摘要
目的分析脑转移患者立体定向放疗ExacTrac X线图像,计算分次间和分次内摆位误差及残余误差,分析进行逐弧位置验证的必要性。方法通过对过去2年在本中心采用头部立体定向放疗的脑转移瘤病例的回顾性分析,配准其数字重建图像和ExacTrac正交kV级验证图像,计算患者3个方向的平移误差和旋转误差。数据包含分次间摆位误差、分次内摆位误差和残余误差。结果75例116个病灶进行了337次头部立体定向放疗。分次间、分次内平移摆位误差分别为左右方向x(0.93±0.86)、(0.15±0.59)mm,头脚方向y(1.83±1.27)、(0.25±0.73)mm,腹背方向z(0.96±0.80)、(0.14±0.56)mm;分次间、分次内旋转摆位误差分别为矢状面Rx(0.65°±0.62°)、(0.19°±0.40°),横断面Ry(0.97°±0.94°)、(0.13°±0.25°),冠状面Rz(0.92°±0.71°)、(0.10°±0.29°)。残余平移误差左右、头脚、腹背方向分别为(0.06±0.23)、(0.08±0.24)、(0.08±0.22)mm;残余旋转误差矢状面、横断面、冠状面分别为(0.12°±0.27°)、(0.09°±0.18°)、(0.06°±0.19°)。337次分次间摆位误差99.1%超过误差阈值(0.7mm,0.7°)需要至少校正1次;1006组分次内摆位误差33.6%在治疗床转到位验证无需误差校正,66.4%需要校正至少1次。结论头部立体定向放疗患者要重视分次间摆位误差和分次内摆位误差,进行逐弧体位验证是非常必要的。
Objective To evaluate the necessity of arc by arc setup verification in patients with brain metastases receiving stereotactic radiotherapy (SRT) by analyzing the inter-and intra-fraction setup errors and residual errors collected from the ExacTrac X-ray portal image.Methods Clinical data of brain metastases patients treated with SRT in the previous two years were retrospectively analyzed.The ExacTrac X-ray setup images were collected after the normal setup procedure.Setup errors were calculated by registering the cranial bony structures of the ExacTrac X-ray setup images to that of the digitally reconstructed setup images.The inter-and intra-fraction setup errors and residual errors were statistically analyzed.Results Seventy-five patients from 116 lesions received 337 cycles of SRT of the head.The inter-and intra-fraction translational setup errors in the x,y and z directions were (0.93±0.86) mm and (0.15±0.59) mm;(1.83±1.27) mm and (0.25±0.73) mm;(0.96±0.80) mm and (0.14±0.56) mm,respectively.The inter-and intra-fraction rotational setup errors in the x,y,z directions were (0.65°±0.62°) and (0.19°±0.40°);(0.97°±0.94°) and (0.13°±0.25°);(0.92°±0.71°) and (0.10°±0.29°),respectively.The residual translational setup errors in the x,y,z directions were (0.06±0.23) mm,(0.08±0.24) mm and (0.08±0.22) mm,and (0.12°±0.27°),(0.09°±0.18°) and (0.06°±0.19°) for the residual rotational setup errors,respectively.For a reference setup error threshold of 0.7 mm/0.7°,99.1% of the SRT exceeded the threshold and required setup correction.For 1 006 non-coplanar arcs,rotating the treatment couch from 0° to the treatment angle made 66.4% of arcs exceed the threshold and require at least once setup correction.Conclusions During SRT for brain metastasis,the inter-and intra-fraction setup errors should be emphasized.It is necessary to perform arc by arc setup error verification.
作者
张彦新
符贵山
徐英杰
陈冰
方浩
刘博飞
刘清峰
肖建平
戴建荣
Zhang Yanxin;Fu Guishan;Xu Yingjie;Chen Bing;Fang Hao;Liu Bofei;Liu Qingfeng;Xiao Jianping;Dai Jianrong(Department of Radiation Oncology,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital,Chinese Academy of Medical Sciences ( CAMS ) and Peking Union Medical College (PUMC),Beijing 100021,China)
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2019年第6期448-451,共4页
Chinese Journal of Radiation Oncology
基金
中国癌症基金会北京希望马拉松专项基金(LC2015B02)
国家重点研发计划项目(2016YFC0904600)
中国医学科学院医学科学创新基金(CIFMS,2016-I2M-1-001).
