Patent ID: 9724540
Date: 2017-08-08
CPC Classifications: A61B,A61N

Claim:
1. A moving body tracking device for radiation therapy, wherein said moving body tracking device is used for radiation therapy to treat a patient by irradiating said patient with a treatment beam, comprising: an X-ray image information acquisition circuit that acquires a position of a treatment target locus in a reference breathing phase and three-dimensional X-ray image data consisting of a group of two-dimensional X-ray image data of a region including the treatment target locus in multiple successive breathing phases from a storage device; an X-ray image deformation amount calculation circuit that calculates a deformation amount of a two-dimensional X-ray image including the treatment target locus between different breathing phases by performing image registration on the three-dimensional X-ray image data acquired from said storage device; a position calculation circuit that calculates positions of the treatment target locus in the respective breathing phases on a basis of the position of the treatment target locus in the benchmark reference breathing phase acquired from said storage device and the deformation amount of the two-dimensional X-ray image including the treatment target locus between the different breathing phases; a template matching circuit that performs acquiring X-ray images of the region including the treatment target locus in association with the multiple successive breathing phases, preparing templates on performing the tracking by setting parameters for template matching, and identifying the positions of the treatment target locus in the respective breathing phases by performing the template matching on the successively acquired X-ray images, multiple times by changing said parameters; and a comparison circuit that specifies error values between each parameter by comparing the positions of the treatment target locus in the respective breathing phases calculated by said position calculation circuit and the positions of the treatment target locus in the respective breathing phases, the positions being identified by the template matching circuit.