Use of High-dose Radiation Therapy Plus Chemotherapy to Improve the Likelihood of Surgical Treatment in Patients With Locally Advanced Pancreatic Cancer

Inclusion Criteria: * Histologically or cytopathologically confirmed adenocarcinoma of the pancreas. * Locally advanced, unresectable pancreatic cancer defined on post-induction chemotherapy CT as having tumor involvement of \>180° (\> 50%) of the circumference of the superior mesenteric artery (SMA) or celiac axis, unreconstructable superior mesenteric vein (SMV) or PV involvement. * No evidence of distant metastasis either prior to or after induction chemotherapy. * Completion of at least 3 months of standard induction chemotherapy for LAPC, which may include FOLFIRINOX or gemcitabine and nab-paclitaxel, within 6 weeks of enrollment. * For patients currently receiving investigational agents, a washout of at least 2 weeks or 5 half-lives of experimental agent are required prior to the start of RT. * Age ≥18 years. * KPS 70-100. * Patients must have acceptable organ and marrow function as defined below: * Leukocytes \>3,000/µL * Absolute neutrophil count \>1,500/µL * Platelets \>75,000/µL * Total bilirubin Within 2 x upper limit of normal * AST (SGOT)/ALT (SGPT) \<2.5 x institutional upper limit of normal Creatinine Within 1.5 x upper limit of normal, OR Creatinine clearance \>60 mL/min for patients with creatinine levels above institutional normal * Any systemic therapy associated toxicity should be Grade 1 or less * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: * Patients who have borderline resectab…