改进激光标志对真空垫固定体位食管癌放疗摆位误差和摆位时间的影响

Affect of set-up error and set-up time with vacuum bag immobilization by improving the laser mark in radiotherapy for esophageal cancer

目的:分析改进激光标志对于采用真空袋体位固定的食管癌患者放疗摆位误差和摆位时间的影响,探讨其临床应用价值。方法:将200例真空垫体位固定的食管癌放疗患者随机分成两组,一组采用传统激光标志方法,一组采用改进的标识方法。通过治疗机的电子影像装置(EPID)拍摄位置验证图像,与计划系统生成的标准射野数字重建图像(DRR)比较,分析两组病人X轴(左右方向)、Y轴(头脚方向)、Z轴(前后方向)摆位误差的大小,用秒表记录两组患者的摆位时间。结果:改进组与传统组相比,X轴方向和Z轴方向摆位误差显著减小,两组数据差异有统计学意义(P<0.05),Y轴方向摆位误差相近,无统计学意义(P>0.05);摆位时间,改进组明显小于传统组,且有统计学意义(P<0.05)。结论:改进激光标志可以减小真空垫固定体位的食管癌患者放疗摆位误差,提高了摆位重复性,缩短了摆位时间,推荐临床使用。

Objective：To analyze the improving laser mark for vacuum bag immobilization of patients with esophageal cancer radiotherapy set-up error and set-up time,and to explore its clinical value.Methods：All 200 patients with esophageal carcinome with vacuum pad immobilization,were randomly divided into two groups,a group of traditional laser marking method,a group using the improved methods of identification.Position verification image taken by the treatment machine＇s electronic imaging device（EPID）.To compare standard radiation field digitally reconstructed images（DRR）with the planning system to generate.Analyze the patients with X-axis（left and right direction）,Y-axis（the direction of head and feet）,the Z-axis（forward and backward directions） the size of the set-up error.Results：Improvement group compared with the traditional group,X-axis direction and Z-axis set-up error significantly reduced.The two sets of data difference was statistically significant（P0.05）,Y-axis set-up error was similar（P0.05）.set-up time：in improvement group was significantly less than the traditional group,（P0.05）.Conclusion：To improve the laser mark can reduce the fixed position of the vacuum cushion esophageal carcinoma set-up error,improve set-up repeatability,reducing set-up time.