基于锥形束CT下肺癌立体定向放疗摆位误差研究及剂量验证  

Positioning error and dose verification of stereotactic radiotherapy for lung cancer based on cone beam CT

作　　者：朱国雄 胡昊 ZHU Guoxiong;HU Hao(Radiotherapy Center,Hunan Academy of Traditional Chinese Medicine,Changsha,Hunan 410013,China;Department of Oncology,the Third Xiangya Hospital,Central South University,Changsha,Hunan 410006,China)

机构地区：[1]湖南省中医药研究院放疗中心,湖南长沙410013 [2]中南大学湘雅三医院肿瘤科,湖南长沙410006

出　　处：《中国医学工程》2024年第5期16-21,共6页China Medical Engineering

摘　　要：目的研究不同手臂固定方式对于肺癌立体定向放射治疗(SBRT)中患者体位误差的影响及剂量验证分析。方法选取2019年3月至2022年12月在中南大学附属湘雅三医院肿瘤科收治的34例肺部SBRT治疗患者,分别采用双手交叉握杆(对照组)和双手抱肘置于前额(观察组)的方式固定手臂进行体位固定。每例患者每次治疗时均采用锥形束计算机断层扫描(CBCT),将CBCT扫描图像与CT模拟定位时的图像进行自动匹配,并结合靶区和骨性标志进行调整,计算患者在X、Y、Z轴方向上的误差并进行分析研究,同时选取阈值标准为(2%,2 mm,10%)和(3%,3 mm,10%)的条件下分析比较ArcCHECK模体理论计算剂量和ArcCHECK模体实测剂量之间的差异。结果34例研究对象共得到510组CBCT影像。其中对照组患者和观察组患者每次治疗前体位误差分别为左右方向LAT(1.69±4.43)和(2.25±1.54),头脚方向LNG(1.88±1.39)和(2.40±1.61),腹背VRT(1.26±0.98)和(1.70±1.08)。对照组在X、Y、Z三个方向上的误差数值均小于观察组,差异均有统计学意义(P<0.05)。当阈值标准为(2%,2 mm,10%)时,两组SBRT计划的绝对通过率均大于95%;当阈值标准为(3%,3 mm,10%)时,两组SBRT计划的绝对通过率均大于90%,均满足临床治疗要求。结论在肺癌SBRT治疗中,两种手臂固定方式基于ArcCHECK模体验证的绝对剂量通过率均满足临床要求,但双手交叉握杆的手臂固定方式对于患者体位的重复性和精准性更好。【Objective】To study the impact of different arm fixation methods on patient position error and dose verification analysis in stereotactic body radiation therapy(SBRT)for lung cancer.【Methods】Thirty-four patients who were admitted to the Oncology Department of the Third Xiangya Hospital Affiliated to Central South University and underwent pulmonary SBRT from March 2019 to December 2022 were selected,and their arms were fixed by holding the rod with both hands crossed(Control group)and holding the elbows with both hands on the forehead(Observation group).Cone beam computed tomography(CBCT)was used for each patient's treatment.The CBCT scan image was automatically matched with the image during CT simulation positioning,and the target area and bony landmarks were adjusted.The patient's error in the X,Y,and Z axis directions was calculated and analyzed.At the same time,the threshold standards as(2%,2mm,10%)and(3%,3mm,10%)were selected to analyze and compare the ArcCHECK phantom.The difference between the theoretically calculated dose and the measured dose on the ArcCHECK phantom was analyzed.【Results】A total of 510 sets of CBCT images were obtained from 34 research subjects.The position errors of patients in Control group and Observation group before each treatment were respectively LAT(1.69±4.43 and 2.25±1.54)in the left and right directions,LNG(1.88±1.39 and 2.40±1.61)in the head and foot directions,and ventral and dorsal VRT(1.26±0.98 and 1.70±1.08).The error values of Control group in the three directions of X,Y,and Z were smaller than those of Observation group,and the differences were statistically significant(P<0.05).When the threshold standard is(2%,2mm,10%),the absolute pass rates of both groups of SBRT plans are greater than 95%;when the threshold standard is(3%,3mm,10%),the absolute pass rates of both groups of SBRT plans are all greater than 90%,meeting clinical treatment requirements.【Conclusion】In the SBRT treatment of lung cancer,the absolute dose pass rates of the two arm fixation

关 键 词：锥形束CT 立体定向放射治疗 摆位误差 剂量验证 

分 类 号：R734.2[医药卫生—肿瘤]