Effects of Folfirinox and Stereotactic Body Radiation Therapy for Advanced Pancreatic Cancer

Inclusion Criteria: * Age \>/= 18 years * ECOG performance status 0-1 * Pathologic or clinical diagnosis of a new pancreatic adenocarcinoma. A reasonable attempt should be made to make a pathologic diagnosis of malignancy. * Imaging as follows: * CT scan of the chest, abdomen and pelvis with IV and oral contrast within 8 weeks of registration * Whole body PET scan within 8 weeks of registration * Evaluation by a surgical oncologist to determine non-resectability * Negative serum pregnancy test within 2 weeks prior to registration for women of childbearing potential. * CBC/differential obtained within 14 days prior to registration with adequate bone marrow function as follows: * ANC \> 1,500 cell/mm3 * Platelets \> 100,000 cells/mm3 * Hemoglobin \> 8.0 g/dl (transfusion to obtain this value is permissible) * Additional labs within 14 days prior to registration * CA 19-9 * Creatinine \<2mg/dl * Bilirubin \<2mg/dl * AST and ALT \< 2.5 x ULN * Patients must provide study specific informed consent prior to study entry. Exclusion Criteria: * Metastatic disease as defined by the multi-disciplinary team * Prior anti-cancer therapy for a pancreatic tumor * Prior malignancy within the last 3 years. * Pregnant women or lactating women * Acquired Immune Deficiency Syndrome (AIDS) based on CDC criteria. However HIV testing is not manditory for this protocol * Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects