Hypothesis/Rationale: Lung cancer is the number one cause of cancer-related mortality in both men and women in the United States, with over 170,000 cases diagnosed annually. The overall 5-year survival rate remains 14% despite decades of clinical research. Thoracic RT is the standard treatment for locally advanced (Stage III) NSCLC, in combination with chemotherapy in favorable patients. Metastatic lung cancer (Stage IV) is treated with systemic chemotherapy, with the addition of RT for palliation of tumor symptoms. Most lung cancers present as large tumors, measuring 2 to 7 cm in largest dimension. It is therefore not difficult to understand that only 16% of patients experience a complete resolution of their irradiated tumors within 3 months following a course of standard fractionated (2.0 Gy daily) RT and chemotherapy.