多平面重组图像引导定位参考点标记法在宫颈癌放射治疗定位中的应用  

Application of reference point labeling guided and localized by multiplanar reformation image in the localization of cervical cancer radiotherapy

作　　者：成肇杰 刘光明 韦婷[1] 梁卫学[1] 苏婷[1] 王占宇[1] CHENG Zhaojie;LIU Guangming;WEI Ting;LIANG Weixue;SU Ting;WANG Zhanyu(Department of Oncology,the Fourth Affiliated Hospital of Guangxi Medical University/Liuzhou Workers Hospital,Guangxi Liuzhou 545005,China)

机构地区：[1]广西医科大学第四附属医院/柳州市工人医院肿瘤科,广西柳州545005

出　　处：《现代肿瘤医学》2023年第19期3634-3639,共6页Journal of Modern Oncology

基　　金：广西壮族自治区卫生健康委员会科研课题(编号:Z-B20221401,Z20200503);广西重点研发计划(编号:桂科AB22035026);广西柳州市科技重大专项(编号:2019AF10601)。

摘　　要：目的:探讨多平面重组(multiplanar reformation,MPR)图像引导定位参考点标记法在宫颈癌放射治疗定位中的应用价值。方法:选取2022年05月至12月在我院肿瘤放射治疗中心进行容积旋转调强放射治疗(volumetric-modulated arc therapy,VMAT)的40例宫颈癌患者,采用随机数表法将其分为观察组和对照组,每组20例。观察组使用MPR图像引导定位参考点标记法进行定位;对照组使用常规参考点标记法进行定位。物理师进行VMAT放疗计划设计时,根据国际辐射单位及测量委员会(international commission on radiation units and measurements,ICRU)参考点的选择原则,选出靶区剂量归一的规定点并作为治疗中心点,比较两组患者治疗中心点与定位参考点位移的例数,并用位移率(%)进行描述。所有患者首次治疗及以后每周均进行一次锥形束CT(CBCT)扫描位置验证(共5次),分别采集两组患者分次间的左右X、头脚Y、腹背Z方向上的摆位误差数据及复位完成的时间,采用独立样本t检验,P<0.05为差异有统计学意义。计划靶区外放边界(M_(PTV))公式:M_(PTV)=2.5∑+0.7σ计算不同定位方式下的靶区外扩边界。结果:观察组中定位参考点与治疗中心点在三维方向上产生位移例数均为0例,而对照组在Y方向、Z方向产生位移例数分别是11例和19例,位移率分别55%和95%。观察组的平均摆位误差分别为X(-0.16±1.99)mm、Y(1.04±4.13)mm、Z(0.77±2.30)mm;对照组的平均摆位误差分别为X(0.18±2.59)mm、Y(-2.09±5.02)mm、Z(1.44±2.39)mm。两组Y、Z方向上的摆位误差有统计学意义(P<0.05)。观察组复位平均时间(9.76±2.35)min,对照组复位平均时间(13.25±3.66)min,观察组较对照组复位效率更高。观察组靶区外扩边界(M_(PTV))分别为3.82 mm、7.28 mm、4.55 mm,较对照组减少了18.20%、22.06%、6.38%。结论:在宫颈癌放射治疗定位中使用多平面重组图像引导定位参考点标记法可实现定位参考点与�Objective:To investigate the application value of reference point labeling guided and localized by multiplanar reformation(MPR)image in the localization of cervical cancer radiotherapy.Methods:A total of 40 patients with cervical cancer who underwent volumetric modulated arc therapy(VMAT)in the tumor radiotherapy center of our hospital from May to December 2022 were selected and divided into observation group and control group by random number table method,with 20 cases in each group.The patients in the observation group used the reference point labeling guided and localized by MPR image to locate,and those in the control group used conventional reference point labeling to locate.In the design of VMAT radiotherapy plan,according to the selection principle of ICRU reference point,the prescribed point of dose normalization in the target area was selected as the central point of treatment.The number of patients in which the displacement between the treatment center point and the positioning reference point was compared between the two groups,and the displacement rate(%)was described.Conical beam CT(CBCT)scanning position verification was performed at the first treatment and once a week after the first treatment for all patients(a total of 5 times).The positioning error data of left and right X,head and foot Y,abdominal and dorsal Z directions between the two groups and the time to complete reset were collected respectively,and independent sample t test was used.P<0.05 was considered statistically significant.The formula to calculate margin planning target volume(M PTV),M_(PTV)=2.5∑+0.7σ,was used to calculate the external boundary of the target under different positioning methods.Results:In the observation group,0 case of positioning reference point and treatment center point had displacement in the three-dimensional direction,while in the control group,11 cases and 19 cases had displacement in the Y direction and Z direction,with displacement rates of 55%and 95%,respectively.The average positioning errors of the

关 键 词：宫颈癌 摆位误差 放疗定位 参考点标记法 

分 类 号：R737.33[医药卫生—肿瘤]