Using FDG-PET During Radiation Therapy in Non-Small Cell Lung Cancer

Inclusion Criteria: * Patients must have FDG-avid and pathologically proven non-small cell lung cancer. If pathology not definitive, the patient needs to have a clinically diagnosed non-small cell lung cancer, which is also FDG-avid. * Patients must be 18 years of age or older. * Patients must have Karnofsky performance score \> 60. * Patients must have clinical AJCC (American Joint Committee on Cancer) Stage I-IIIB, with unresectable or inoperable disease. * Patients must have no evidence of a malignant pleural or pericardial effusion * Patients must have hemoglobin \> 10 gm/dl. Transfusions or medications may be used to achieve this criterion. * Patients must have reasonable organ and marrow functions as defined below if chemotherapy is considered: * WBC (White Blood Cell) \> 3,000/mm3. * absolute neutrophil count ≥ 1,500/mm3. * platelets \> 100,000/mm3 * total bilirubin ≤ 3.0 mg/dl. * AST ( Aspartate Aminotransferase or SGOT) and ALT (Alanine Transaminase or SGPT) \< 4 X institutional upper limit of normal. * creatinine ≤ 2.0 mg/dl. * Patients must not have serious intercurrent diseases per the judgment of the treating physician. * Patient must be willing to use effective contraception if female with reproductive capability. * Patients must be informed of the investigational nature of this study and given written informed consent in accordance with institutional and federal guidelines. Exclusion Criteria: * Patients with any component of small cell lung carcinoma are excluded from this study. * Prior radiotherapy to the thorax such that composite radiation would significantly overdose critical structures, either per estimation of the treating radiation oncologist or defined by failure to meet normal tissue tolerance constraints. * Pregnant women are excluded from this study because radiation has the potential for teratogenic or abortifacient effects. * Prisoners are excluded for this study.