Study To Establish Maximum Tolerated Dose (MTD) of Cyberknife in Patients With Un-Resectable Pancreas Cancer (TL002)

Inclusion Criteria:

* Pathologically confirmed adenocarcinoma of the pancreas
* Unresectable disease based on the following imaging criteria (table 1)

  * extrapancreatic extension
  * tumor involvement of the SMA or celiac axis
  * evidence of occlusion of the SMV-portal vein confluence
* KPS \> 50 (ECOG 0-2)
* Age \>18 years
* Women of childbearing age and male participants must practice adequate contraception (hormonal or barrier method of birth control; abstinence) prior to and throughout study treatment.
* Life expectancy \> 3 months
* Ability to understand and the willingness to sign a written informed consent.
* Note that patients with metastatic disease are eligible if it is felt that the patients will benefit from local control of the primary disease.
* Disease that is measureable or evaluable for response endpoint per RECIST

Exclusion Criteria:

* Prior radiotherapy to the upper abdomen
* Resectable or borderline resectable pancreas cancer. Note that these patients are eligible for a separate study looking at radiosurgery for borderline resectable pancreas cancer
* Severe comorbidity rendering a candidate ineligible for chemotherapy or radiation, 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.
* Patients of childbearing age who are unwilling or unable to practice contraception
* Inability to undergo MRI or CT with contrast for treatment planning
* Patients may not be receiving any other investigational nor commercial agents with therapeutic intent to treat pancreatic cancer while on this trial. Note that patients can have had previous investigational therapy but cannot have this concurrently with this protocol treatment.