中文摘要：

目的探讨自主呼吸控制（ABC）部分乳腺外照射（EB—PBI）不同呼吸状态选定银夹位移对术腔中全部银夹所构成几何体中心位移的影响。方法对本院行保乳术后ABC辅助EB—PBI的27例患者行适度深吸气呼吸控制（mDIBH）、深呼气呼吸控制（DEBH）、自由呼吸（FB）状态CT模拟定位扫描，并分别获得图像各2套。基于每套CT图像勾画术腔中全部银夹并形成以银夹为顶点的不规则几何体。图像间在自动配准基础上基于选定银夹手动配准，获得自动加手动配准时几何体中心三维方向上位移。用Kruskal—WallisH及Kolmogorov—SmirnovZ检验位移差异。结果mDIBH与mDIBH、FB与FB、DEBH与DEBH状态间几何体中心三维方向位移相似（H=0．00～1．76，P=0．184～0．954），而mDIBH与DEBH状态间则不同（Z=11．31—23．00，P=0．000～0．001）。mDIBH与mDIBH和mDIBH与DEBH间、FB与FB和mDIBH与DEBH间、DEBH与DEBH和mDIBH与DEBH间，4个选定银夹配准所对应的几何体中心位移在前后、头脚方向差异均不同（Z=4．76～25．54，P=0．000—0．029）。结论ABC辅助EB．PBI放疗分次内同一呼吸状态间银夹构成几何体各方向位移均相似，而两种极端呼吸状态间前后方向及头脚方向位移均不同。

英文摘要：

Objective To investigate the effect of the displacement of the selected silver clip in the different respiratory state achieved by active breathing control （ABC） system on the displacement of the geometry constituted by all of the silver clips at the border of the cavity in external-beam partial breast irradiation （EB-PBI）. Methods Two sets of CT images in state of moderate deep inspiratory breathing hold （mDIBH）, deep expiratory breathing hold （DEBH）, and free breath （FB） were acquired in the same CT simulation assisted by ABC system for each of the 27 patients after breast conservative surgery. All silver clips in the cavity were delineated based on each set of CT images. Thereafter, the irregular geometry based on the silver clips as the vertices was automatically formed. Four selected clips located at the top, bottom, lateral border and medial border of the cavity were correspondingly manually registered based on automatic registration of the CT images acquired in the same or different state of respiration including mDIBH, FB, and DEBH. The displacement of center of the geometry in the direction of right-left （RL）, anterior-posterior （AP）, and superior-inferior （SI） separately based on automatic registration and manual registration was evaluated. The difference of the displacement was analyzed by Kruskal-Wallis H-test and Kolmogorov-Smirnov Z-test. Results When registered between mDIBH and mDIBH, FB and FB, DEBH and DEBH, the differences of the displacement of the center of geometry were not statistically significant （H = 0. 00 - 1.76, P=0. 184 -0.954）. When registered between mDIBH and DEBH, the differences were statistically significant （Z = 11.31 -23.00, P = 0. 000 -0. 001 ）. There were statistically significant differences in the displacement of geometry center based on the selected silver clip between different registration forms in AP and SI directions （ Z = 4.76 - 25.54, P =0. 000 - 0. 029 ）. Conclusions The difference of intrafraction displacement of the geo