A Fast Nonrigid Registration Algorithm for Adaptive Radiotherapy

摘要

In Adaptive Radiotherapy information about changes in patient geometry at the moment of treatment compared to the planning data is required for repositioning or treatment plan adaption. Using state of the art procedures like rigid or stereotactical registration, translations and rotations of the whole patient can be considered. However, more complex deformations need to be taken into account whenever conformity needs to be inreased. Taking place directly before treatment, adaption should take as little time as possible. Therefore the algorithm presented here combines a Free Form Deformation model that allows for fast local interpolation of the translation vectorfield and a two step template matching approach for fast local translation detection. An evaluation with four data sets has shown that computation times are acceptable and mean residual errors are below the voxel dimensions.