摘要
目的:探讨CTVision在鼻咽癌调强放射治疗中摆位误差的监测,为鼻咽癌制定放疗计划CTV外扩PTV提供参考依据。方法:鼻咽癌患者以热塑膜固定头颈部,激光灯摆位,行调强放疗前采用西门子CTVision图像引导放疗系统的千伏级CT扫描仪扫描,系统自动将扫描图像与治疗计划CT图像匹配,并计算出患者x(左右)、y(头脚)、z(腹背)方向上摆位误差数据。调整治疗床,修正摆位误差。结果:统计80例患者在x、y、z方向上系统误差(均数)±随机误差(标准差)分别为(-0.56±1.65)mm、(-0.22±2.90)mm、(-0.45±1.89)mm,所有误差均小于3 mm。结论:通过对本组数据分析,鼻咽癌三维适形调强放疗有一定误差。基于CTVision图像分析在线修正方法能减少摆位误差,并有助于确定CTV的合理处方。
Objective To study the role of CTVision on the geometrical accuracy of IMRT of nasopharyngeal carcinoma to calculate CTV referential safety margins of PTV.Methods Immobilization and alignment were performed by conventional head-and-neck masking and laser alignment for daily positioning with the Siemens CTVision system.All patients had received kilo-voltage computed tomography（KV-CT） before radiotherapy was delivered.The set-up error of isocenter position on x,y,z was obtained by matching KV-CT and plan CT images.The patient setup was then corrected by moving the couch accordingly.Results According to 88 KV-CT scans,the systemic±random error on x,y,z directions were（-0.56±1.65）mm,（-0.22±2.90）mm and（-0.45±1.89）mm.All errors were less than 3mm.Conclusion Based on this data,there is some extent of setup error in nasopharyngeal carcinoma 3D CRT or IMRT.The approach based on the CTVision measurements can be used to reduce the impact of setup error obviously and to estimate the required margins for PTV.
出处
《医疗卫生装备》
CAS
2011年第10期84-85,共2页
Chinese Medical Equipment Journal
关键词
鼻咽癌
摆位误差
CTVision
计划靶区
nasopharyngeal carcinoma
setup error
CTVision
planning target volume
