SU-E-I-20: Megavoltage and Kilovoltage Cone-Beam Computed Tomography Image Guidance for Lung Radiotherapy

PURPOSE: To evaluate the geometric accuracy of patient set‐up in lungcancerradiotherapy using daily megavoltage cone‐beam computed tomography (MV‐CBCT) image guidance, and compare this with kilovoltage (kV)‐CBCT image guidance performed under a similar protocol. Methods: Set‐up accuracy using MV‐CBCT was analyzed in eleven lungcancer patients (246 fractions). The MV‐CBCT and CT planning data sets were matched on‐line by a radiation oncologist …