Constrained non-rigid registration using Lagrange multipliers for application in prostate radiotherapy

This paper presents a novel free-form deformation registration algorithm with non-rigid constraints to capture the transformation between the planning day and treatment day CT images used for external beam radiotherapy for prostate cancer. The non-rigid registration is constrained to the predetermined motion of segmented soft tissues, and the constrained optimization problem is solved by the method of Lagrange multipliers. The ultimate goal is...