Assessing the Efficacy and Safety of Selective Metabolically Adaptive Radiation Dose Escalation in Locally Advanced Non-Small Cell Lung Cancer Receiving Definitive Chemoradiotherapy

Inclusion Criteria: * Patients who are at least 18 years old and are able to consent * Patients who will undergo Chemo-RT as primarily modality of treatment * Patients with a primary tumor or node measuring at least 10mm on CT scan * Patients with a PET avid tumor having Standardized Uptake Values (SUV) \> 4 * Patients with Eastern Cooperative Oncology Group (ECOG) status 0-2 within 4 weeks of randomization Exclusion Criteria: * Trimodality patients who have surgery as part of curative treatment * Previous radiotherapy to intended treatment volumes * Active invasive malignancy other than lung cancer * Active pregnancy * Poor respiratory function (Forced Expiratory Volume \< 1.0 or Diffusing Capacity \< 50% age-adjusted normal) * ECOG status \> 2 * Pre-treatment complete blood count/differential showing inadequate bone marrow reserve (absolute neutrophil count \< 1800 cells/mm3 or platelets \< 100 000 cells/mm3 or hemoglobin \< 90g/L), measured within 4 weeks of registration * AST, ALT or total bilirubin \> 2.5 times the upper limit of normal, measured within 4 weeks of registration * Unintentional weight loss \>10% over 3 months within 4 weeks of registration * Severe active co-morbidity defined by: * Significant history of uncontrolled cardiac disease; i.e. uncontrolled hypertension, unstable angina, myocardial infarction within the last 6 months, uncontrolled congestive heart failure, cardiomyopathy with decreased ejection fraction * Transmural myocardial infection requiring intravenous antibiotics at the time of registration * Chronic Obstructive Pulmonary Disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy within 30 days before randomization * Acquired immune deficiency syndrome (AIDS) based on the current Centre for Disease Control definition; note, however, that HIV testing is not required for entry into this protocol