Evaluation of Daily CT Scans Using CT on Rails for Localization in the Treatment of Prostate Cancer

OBJECTIVES:

Primary

• Validate the software for CT-on-rails™ by comparing prostate target localization via daily ultrasound vs computed tomography (CT) in patients undergoing radiotherapy for prostate cancer.

Secondary

• Determine the potential benefit of using fiducials in the prostate of patients undergoing daily CT scans and/or ultrasounds for localization.
• Determine the intra- and inter-radiation treatment setup and target position uncertainties, in terms of isocenter coordinates in space, using both the ultrasound and CT scans compared to the coordinates of the isocenter determined at simulation, in these patients.