Study of Neoadjuvent Chemotherapy Followed by SBRT in Patients With Resectable and Borderline Resectable Pancreatic Cancer

Primary Objectives: 1\. To assess one-year local control rates in patients with operable PDAC who receive neoadjuvant chemotherapy and SBRT Secondary Objectives: 1. To assess the following disease control endpoints: pathological response, disease-free survival, overall survival, failure pattern (local vs. distant) and time to development of distant metastases 2. To assess safety of the SBRT regimen Exploratory objectives 1. To obtain exploratory data correlating tumor response grade with changes in circulating tumor DNA levels following chemotherapy, SBRT, and surgery in patients with PDAC 2. To obtain exploratory data correlating circulating tumor DNA (ctDNA) changes with disease control endpoints (overall survival, disease-free survival, failure pattern, and time to development of distant metastases) 3. To obtain exploratory data on positron emission tomography (PET) and magnetic resonance imaging (MRI) findings and correlations with tumor response among patients treated on study.