Accurate patient positioning is critical in Radiation Therapy. Electronic imaging is used to compare a patient's actual treatment position, with that which was planned from an initial CT scan. Radiation Therapists compare planned and actual images using analysis software to determine if differences are within acceptable tolerances. At the VIC, we use 3 different breast imaging protocols depending on the patient set-up and treatment technique. Findings from our recent retrospective planning study show that our current electronic imaging protocols miss some clinically significant patient set-up errors, particularly in the medial/lateral direction, and that these errors can be better detected with the use of an anterior image. The purpose of this study is to test these findings prospectively in clinical practice, through the direct comparison of our current protocols with a proposed new protocol, which would include an anterior electronic portal image (EPI).
