用KV-CBCT对食管癌不同固定体位动态调强分次间摆位误差的研究  

Usage of KV-CBCT to Measure the Influence of Different Fixed Positions on the Setup Errors of Dynamic Intensity Modulation for Esophageal Cancer

作　　者：徐晓捷 张瑞英[1] 雷亚楠 侯鹏 李敬霞[1] XU Xiao-jie;ZHANG Rui-ying;LEI Ya-nan;HOU Peng;LI Jing-xia(The First Affiliated Hospital,and College of Clinical Medicine of Henan University of Science and Technology,Luoyang,China,471003)

机构地区：[1]河南科技大学临床医学院,河南科技大学第一附属医院肿瘤放疗科,洛阳471003

出　　处：《食管疾病》2021年第1期39-42,共4页Journal of Esophageal Diseases

摘　　要：目的用千伏级锥形束CT(KV-CBCT)测量食管癌动态调强(DMLC)不同固定体位的摆位误差,以确定不同固定体位临床靶区(CTV)的外扩距离,减少正常组织的照射量。方法选择2019年5月至2020年1月27例食管癌患者,每周3次KV-CBCT扫描获得405组摆位误差数据,并对左右(x轴)、上下(y轴)、前后(z轴)的摆位误差行成组t检验,调查固定方式对CTV外扩计划靶区(PTV)的距离的影响。结果体膜固定为A组,头颈肩膜固定为B组。摆位绝对误差x轴和z轴A组小于B组,分别为(1.911±1.641)mm、(2.738±2.229)mm(P<0.05)和(1.342±1.072)mm、(1.977±1.348)mm(P<0.05);而y轴A组大于B组,分别为(4.386±4.206)mm、(2.728±2.743)mm(P<0.05)。两组食管癌患者接受动态调强时PTV与CTV之间的距离分别为x(2.613,6.080)mm、y(5.775,5.882)mm、z(2.814,3.467)mm,且A组和B组在x、y和z方向上均有显著差异。结论两种体位固定方式各有优劣,且误差均在可控范围内。可根据实际情况外扩CTV到PTV的距离。Objective To measure the different fixed positions on the setup errors of dynamic intensity modulation(DMLC)for thoracic esophageal carcinoma with kilo-voltage cone-beam CT(KV-CBCT),and to determine the outer expansion distance of the clinical target area(CTV)of different fixed positions to reduce the radiation dose of normal tissue.Methods Twenty-seven patients with esophageal cancer were selected from May 2019 to January 2020.405 sets of positioning error data were obtained from the patients who performed KV-CBCT scans three times a week,the group t tests on the positioning errors of left and right(x axis),up and down(y axis),and back and forth(z axis),were performed.Effects of different fixed methods on the distance of CTV external expansion PTV were studied.Results There were group A and group B.The absolute errors of the x-axis and z-axis positioning of group A were(1.911±1.641)mm and(1.342±1.072)mm,which were less than those in group B(2.738±2.229)mm(P<0.05)and(1.977±1.348)mm(P<0.05),respectively.The absolute errors of the y-axis of group B is less than those of group A(P<0.05),which were(2.728±2.743)mm and(4.386±4.206)mm.The distances between PTV and CTV in two groups were x(2.613,6.080)mm,y(5.775,5.882)mm,and z(2.814,3.467)mm,significant differences between group A and group B.Conclusion The two posture fixation methods have their own advantages and disadvantages,and the errors are within the controllable range.This study provides a reference basis for expanding the distance from CTV to PTV.

关 键 词：食管癌 K-CBCT 体位 摆位误差 

分 类 号：R735.1[医药卫生—肿瘤]