ABSTRACT
Online adaptive radiation therapy (ART) allows real-time treat-ment adaptations based on the current patient anatomy and geometry. In a typical online ART process, a computed tomography (CT) image is usually acquired prior to the treatment course for treatment planning purposes. Before each treatment fraction, a cone-beam CT (CBCT) image is then obtained, on which the treatment plan is redesigned to account
CONTENTS 11.1 Introduction 165 11.2 e Original Demons Algorithm 168 11.3e DISC Algorithm 168 11.4Implementation of DISC 170 11.5 Evaluation 171
11.5.1Synthetic Data: MC Simulation 171 11.5.2Clinical Data 172 11.5.3Quantication of Registration Performance 172
11.6 Results 173 11.6.1Synthetic Data 173 11.6.2Clinical Cases 174 11.6.3Eect of Patch Size 178 11.6.4Computational Eciency 178
11.7Discussion and Conclusions 179 References 181
for setup errors, deformations of tumor and other organs, and the change of their relative locations. Deformable image registration (DIR) technique plays an important role in this process in establishing a correspondence between voxels in the CT and the CBCT for various purposes, for instance, transferring the organ contours from the planning CT images to the daily CBCT images. It is, hence, desirable to have an accurate and robust DIR algorithm to facilitate this step.
