy.

- No evidence of very high intracranial pressure that suggests brain hernia and needs
surgery.

- Fertile women who are willing to take contraception during the trial.

- Routine laboratory studies with bilirubin aspartate aminotransferase (AST or SGOT) < 2 * ULN, creatinine <1.5 * ULN, red-cell
count >/= 4,000 per cubic millimeter; white-cell count >/=1500 per cubic millimeter,
platelets >/= 75,000 per cubic millimeter; Hb >/=9.0. PT, APTT, INR in a normal
range.

- If with history of seizures, patients should be on anticonvulsant therapy. However,
preference will be enzyme-non-inducing anticonvulsants.

- Ability to understand and willingness to sign a written informed consent document.

- The patient has no active bleeding or pathological condition that carries a high risk
of bleeding; there is no evidence of serious or non-healing wound, ulcer or bone
fracture.

Exclusion Criteria:

- Patients with any of the following should be excluded: 1) evidence of metastatic
disease; 2)evidence of tumor invasion to major vessels(e.g. the carotid); 3) history
of bleeding related to tumor or radiotherapy during or after the completion of
radiation.

- Evidence of active central nervous system hemorrhage.

- History of abdominal fistula, gastrointestinal perforation or intra-abdominal abscess
within 28 days prior to study enrollment.

- inadequately controlled hypertension (systolic blood pressure (SBP) > 140 mmHg and/or
diastolic blood pressure (DBP) > 90 mmHg despite antihypertensive medication)

- Severe complications: 1) History of large vessel cerebrovascular accident (CVA)
within 6 months; 2) Myocardial infarction or unstable angina within 6 months; 3) New
York heart association grade II or greater congestive heart failure; 4) Serious and
inadequately controlled cardiac arrhythmia; 5) Significant vascular disease (e.g.
aortic aneurysm, history of aortic dissection); 6) Clinically significant peripheral
vascular disease; 7) severe infection.

- Evidence of bleeding diathesis or coagulopathy.

- Patients who have received steroid therapy for radiation-induced brain necrosis
before the study.

- History of anaphylactic response to bevacizumab.