Locally Advanced Pancreatic Cancer Treated With ABLAtivE Stereotactic MRI-guided Adaptive Radiation Therapy

Inclusion Criteria:

1. Locally advanced pancreatic adenocarcinoma or adenosquamous carcinoma as defined byNCCN guidelines.
2. Minimum of 4 months interval from chemotherapy start to administration of the lastdose/chemo.
3. Minimum 8 cycles of (m)FOLFIRINOX OR 12 doses of gemcitabine/nab - paclitaxel)
4. No radiographic evidence of local or distant disease progression at any time prior tostudy enrollment after starting chemotherapy
5. At least 18 years of age
6. ECOG performance status ≤ 1
7. Adequate bone marrow and organ function as defined below:
8. Absolute neutrophil count ≥ 1,000/mcL
9. Platelets ≥ 75,000/mcL
10. Hemoglobin ≥ 8.0 g/dL
11. Total bilirubin ≤ 1.5 x IULN
12. AST(SGOT)/ALT(SGPT) ≤ 3.0 x IULN
13. Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence) prior to study entry and forthe duration of study participation. Should a woman become pregnant or suspect she ispregnant while participating in this study, she must inform her treating physicianimmediately.
14. Ability to understand and willingness to sign an IRB approved written informed consentdocument (or that of legally authorized representative, if applicable).

Exclusion Criteria:

1. CA19-9 > 180 U/mL within 30 days of randomization.
2. Any prior abdominal radiation therapy.
3. History of prior malignancy with the exception of: 1) malignancy treated with curativeintent and with no known disease for at least 2 years from treatment to studyenrollment, 2) adequately treated carcinoma in situ without evidence of disease (i.e.superficial bladder cancer).
4. Currently receiving any other investigational agents.
5. More than one cytotoxic regimen given for pancreatic cancer.
6. Major abdominal surgery within 4 weeks prior to randomization.
7. Definitive surgery for pancreas cancer completed prior to study enrollment (e.g.,Whipple procedure).
8. Subject with planned or scheduled definitive surgery for pancreas at time of studyenrollment
9. Grade 3 or greater toxicity during induction chemotherapy that has not resolved to atleast grade 2
10. Uncontrolled intercurrent illness including, but not limited to, ongoing or activeinfection, symptomatic congestive heart failure, unstable angina pectoris, or cardiacarrhythmia.
11. Pregnant and/or breastfeeding. Women of childbearing potential must have a negativepregnancy test within 14 days of study entry.
12. Medical/psychological contraindication to having an MRI scan.