本研究收集134 名治療部位為胸腔腫瘤的病患，共有1399 組導引之影像。採用兩種不同固定裝置，分別為 AIO 和BAG 系統。而取像模式分成每日照相組和每周照相組。AIO 有628 組影像，BAG 有771 組影像；其中每 日組及每周組分別為1024 組和375 組影像。不論何種固定裝置，每日與每周照相的平均位移量差異不大，約在 0.3 cm 左右(p 值皆<0.01)。最大的位移量是在每周組的BAG 上發生(ML 方向7.1 cm)，而其他方向的最大位移變 化也是發生在每周組的BAG。放射師在定位時可依病人狀況決定採用何種固定裝置，以達到良好的擺位重 現性。

This study collected 134 treatment chest tumor patients, a total of 1399 image-guided groups. Using two different immobilization systems, AIO and BAG systems, respectively. Image mode is divided into daily and weekly groups. AIO has 628 group images, and BAG has 771 group images. Daily and weekly groups have 1024 and 375 images respectively. Whether which of the immobilization system, the average displacement of daily and weekly groups which have little difference, for about 0.3 cm (p value<0.01). The maximum displacement occurs at the weekly BAG group (ML:7.1 cm).In the other direction, the weekly BAG group is also has maximum displacement. Radiologists decide which immobilization system to achieve the good positioning repeatability by following the patient's condition.