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

Thoracic malignancies (study group 1): Patients to be treated for gastro-esophageal junction (GEJ) malignancy undergo an implantation procedure of two or three radiopaque markers several days prior to treatment simulation, which are used to correct patient position at treatment. At treatment simulation, patients receive a standard CT scan followed by an RCCT scan. In cases of GEJ malignancy, oral contrast is administered prior to the standard CT scan; this is done at the treating physician's discretion. The standard CT is used to design the radiation treatment plan, where as the RCCT is used to define a volume that encompasses the motion extent of the tumor with breathing and is transferred to the standard CT.

Abdominal malignancies (study group 2): Patients undergo an implantation procedure of two or three radiopaque markers several days prior to treatment simulation. At treatment simulation, patients receive a standard CT scan followed by an RCCT scan. Intravenous contrast is administered prior to the standard CT; this is done at the treating physician's discretion.