Immunochemoradiotherapy in Patients With Pancreatic Cancer

Inclusion Criteria: Pancreatic adenocarcinoma proven by biopsy or cytology Locally advanced, unresectable disease with absence of distant metastatic disease. The presence of non-regional retroperitoneal or abdominal adenopathy is acceptable for inclusion. OR Borderline resectable pancreatic adenocarcinoma (any of the following): * Tumor abutment or encasement of a short segment of hepatic artery (without evidence of tumor extension to the celiac artery) that is amenable to resection and reconstruction * Tumor abutment of the superior mesenteric artery involving 180 degrees or less of the circumference of the artery and without encasement * Impingement or narrowing of the superior mesenteric vein/portal vein or short-segment (\< 2 cm) occlusion of the superior mesenteric vein, portal vein, or their confluence with a suitable option for vascular reconstruction * Eastern Cooperative Oncology Group(ECOG)Performance Status 0 or 1 * Ability to give informed consent and comply with the protocol * Women of childbearing potential must have a negative pregnancy test and must avoid becoming pregnant while on treatment. Men must avoid fathering a child while on treatment. * Patients with a history of psychiatric illness must be judged able to understand fully the investigational nature of the study and the risks associated with the therapy. Exclusion Criteria: * Age \< 18 years * History of other malignancy in the past 2 years except carcinoma in situ of the cervix or bladder, or non-melanomatous skin cancer * Previous chemotherapy or radiation therapy for pancreatic cancer or previous radiation therapy to the target field * Clinically active autoimmune disease or active infection * History of heart attack (within 90 days) or stroke (within 6 months), or presence of hypertension requiring change in blood pressure medications in the last 4 weeks, hypotension, uncontrolled arrhythmias, heart failure (New York Heart Association (NYHA) Functional Classification ≥ Class 2 in last 6 months), unstable angina or angina occurring during sexual activity. * Use of "nitrates" or nitroglycerin. * History of hereditary degenerative retinal disorders including retinitis pigmentosa. * Chronic systemic corticosteroid use at supra-physiologic doses (prednisone \> 10 mg a day or equivalent) * Use of recreational drugs called "poppers" like amyl nitrite and butyl nitrite. * Laboratory values (performed within 14 days prior to enrollment) as follows: * Neutrophil count \< 1500 cells/µL * Hemoglobin \< 9 gm/dL (patients may be transfused to establish eligibility) * Platelet count \< 100,000 cells/µL * Significant coagulopathy (INR \> 1.5) * Significant liver or renal dysfunction * Other medical or psychiatric conditions that in the opinion of the Principal Investigator would preclude safe participation in protocol.