RADIOTHERAPY APPARATUS AND METHOD FOR DETERMINING TARGET POSITIONS USING RADIOTHERAPY APPARATUS

The present invention relates to a radiotherapy apparatus and a method for determining target positions using a radiotherapy apparatus, so as to accurately detect the motion of the tumor position. The method includes: a ray source locating in a first position, and emitting a radiation beam; a detector receiving the radiation beam emitted by the ray source at the first position, and generating first image data of the target according to the radiation beam emitted by the ray source at the first position; the ray source moving to a second position and emitting a radiation beam, wherein an interval at which the ray source moves from the first position to the second position is a positive integer multiple of a preset breathing cycle of a patient; the detector receiving the radiation beam emitted by the ray source at the second position, and generating second image data of the target according to the radiation beam emitted by the ray source at the second position; and determining position information of the target according to the first image data and the second image data.