盆腔肿瘤常规放疗摆位误差分析

A Study of Conventional Radiotherapy Replacement Errors for Pelvic Tumor

目的通过重复摆位验证的测量数据分析,找出误差原因,提高放射治疗重复摆位的准确度。方法 20例接受盆腔放疗的患者通过真空固定袋仰卧于床上定位并拍摄定位片,进行等中心方式放疗,每周拍验证片,与原定位片比较,测量摆位误差。结果通过20例患者,共166张验证片和原始定位片相对比,X、Y、Z轴误差分别为(0.49±0.28)cm、(0.3±0.19)cm、(0.6±0.24)cm,正、侧面移位旋转为(6.9±2.5)°、(4.8±2.7)°。结论盆腔肿瘤放疗中重复摆位存在一定误差,误差产生的原因考虑与患者关节活动、年龄、胖瘦、放疗工作者的素质、设备质控等有关。

Objective To study the measure data of replacement errors,find out causation and improve the radiotherapy replacement locating accuracy. Methods Twenty patients with pelvic tumor who received radiotherapy,supine body position and take simulated locating film,treated with technology of source axis distance. Took the verification film for each patient from the first week to the end,and matched with the simulated locating film,measure data of replacement errors. Results Accorded to 166 times compare of verification film and simulated locating film in the 20 patient,we could conclude the replacement errors include X-axis,Y-axis, Z-axis were（ 0. 49 ± 0. 28） cm、（ 0. 3 ± 0. 19） cm,（ 0. 6 ± 0. 24） cm. Conclusion The replacement errors always occurs in the process of Radiotherapy for Pelvic tumor,it is perhaps caused by joint movement,age,responsibility of operator,QC of equipment etc.