Patient-based low dose cone beam CT acquisition settings for prostate image guided radiotherapy treatments on a varian TrueBeam linear accelerator.

To evaluate the performance of low dose Cone beam computed tomography(CBCT) acquisition protocols for image guided radiotherapy of prostate cancer.

Cone beam CBCT images of patients undergoing prostate cancer radiotherapy were acquired with the settings currently used in our department and two low dose settings at 50 and 63% lower exposure.