Durvalumab (MEDI4736) With or Without SBRT in Clinical Stage I, II and IIIA Non-small Cell Lung Cancer

• 1. Patient has histologically or cytologically proven clinical stages I (tumors \> 2 cm), II, and IIIA NSCLC and is considered eligible for surgical resection with curative intent. Patients with 2 primary non-small cell lung cancers are allowed. 2. Measureable disease, as defined by RECIST v1.1. 3. Written informed consent and HIPAA obtained from the subject prior to performing any protocol-related procedures. 4. Age \> 18 years at time of study entry 5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. 6. Adequate normal organ and marrow function as defined below:
• Haemoglobin ≥ 9.0 g/dL
• Absolute neutrophil count (ANC) ≥ 1.5 x 109/L (\> 1500 per mm3)
• Platelet count ≥ 100 x 109/L (\>100,000 per mm3)
• Serum bilirubin ≤ 1.5 x institutional upper limit of normal (ULN). This will not apply to subjects with confirmed Gilbert's syndrome (persistent or recurrent hyperbilirubinemia that is predominantly unconjugated in the absence of hemolysis or hepatic pathology), who will be allowed only in consultation with their physician.
• AST (SGOT)/ALT (SGPT), and alkaline phosphatase ≤ 2.5 x institutional upper limit of normal (ULN).
• Serum creatinine CL\>40 mL/min by the Cockcroft-Gault formula (Cockcroft and Gault 1976) or by 24-hour urine collection for determination of creatinine clearance: 7. Evidence of post-menopausal status or negative urinary or serum pregnancy test for female pre-menopausal patients. Women will be considered post-menopausal if they have been amenorrheic for 12 months without an alternative medical cause. The following age-specific requirements apply: Women \<50 years of age would be considered post-menopausal if they have been amenorrheic for 12 months or more following cessation of exogenous hormonal treatments and if they have luteinizing hormone and follicle-stimulating hormone levels in the post-menopausal range for the institution or underwent surgical sterilization (bilateral oophorectomy or hysterectomy). Women ≥50 years of age would be considered post-menopausal if they have been amenorrheic exogenous hormonal treatments, had radiation-induced menopause with last menses \>1 year ago, had chemotherapy-induced menopause with last menses \>1 year ago, or underwent surgical sterilization (bilateral oophorectomy, bilateral salpingectomy or hysterectomy). 8. Subject is willing and able to comply with the protocol for the duration of the study including undergoing treatment and scheduled visits and examinations including follow up. 9. No prior therapy for their lung cancer.

Subjects should not enter the study if any of the following