发泡胶枕在鼻咽癌调强放疗中的应用

目的:应用MVCT研究鼻咽癌放疗中个体化发泡胶枕与标准聚氨酯头枕两种不同固定方式的摆位精度。方法:选取鼻咽癌螺旋断层调强放疗患者共34例，分为试验组和对照组，分别采用个体化发泡胶枕和标准化聚氨酯头枕，结合头颈肩热塑网膜进行体位固定。两组患者每次放疗前行MVCT扫描并与定位CT在线匹配，对得出的两组摆位误差数据行独立样本t检验，并以线性误差3 mm和旋转误差2°为限定阈值，对两组摆位误差数据行χ2检验。结果:对照组在左右、上下、前后三个方向的摆位线性误差和绕这三个方向形成的旋转误差分别为（1.79±2.05）mm、（1.82±1.36）mm、（1.48±1.77）mm和（0.94±1.23）°、（1.15±1.08）°、（0.54±0.61）°；试验组在上述的摆位误差和旋转误差分别为（1.19±1.09）mm、（1.24±0.97）mm、（0.91±0.89）mm和（0.71±0.79）°、（0.99±0.79）°、（0.67±0.68）°，两组在上述方向比较P=0.00、0.00、0.00、0.00、0.01、0.00，两组超出误差限定阈值次数的比较，除绕前后方向的旋转误差无统计学意义（P>0.05），其余各方向均有意义（P<0.05）。结论:采用个体化发泡胶枕对鼻咽癌患者进行体位固定，摆位精度优于标准化聚氨酯头枕。

Application study of styrofoam pillow in intensity modulated radiotherapy for nasopharyngeal carcinoma

Objective:To compare the set-up errors between personalized styrofoam pillow and polyurethane pillow in radiotherapy for nasopharyngeal carcinoma by using the MVCT.Methods:Thirty-four patients with nasopharyngeal carcinoma were included in this study and separated into experimental group and the control group.The experimental group was immobilized with styrofoam pillow and thermoplastic mask.The control group was immobilized with polyurethane pillow and thermoplastic mask.MVCT scan and auto-match with the reference image online were regularly performed before the treatment.The independent sample t test was carried out between the two methods.Chi-square test was carried out on translation errors greater than 3 mm and rotation errors greater than 2 degree.Results:The linear errors and the rotation errors of the control group in left-right，up-down，front-back direction were （1.79±2.05）mm，（1.82±1.36）mm，（1.48±1.77）mm and（0.94±1.23）°，（1.15±1.08）°，（0.54±0.61）°，respectively.The linear errors and the rotation errors of the experimental group were（1.19±1.09）mm，（1.24±0.97）mm，（0.91±0.89）mm and（0.71±0.79）°，（0.99±0.79）°，（0.67±0.68）°，respectively (P=0.00，0.00，0.00，0.00，0.01，0.00，respectively).There was significant deference in left-right and up-down direction between experimental group and the control group(P<0.05).Conclusion:The immobilization techniques with personalized styrofoam pillow would be better than the techniques with polyurethane pillow in reducing the setup errors.