Comparison of Kilovoltage Cone-Beam Computed Tomography With Megavoltage Projection Pairs for Paraspinal Radiosurgery Patient Alignment and Position Verification

The setup corrections found using CBCT without the use of implanted markers were consistent with the marker registration on MV projections. CBCT has additional advantages, including better positioning precision and robust automatic three-dimensional registration, as well as eliminating the need for invasive marker implantation. We have adopted CBCT for the setup of all single-fraction paraspinal patients. Our data have also demonstrated that target displacements during treatment are insignificant.