Optical Surface Sensing and Multimodal Image Fusion for Position Verification in Radiotherapy

A method for the analysis and visualization of patient motion in radiotherapy is proposed. Motion parameters are derived from two image modes: data from an optical sensor and of an electronic portal imaging device which are synchronized. Fusion of both image modes increases robustness of estimation of the real patient motion because both image modes provide different motion parameters with sufficient accuracy. Spatial transformation parameters yield by registration of portal images with digitally reconstructed radiographs (DRR) and of surface data obtained from optical sensor with those obtained from CT.