Deformable registration with excessive deformation correction for lung lesions

Deformable registration is essential to map the radiotherapy plan onto treatment images of the patient. However, deformable registration may introduce excessive deformation into tumor volume, shape and location. In this paper, our proposed registration method aims to correct the local excessive deformation on tumor while retaining the global correspondence by conventional registration method. To trace the excessive tumor change, automatic landmark correspondence is established on the basis of genus zero surface conformal mapping to recover the tumor information and its surrounding structures. Our experimental validation on clinical PET volumes and CT volumes demonstrated that our registration method was able to construct global correspondence for the input volumes and in the meantime maintain the correct and meaningful tumor information.