This purpose of this study is to determine the highest tolerated dose of Stereotactic Body Radiation Therapy (SBRT) and also to determine the appropriate dose for intact pancreatic cancer.

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.

Adverse events as specified in the protocol to meet the definition of dose-limiting toxicity or acute adverse events were monitored for only one month. Serious adverse events ( late GI toxicity) were followed for up to 12 months after treatment. All-cause mortality was assessed over a longer period, which in this case was until death for all enrolled patients and up to 8 years.