摘要
目的:通过采用射波刀进行腰椎转移肿瘤的放射治疗,并且利用交叉视野脊柱追踪技术得出误差结果并进行分析,并对临床上靶区设计提供参考数据。方法:选择我科室2017年10月至2019年4月接受射波刀治疗的14例腰椎转移肿瘤患者,中位年龄63岁(46~83岁)。患者根据临床要求采用仰卧位、真空垫固定,十字中心激光定位。在治疗过程中应用交叉视野脊柱追踪技术对靶区位置进行校正,行立体定向放射治疗(stereotactic body radiation therapy,SBRT)3~5次。每隔90 s采集一次正交图像并与参考数字图像(digital reconstructedly radiograph,DRR)行自动配比后记录误差值。分析治疗过程中采样点的随机误差,根据van Herk等人提出的MPTV=2.5Σ+0.7σ公式进行计算临床靶区(clinical target volume,CTV)到计划靶区(planning target volume,PTV)的外扩边界范围。结果:通过治疗过程中采集到6个方向上共749组数据分析得出,三个线性方向体位误差(系统误差±随机误差):X轴的偏差为(0.37±0.27)mm,Y轴的偏差为(0.29±0.22)mm,Z轴的偏差为(0.34±0.27)mm;三个旋转方向体位误差(系统误差±随机误差):L-R偏差为(0.30±0.21)°、DOWN-UP偏差为(0.25±0.20)°和CCW-CW偏差为(0.39±0.26)°。以上结果得出三个线性方向X、Y、Z的外放边界分别为1.11 mm、0.88 mm、1.04 mm。结论:腰椎肿瘤使用射波刀交叉视野脊柱追踪进行的椎体追踪技术可为临床靶区外放提供可靠的依据。
Objective:To analyze the errors of the radiotherapy of the lumbar metastatic tumor with X sight spine tracking of Cyberknife and provide the references for clinical target design.Methods:Fourteen lumbar metastatic tumor patients undergoing Cyberknife treatment were chosen in my department from October 2017 to April 2019,whose median age was 63 years old(from 46 to 83 years old).The patients who keep supine position were fixed with vacuum pad using the laster positioning method according to the clinic requirements.During the treatment,they were corrected their position with X sight spine tracking system,and treated by stereotactic body radiation therapy(SBRT) for 3~5 times.Orthogonal images were collected once every 90 seconds and the errors were recorded after they were matched automatically with digital reconstructedly radiograph(DRR).The outer boundary range of from clinical target volume(CTV) to planning target volume(PTV) was caculated according to the formula MPTV=2.5Σ+0.7σ by van Herk.etc by analyzing the random errors of sampling points during the treatment.Results:The three linear posture errors(system error±random error) of X-axis,Y-axis and Z-axis were(0.37±0.27) mm,(0.29±0.22) mm and(0.34±0.27) mm and the three rotational posture errors(system error±random error) of L-R,DOWN-UP and CCW-CW were(0.30±0.21)°,(0.25±0.20)° and(0.39±0.26)°,which were analyzed by collecting 749 data from the six directions during the treatment.So target volumn margin of the three linear directions of X,Y and Z were 1.11 mm,0.88 mm and 1.04 mm.Conclusion:The errors of the radiotherapy of the lumbar metastatic tumor with X sight spine tracking system can provide clinical target margin with reliable basis.
作者
赵田地
庄洪卿
王巍
姜树坤
王俊杰
Zhao Tiandi;Zhuang Hongqing;Wang Wei;Jiang Shukun;Wang Junjie(Department of Radiation Oncology,Peking University Third Hospital,Beijing 100191,China)
出处
《现代肿瘤医学》
CAS
2019年第20期3695-3698,共4页
Journal of Modern Oncology
关键词
射波刀
腰椎转移肿瘤
体位误差
立体定向放射治疗
Cyberknife
lumbar metastatic tumor
posture errors
stereotactic body radiation therapy
