Object-constrained meshless deformable algorithm for high speed 3D nonrigid registration between CT and CBCT

High-speed nonrigid registration between the planning CT and the treatment CBCT data is critical for real time image guided radiotherapy (IGRT) to improve the dose distribution and to reduce the toxicity to adjacent organs. The authors propose a new fully automatic 3D registration framework that integrates object-based global and seed constraints with the grayscale-based "demons" algorithm.Clinical objects were segmented on the planning CT...