This study's primary objective is to assess the efficacy of a treatment regimen involving Stereotactic Body Radiation Therapy (SBRT) delivered to the primary tumor followed by concurrent mediastinal chemoradiation by evaluating the proportion of subjects with locally-advanced non-small cell lung cancer (NSCLC) stage II/III who are alive and progression free at 12 months, and to compare to relevant historical controls. Additionally, the treatment regimen will be evaluated based on progression free survival, overall survival, radiologic clinical complete response rate following completion of therapy, objective response rate as defined by RECIST v 1.1, local and locoregional control, patterns of failure, and quality of life. Safety and exploratory objectives will include the rate of grade 2+ radiation pneumonititis and grade 3+ pulmonary events, while PFS, OS, QOL and toxicities will be compared between subjects receiving proton or photon mediastinal radiotherapy. Differential expression of cytokines and chemokines associated with radiation therapy will be determined.