| 摘要 |
PROBLEM TO BE SOLVED: To mitigate an error in a deviation between a patient's present position and a position at the time of treatment planning, by performing positioning suitable for a characteristic of each part by using a plurality of evaluation functions.SOLUTION: Radiotherapy treatment patient automatic positioning includes the steps of: acquiring a two-dimensional DRR by reproducing, in performing registration of three-dimensional CT image data having been acquired at the time of treatment planning and a two-dimensional X-ray fluoroscopy image acquired at the time of positioning, X-ray photography geometry in a computer in order to perform alignment between the three-dimensional CT image data and the two-dimensional X-ray fluoroscopy image, and virtually performing perspective projection on the CT image data; and calculating a deviation between a patient's present position and a position at the time of treatment planning by searching for a shortest path to optimize a perspective projection parameter on rotation/parallel displacement of the CT image data so as to maximize the degree of agreement between the DRR and the X-ray fluoroscopy image. The radiotherapy treatment patient automatic positioning evaluates the degree of agreement between the DRR and the X-ray fluoroscopy image, on the basis of registration using a mutual information amount and edge detection algorithm.SELECTED DRAWING: Figure 10 |
