Inclusion Criteria

        Subjects must meet all the following criteria:

          -  Histologic or cytologic documentation of NSCLC (all histologies allowed)

          -  Stage II or III disease (AJCC 7th Edition) based on imaging as required during
             screening: Stage II disease includes only subjects with medically inoperable N1
             disease otherwise meeting eligibility criteria. Primary tumor ≤ 7 cm

          -  Subjects with non-malignant pleural effusion identified on CT scan are eligible
             provided the effusion is not known or demonstrated to be an exudative effusion. If a
             pleural effusion is present, the following criteria must be met to exclude malignant
             involvement: A pleuracentesis is required if pleural fluid is present and visible on
             both CT scan and chest x-ray. Pleural fluid cytology must be negative for malignancy.
             Effusions that are minimal and too small for pleuracentesis as determined by the
             investigator will be eligible for enrollment.

          -  FEV1 ≥ 1.0 Liter or ≥ 40% predicted with or without bronchodilator within six months
             prior to initiation of study treatment. Subjects who meet the criterion without O2,
             but who need acute (started within 10 days prior to enrollment) supplemental oxygen
             due to tumor-caused obstruction/hypoxia are eligible, provided the amount of the O2
             needed has been stable.

          -  Age ≥18 years.

          -  ECOG performance status ≤ 2

          -  Subjects must have normal organ and marrow function as defined: Leukocytes ≥4,000/mcL;
             Absolute neutrophil count ≥1,500/mcL; Platelets ≥100,000/mcL; Total bilirubin ≤1.5
             times the upper limit of normal; Creatinine clearance ≥25 mL/min/1.73 m2

          -  Negative serum or urine pregnancy test prior to enrollment for women of childbearing
             age and potential.

          -  The effects of radiation on the developing human fetus are not well described. For
             this reason, women of child-bearing potential and non-sterilized men who are sexually
             active with a woman of child-bearing potential must agree to use adequate
             contraception (hormonal or barrier method of birth control; abstinence) prior to study
             entry and for the duration of study treatment. Should a woman become pregnant or
             suspect she is pregnant while she or her partner is participating in this study, she
             should inform her treating physician immediately.

          -  Ability to understand and the willingness to sign a written informed consent document.

        Exclusion Criteria

        Subjects must not meet any of the following criteria.

          -  Subjects who have had prior systemic therapy for lung cancer

          -  Subjects who have had prior radiation to the region of the chest that would result in
             overlap of radiation therapy fields and determined by the treating physician to impede
             the treatment of the study malignancy.

          -  Subjects who are actively being treated on any other interventional research study.

          -  Prior invasive malignancy unless disease free for a minimum of 3 years from
             enrollment. However, non-melanoma skin cancer, low risk prostate cancer, well
             differentiated thyroid cancers, in situ carcinomas of the breast, oral cavity, cervix,
             and other organs, and tumors that are not thought to impact the life expectancy of the
             subject according to the treating investigator is permissible.

          -  Centrally located primary tumor < 2 cm from involved nodal disease which would result
             in significant overlap of radiation dose. Centrally located is defined as within or
             touching the zone of the proximal bronchial tree, which is a volume 2 cm in all
             directions around the proximal bronchial tree (carina, right and left main bronchi,
             right and left upper lobe bronchi, intermedius bronchus, right middle lobe bronchus,
             lingular bronchus right and left lower lobe bronchi).