Comparison of Daily Prostate Positions during Conformal Radiation Therapy of Prostate Cancer Using an Integrated CT-linear Accelerator System: In-room CT Image versus Digitally Reconstructed Radiograph

The purpose of this study is to quantify the magnitudes of the position shifts of internal structures together with the correlation between the day-to-day positioning of the prostate and the bony anatomy using an integrated CT-linear accelerator system for external beam radiation therapy for prostate cancer.