Lung cancer is the leading cause of cancer death in both men and women in the United States. In 2014, an estimated 224,210 men and women were diagnosed with carcinoma of the lung and bronchus, resulting in 159,260 deaths. Per the current National Comprehensive Cancer Network (NCCN) guidelines, the standard of care for early-stage non-small cell lung cancer (NSCLC) is lobectomy with lymph node dissection. Historically, medically inoperable early-stage NSCLC patients have been offered definitive external beam radiotherapy (EBRT) as primary management but, overall, studies have consistently shown poor patient outcomes. Stereotactic body radiation therapy (SBRT) is a technique which delivers very high doses of radiation per fraction over one to five fractions to precisely defined volumes with steep dose gradients. SBRT is commonly utilized for the treatment of biopsy-proven early stage NSCLC in the medically inoperable patient.