Evaluation of Respiratory Motion-Corrected Cone-Beam CT in Radiation Treatment of Thoracic and Abdominal Cancers

Tumors must be seen clearly on CT scan to be radiated completely and safely. Breathing causes tumors to move. If the tumor moves during breathing, it can look blurred on the CT scan. This makes it difficult to see on CT scan. The investigators wish to investigate whether a new computer method makes tumors less blurry and easier to see on CT scan. Cone-beam CT is a type of CT scanner attached to the radiation treatment machine that produces 3D images of the patient. Since your tumor can move because of your normal breathing, it is often blurry and difficult to see accurately in a standard cone-beam CT scan. The investigators intend to use a computer method which processes the cone-beam CT data in a way that reduces the blurring and makes the tumor easier to see.