在头颈部肿瘤放疗中 ,采用面罩固定可减少体位变动误差 ,提高摆位的重复性和治疗精度是不庸置疑的。但是 ,我们发现采用不同面罩标记法对摆位精度有不同影响。本文通过利用 CT模拟定位系统测量两种不同头颈部体位固定面罩标记法在重复摆位中的误差 ,以确定提高头颈部重复摆位准 Radiation in the treatment of head and neck cancer, the use of mask fixation can reduce the body position error, improve the repeatability and accuracy of positioning is beyond doubt. However, we found that using different mask marking methods has different effects on the placement accuracy. In this paper, by using the CT simulation positioning system to measure two different head and neck position fixed mask marking error in the repeated positioning in order to determine to improve the head and neck repeated positioning