Positron Emission Tomography and Computed Tomography in Planning Treatment for Patients Undergoing 3-Dimensional Conformal Radiation Therapy for Non-Small Cell Lung Cancer That Cannot Be Removed by Surgery. ICORG 06-35

Pilot Study- Primary Objectives: * Prospective evaluation of the technical feasibility of integrating PET-CT fusion in St Luke's Hospital * Rate of PET-CT Scan based treatment delivery Pilot Study- Secondary Objectives: -Comparison of GTV, PTV and OAR DVHs between conventional 3-DCRT plan and PET-CT based 3-DCRT plan. Phase II Study- Primary Objective: -The safety of PET-CT scan based radiotherapy, with regard to loco-regional disease control. Phase II Study- Secondary Objectives: -Comparison of GTV, PTV and OAR DVHs between conventional 3-DCRT plan and PET-CT based 3-DCRT plan.