CLINICAL TRIAL / NCT01342354

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.