A randomized phase II trial to assess the efficacy and safety of selective metabolically adaptive radiation dose escalation in locally advanced non-small cell lung cancer receiving definitive chemoradiotherapy. Eligible and consenting patients will be randomized to receive conventional chemoradiotherapy or chemoradiotherapy with a radiation (RT) integrated boost. All patients will receive a fludeoxyglucose-positron emission tomography (FDG-PET) scan within two weeks prior to starting treatment. The primary outcome is to determine if dose escalation to metabolically active tumor subvolumes will reduce local-regional failure rate at 2 years.