上段食管癌旋转容积调强放射治疗计划的验证

摘要

Objective:To study the application suitability of RapidArc for upper esophageal cancer. Methods:To use 0. 6 cm3 finger ionization chamber and COMPASS three - dimensional dose verification system,10 cases of upper esophageal cancers on the RapidArc plans for absolute dose and relative dose was verified. The differences of irradia-tion dose and volume in target,lungs and spinal cord were evaluated with dose - volume histograms. To verify the posi-tion error by cone beam CT ended after radiotherapy,once a week,total of three times. Results:The center absolute dose of upper esophageal cancer accurate rates were above 98% . GTV,PTV - CTV,spinal cord and double lung γpass rate reached to 97% . The difference of D95% and Dmean ,in the majority of between two percent and three percent, which of GTV,CTV - GTV,PTV - CTV. Spinal cord D1% difference of 2. 28% . The left and right lung V10 ~ 30 and Dmean variation were within 2% . The mean position error of pre - post,head - foot,left - right direction was within 2% . Conclusion:RapidArc is applicable in the up esophageal cancer radiotherapy.%目的：分析旋转容积调强计划在上段食管癌放射治疗中的适应性。方法：应用0.6cm3指形电离室和 COMPASS 三维剂量验证系统分别对10例上段食管癌旋转容积调强计划进行绝对剂量和相对剂量的验证。应用剂量体积直方图比较靶区、肺和脊髓照射剂量和体积的差异。锥形束 CT 验证放疗后摆位误差，每周一次，共做三次。结果：等中心处绝对剂量精确率均达98％以上。GTV、PTV - CTV、脊髓和双肺γ通过率均达97％以上，GTV、CTV - GTV、PTV - CTV D95％、Dmean 的差异多数处于2％~3％之间，脊髓 D1％差异为2.28％。左肺和右肺 V10-30、Dmean的差异在2％以内。前后、头脚、左右方向的位置误差均值在2％以内。结论：旋转容积调强技术在上段食管癌放疗中是适用的。