The research of respiratory movement induced hepatic tumor motion in radiotherapy by use of a cone-beam CT under the fluoroscopic mode

抄録

The characteristics of the hepatic tumor movement caused by respiration were evaluated by using fluoroscopy in this study. Motion signal curves of the tumor and apex were derived from fluoroscopic images acquired under the Motion View Mode on cone beam CT installed on an Elekta Synergy-S accelerator. The curves showed the relationship between the tumor and the diaphragm movement caused by respiration. Measurements showed motion of the tumor was closely related to that of the diaphragm caused by respiration. For the same patient, the periods and the ranges of the respiration were only slightly dissimilar among different fractions. On one hand, the patients could hold breath to minimize the extent of tumor motion. On the other hand, the tumor motion can be deduced from the motion of a marker affixed to the patients' skin. It is possible to reduce the influence of motion uncertainty by investigating the respiration to make treatment planning more accurate.