摘要
目的:采用千伏级锥形束CBCT(Kilovolt cone-beam computed tomography)测量和分析肺癌调强放疗摆位误差,并依此分析CTV外扩至PTV的边界大小,为我科放疗计划的设计提供一定的理论依据。方法:对2019年1-8月在我院全程进行图像引导放射治疗的60例肺癌患者的摆位误差进行测量。体位固定采用一体板和热塑体膜。每例患者在第1周的每一次以及之后的每周放射治疗前利用锥形束CT扫描;将获取的CBCT影像与治疗计划CT进行比较,记录并分析治疗过程中的摆位误差,以此为依据计算CTV-PTV外放边界大小。结果:60例肺癌共采集413次摆位数据;经测量得到X左右方向误差为(1.662 32±1.422 25)mm;Y头脚方向误差为(2.127 05±1.366 56)mm;Z背腹方向误差为(2.119 32±1.580 24)mm;经公式计算,得到我科肺癌外扩CTV理论边界X左右、Y头脚、Z背腹各方向分别为1.88mm、5.66mm、2.71mm。结论:应用千伏级锥形束CBCT测量和分析肺癌治疗前的摆位误差的规律,并计算CTV外扩边界的大小,可以为我科外扩CTV边界提供理论依据,具有实际的临床意义。
Objective:To measure and analyze the set-up errors of intensity modulated radiotherapy for lung cancer and calculate the CTV referential safety margins of PTV by using Kilovolt cone-beam computed tomography(CBCT),which can providing a theoretical basis for the design of radiotherapy plan in our department.Methods:The set-up errors of 60 patients undergoing image-guided radiotherapy in our hospital from January to August in 2019 were examined in this study. An integral plate and thermoplastic membrane was used for immobilization.A cone beam CT scan was taken for each patient prior the first treatment and the latter per week;compared the obtained CBCT images and CT images of the treatment plan, we recorded the set-up errors and analyzed the CTV referential safety margins of PTV according to the ctv-ptv boundary formula. Results:Total of 413 images were obtained from 60 patients, and the setup errors of X, Y and Z were(1.662 32±1.422 25)mm,(2.127 05±1.366 56)mm and(2.119 32±1.580 24)mm,respectively;The margin of CTV of lung cancer in three directions(X,Y,Z) was 1.88 mm,5.66 mm and 2.71 mm respectively.Conclusion:It laid a practical clinical significance foundation for calculating our CTV margins by measuring and analyzing the set-up errors with using kilovolt cone-beam computed tomography.
作者
张骥
宰宇
唐甜
ZHANG Ji;ZAI Yu;TANG Tian(The Third Hospital of Central South University,Changsha City,Hu’nan Province 410013)
出处
《医学理论与实践》
2020年第11期1732-1734,1752,共4页
The Journal of Medical Theory and Practice
关键词
肺癌
调强放射治疗
摆位误差
外扩边界
Lung cancer
Intensity modulated radiotherapy
Set-up errors
Margin
