Positron Emission Tomography (PET) Imaging in Stage III Non-small Cell Lung Cancer (PET START Trial)

Inclusion Criteria: * Histological or cytological evidence of NSCLC. Must have documented pathology report with histology indicated (e.g. squamous, adenocarcinoma, large cell, NSCLC not otherwise specified). * Stage III (mediastinal node positive) NSCLC based on conventional staging (e.g. computed tomography \[CT\] scan of chest and upper abdomen, CT or magnetic resonance imaging \[MRI\] of brain, bone scan). * Suitable for combined modality (chemotherapy and radiation) therapy or radical radiation therapy or trimodality therapy (chemotherapy, radiation and surgery). Exclusion Criteria: * Stage IV NSCLC (by conventional staging). * Small cell lung cancer. * Poor performance status Eastern Cooperative Oncology Group (ECOG) 3-4. * Poor pulmonary function precluding radical radiation therapy (Adequate pulmonary reserve for radical radiation therapy. Pulmonary function tests should have forced expiratory volume in 1 second (FEV1) \> 1.0 liter or \> 40% predicted, diffusing capacity of the lung for carbon monoxide (DLCO) \> 45% and/or predicted contralateral FEV1 \> 800 cc based on quantitative ventilation perfusion lung scan). * Significant concurrent medical problems (e.g. uncontrolled diabetes, active cardiac problems, significant chronic obstructive pulmonary disease). * Insulin dependent diabetic where requirements for PET imaging may be problematic. * Unable to lie supine for at least 30 minutes in radiation treatment position for imaging with PET. * Failure to provide informed consent. * Previous PET scan relating to recent cancer diagnosis prior to entry into study. * Pregnant or lactating females. * Prior thoracic radiation. * Prior malignancy within 3 years from randomization (except nonmelanotic skin cancer or carcinoma in situ of the cervix). * Administered more than two cycles of chemotherapy prior to radical radiation therapy or concurrent chemoradiation (as part of induction or sequential chemotherapy prior to randomization) for the current malignancy.