Acknowledging that level I evidence already exists regarding the general beneficial impact on FDG PET in the staging and subsequent management of lung cancer the investigators postulate that fusing PET/CT data sets with RT CT simulation data sets for adult patients with conventionally/clinically assessed stage III non-small cell lung cancer will have a significant impact on GTV as well as normal tissue irradiation. This research will also estimate inter and intra-observer variability of treatment planning, relative to GTV, between and amongst radiation oncologists.