螺旋断层治疗超长靶区18例分段获取影像引导摆位误差分析  

An analysis of positioning errors of extraordinarily long distance target in helical tomotherapy

作　　者：王振立[1] 郑安平[1] 朱健[2] 王晓敏[1] 张耀文[1] 孙晓东[1] 王银亮[1] 王瑞立 WANG Zhen-li;ZHENG An-ping;ZHU Jian;SUN Xiao-dong;WANG Yin-liang;WANG Rui-li(Department of Radiation Oncology,Anyang Tumor Hospital,Anyang 455000,China;Department of Radiation Oncology Physic and Technology,Shangdong Cancer Hospital and Institute,Ji'nan 250117,China)

机构地区：[1]安阳市肿瘤医院放疗中心,河南安阳455000 [2]山东省肿瘤防治研究院放射物理技术科,山东济南250117

出　　处：《中华肿瘤防治杂志》2021年第5期344-349,共6页Chinese Journal of Cancer Prevention and Treatment

基　　金：国家自然科学基金(81671785,81530060);国家重点研发计划子课题(2016YFC0105106);山东省自然科学基金项目(ZR2016HQ09);山东第一医科大学学术提升计划项目(2020RC003);河南省医学科技攻关计划(LHGJ20191285);安阳市肿瘤医院中青年科研项目专项资金([2019]23);山东省泰山学者青年专家项目(tsqn201909140)。

摘　　要：目的探讨螺旋断层治疗(HT)在治疗超长靶区(头脚方向长度超过40cm)患者时分段获取兆伏级CT(MVCT)影像引导的必要性。方法选取2017-01-01-2019-12-31在安阳市肿瘤医院进行螺旋断层治疗的超长靶区患者18例,分为头体组(10例)和体部组(8例)。治疗前行分段MVCT扫描总计588次,每例患者获得的前后两段图像分别与定位CT图像进行配准,记录左右(x)、头脚(y)和腹背(z)方向的平移误差,计算CTV-PTV的外扩范围。采用SPSS19.0对符合正态分布的数据进行配对样本t检验,不符合正态分布的则采用Wilcoxon秩和非参数检验。结果摆位误差从头颈到胸腹有逐渐增大的趋势。其中头体组头部和体部摆位误差在y轴方向差异有统计学意义(P=0.008),体部组体上部和体下部在x方向和z方向差异有统计学意义(P=0.001;P<0.001)。在行图像引导前提下,头颈部推荐外扩为3.5~4.0mm,胸腹部为4.5~5.0mm。结论分段扫描可以最大程度减小摆位误差。超长靶区的摆位误差从低到高依次为头部、胸部和腹部,在CTV-PTV进行外扩时要注意这种变化。为了尽可能减小摆位误差,超长靶区患者每次治疗前应该行分段MVCT扫描。Objective To evaluate the need for section scanning for helical tomotherapy in the treatment of patients with super long distance target(target length exceeds 40 cm).Methods Eighteen patients with ultra-long distance target from2017 to 2019 was selected.They were divided into head-body group(10 patients)and body group(8 patients).A total of588 segmented MVCT scans were performed before treatment and the obtained two series of images of every patient were registered with the positioning KVCT images separately.The setup errors of left-right(x),craniocaudal(y),and anteroposterior(z)directions were recorded,and the external expansion range of CTV-PTV was calculated.SPSS 19.0 software was used for statistical analysis and discussed whether it was necessary to conduct segmented MVCT scanning for the ultra-long target area.Results The data showed that the positioning error gradually increased from the head and neck to the chest and abdomen;and there was a statistically significant difference in the Y-axis direction compared the head with the body in the head-body group(P=0.008),and a statistically significant difference in the x-direction and z-direction between the upper body and lower body in the body group(P=0.001;P<0.001).When performing image-guided radiotherapy,the recommended expansions were 3.5 to 4 mm for the head and neck and 4.5 to 5 mm for the chest and abdomen.Conclusions The positioning errors of the ultra-long target area are head,chest and abdomen from low to high which should be paid attention to during the outward expansion of CTV-PTV.In order to minimize the positioning error,patients with ultra-long target area should receive segmented MVCT scan before each treatment.

关 键 词：超长靶区 螺旋断层治疗 摆位误差 分段扫描 

分 类 号：R730.5[医药卫生—肿瘤]