应用KV-CBCT分析鼻咽癌调强放射治疗的摆位误差  

Setup Error in Intensity Modulated Radiotherapy for Nasopharyngeal Carcinoma by Kilo-Volt Cone-Beam Computed Tomography

作　　者：邢宝继 陈林[1] 郭汝涛[1] 刘世伟[1] 冉浩男 

机构地区：[1]哈尔滨医科大学附属肿瘤医院放疗科,黑龙江哈尔滨150081

出　　处：《现代生物医学进展》2014年第35期6953-6955,6959,共4页Progress in Modern Biomedicine

摘　　要：目的:应用KV-CBCT分析鼻咽癌调强放射治疗时的摆位误差,为鼻咽癌调强放射治疗计划设计时CTV外扩PTV边界的大小提供参考。方法:选取30例IMRT的鼻咽癌患者,治疗过程中每周一次应用KV-CBCT采集患者治疗前的CT图像,将所得图像与定位CT图像进行匹配,分别测定X、Y、Z轴三个方向的摆位误差。结果:30例患者共拍摄168次KV-CBCT,获得168组摆位误差结果,群体摆位误差分别为X轴-0.15±1.43 mm,Y轴0.20±1.58 mm,Z轴-0.21±1.65 mm;根据Van Herk公式计算得到各方向的CTV-PTV外放边界值X、Y、Z轴分别为3.1 mm、3.3 mm和3.4 mm。结论:应用KV-CBCT影像系统可实时测量摆位误差并在线进行纠正,减小摆位误差,为CTV-PTV外放边界提供参考。Objective： To analyze the setup errors by KV-CBCT in nasopharyngeal carcinoma treated with Intensity Modulated Radiotherapy to provide the reference for calculate safety margins of PTV with CTV. Methods： 30 patients with nasopharyngeal carcinoma who had received kilovoltage cone-beam computed tomography（KV-CBCT） and treated with IMRT were selected. The acquired images of KV-CBCT were compared to establish CT images with calculated setup errors of X-axis, Y-axis and Z-axis. Results：All the patients received the 168 KV-CBCT scans. The overall setup errors were below-0.15 ±1.43 mm in X-axis, 0.20 ±1.58 mm in Y-axis and-0.21±1.65 mm in Z-axis; The margins required for CTV-PTV were calculated 3.1 mm, 3.3 mm and 3.4 mm, respectively,according to the Van Herk formula. Conclusion： The application of KV-CBCT imaging system on the margin of CTV-PTV can measure and reduce the setup errors by correcting online.

关 键 词：鼻咽癌 KV-CBCT 调强放射治疗 摆位误差 

分 类 号：R739.6[医药卫生—肿瘤]