Inclusion Criteria:

- Patients must have histologically confirmed, unresected cancer of the pancreas or
ampulla. The cancer may include any invasive histology (e.g. adenocarcinoma,
neuroendocrine carcinoma).

- Patients must have measurable radiographic disease.Patients with previous complete
resection are only eligible if there is measurable radiographic disease which is
clearly felt to represent locally recurrent disease.

- Patients may receive any number of cycles of chemotherapy prior to treatment with
SBRT, but not within 2 weeks of the first fraction of RT.

- Age > or = 18 years.

- Eastern Cooperative Oncology Group (ECOG) performance status < or = 2 (Karnofsky > or
= 60%)

- Life expectancy of greater than 3 months.

- Patients must have normal organ and marrow function.

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

Exclusion Criteria:

- Concurrent investigational therapy delivered over the period of treatment or
observation (28 days post-RT) for dose limiting toxicity.

- Prior radiation therapy to the abdominal area which would overlap with the proposed
area of treatment.

- Pregnancy.

- Primary disease > 7.5 cm in largest diameter as measured by CT or MRI.

- Gross extension of tumor into the lumen of the duodenum.

- Uncontrolled intercurrent illness including, but not limited to ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements.

- Use of bevacizumab or vascular endothelial growth factor inhibitor chemotherapy
within 3 months before RT or 6 months after RT.