Inclusion Criteria:

• Pathologically confirmed adenocarcinoma of the pancreas.
• Patients must have marginally resectable disease based on radiological and laparoscopic assessment; disease shows abutment (loss of fat plane and ≤ 180 degree involvement of the circumference of the vessel) of the celiac axis, hepatic artery, superior mesenteric vein [SMV]or artery [SMV] or disease that encases a short segment (normal vessel above and below amenable to reconstruction) of the hepatic artery or portal vein [PV] without extension to the celiac axis or judged to be marginally resectable by a surgeon for other reasons.
• Patients with biliary obstruction must have adequate drainage (biliary stent ≥ 9F or biliary bypass to maintain function until surgical resection) prior to starting chemoradiation.
• All patients must have radiographically assessable disease that is encompassable within a reasonable irradiation volume.
• Zubrod performance status 0-2 within 6 weeks prior to treatment.
• All patients will undergo pretreatment evaluation of tumor extent and tumor measurement per RECIST. Patients must complete all required testing as listed in section 4.

• Required pretreatment laboratory parameters:

  • absolute granulocyte/neutrophil count (AGC/ANC) ≥ 1.8 thou/mm3
  • platelet count ≥ 100,000/mm3
  • bilirubin < 2 mg/dl
  • ALT/SGPT < 3x upper limit of normal
  • creatinine < 3 mg/dl
  • calculated creatinine clearance > 30 mL/min
• Signed study specific, IRB stamped informed consent.
• Age ≥ 18 years at time of consent.
• The patient's nutritional and general physical condition must be considered compatible with the proposed treatment.
• cT1-3N0-1M0; stage 1a-2b.

Exclusion Criteria:

• Evidence of distant metastasis; evidence of metastatic disease in the major viscera (organs), peritoneal seeding and/or ascites.
• Previous irradiation to the abdomen that would compromise the ability to deliver the prescribed treatment.
• Prior surgical resection.
• Other malignancy (except non-melanoma skin cancer) that has not been disease-free for at least 5 years.
• Active, untreated infection.
• Serious medical, psychiatric and/or addictive illness that would preclude the consent process, treatment and/or follow-up compliance.
• Pregnant and/or breast-feeding women, or patients of child-producing potential not willing to use contraception while on treatment and for at least 3 months thereafter.
• Chemotherapy within 6 months prior to study.
• Gastroduodenal obstruction.