Unsupervised learning for deformable registration of thoracic CT and cone‐beam CT based on multiscale features matching with spatially adaptive weighting

Purpose Cone‐beam computed tomography (CBCT) is a common on‐treatment imaging widely used in image‐guided radiotherapy. Fast and accurate registration between the on‐treatment CBCT and planning CT is significant for and precise adaptive radiotherapy treatment (ART). However, existing CT–CBCT registration methods, which are mostly affine or time‐consuming intensity‐ based deformation registration, still need further study due to the considerable...