摘要
目的:探讨鼻咽癌放射治疗CT模拟定位点和放射治疗点同中心、不需要换算三维坐标的可行性,为鼻咽癌放射治疗的定位提供指导。方法:回顾性选取40例2019年7月至12月我院放疗科接受调强放射治疗的初治鼻咽癌患者为研究对象,均采用调强适形放射治疗(intensity modulated radiotherapy,IMRT)。根据定位点和治疗点是否同中心将满足入组条件的患者分为A组(治疗点和定位点同中心)和B组(治疗点和定位点不同中心)。每名患者在第一次治疗及之后每周治疗前均行一次锥束计算机断层扫描(cone-beam computed tomography,CBCT)。将CBCT图像与计划CT图像进行匹配,采集摆位误差数据。观察两组不同定位点选取方法下X(左右)、Y(前后)、Z(上下)三维方向的摆位误差,并使用Van-Herk扩边公式求出X(左右)、Y(前后)、Z(上下)的PTV外扩边界值。采用两样本均数比较的t检验、χ^(2)检验进行统计分析、用例数(n)和百分比(%)进行描述。以P<0.05为差异有统计学意义。结果:A组3个方向的平均摆位误差分别为X轴(0.350±1.029)mm、Y轴(0.660土1.545)mm、Z轴(0.910±1.288)mm。B组3个方向的平均摆位误差分别为X轴(0.160±1.269)mm、Y轴(1.440±1.604)mm、Z轴(1.590±1.393)mm。两组在Y(前后)、Z(上下)轴的摆位误差差异均有统计学意义(P<0.05)。A、B两组鼻咽癌患者X方向的群体MPTV为2.65 mm和3.28 mm,Y方向的群体MPTV为3.77 mm和3.92 mm,Z方向的群体MPTV为3.01 mm和3.39 mm。结论:鼻咽癌放射治疗CT模拟定位点和放射治疗点同中心,不换算三维坐标是可行的,能满足临床上对于摆位误差和外扩边界的要求。
Objective:To explore the feasibility of keeping the same CT simulation location point and radiotherapy point without converting three-dimensional coordinates for radiotherapy of nasopharyngeal carcinoma,and to provide guidance for radiotherapy positioning of nasopharyngeal carcinoma.Methods:A retrospective study was conducted on 40 newly treated patients with nasopharyngeal carcinoma who received IMRT in the department of radiotherapy of our hospital from July to December 2019.All patients were treated with IMRT.Patients meeting the inclusion criteria were divided into group A(treatment points were consistent with the registration points)and group B(treatment points were inconsistent with the registration points)according to whether the CT registration points and treatment points were consistent.Each patient underwent cone-beam computed tomography(CBCT)weekly prior to treatment.The CBCT images were matched with planned CT images,and the setup errors data were collected.The setup errors of X(left and right),Y(front and rear),Z(upper and lower)in three dimensional directions were observed under two groups of different selection methods of anchor points,and the Van Herk edge expansion formula was used to calculate the PTV outward expansion boundary values of X(left and right),Y(front and rear),Z(upper and lower).The t-test andχ^(2) test were used for statistical analysis,and the number of cases(n)and percentage(%)were used for description.P<0.05 was considered statistically significant.Results:The average setup errors of group A in three directions were(0.350±1.029)mm in X axis,(0.660±1.545)mm in Y axis,and(0.910±1.288)mm in Z axis,respectively.The average setup errors of group B in three directions were(0.160±1.269)mm in X axis,(1.440±1.604)mm in Y axis,and(1.590±1.393)mm in Z axis,respectively.There were statistically significant differences in Y(front and rear)and Z(upper and lower)axis setup errors between the two groups(P<0.05).In group A and B,the MPTV in the X direction was 2.65 mm and 3.28 mm,the MPTV in the Y direction was 3.77 mm and 3.92 mm,and the MPTV in the Z direction was 3.01 mm and 3.39 mm.Conclusion:It is feasible to not convert three-dimensional coordinates between simulated locus and radiotherapy points for radiotherapy of nasopharyngeal carcinoma,which can meet the clinical requirements of setup error and expanding boundary.
作者
钟强
覃文
王仁生
ZHONG Qiang;QIN Wen;WANG Rensheng(Department of Radiotherapy,Wuzhou Red Cross Hospital,Guangxi Wuzhou 543002,China;Department of Radiotherapy,the FirstAffiliated Hospital of Guangxi Medical University,Guangxi Nanning 530021,China)
出处
《现代肿瘤医学》
CAS
北大核心
2022年第16期2999-3004,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:Z20190380)
广西壮族自治区梧州市科技计划项目(编号:201902169)。
