摘要
目的基于螺旋断层放射治疗同源兆伏级(Megavoltage Computed Tomography,MVCT)图像引导系统,研究乳腺癌螺旋断层放疗使用一体化托架结合热塑膜与乳腺托架两种固定技术的摆位精度差异及临床适用性。方法选取2019年8月至2020年3月在湖南省肿瘤医院进行螺旋断层放射治疗的30例乳腺癌患者,分为热塑膜组(15例)和托架组(15例),热塑膜组采用一体化托架结合热塑膜固定技术,托架组采用乳腺托架固定技术。两组患者放疗摆位后采用螺旋断层放疗同源MVCT进行影像引导摆位误差验证,获得左右(x)、头脚(y)、腹背(z),旋转(R)方向摆位误差,记录两组摆位时间。对两组患者摆位误差先计算均值,再对均值分组进行方差分析和独立样本t体验,并计算CTV-计划靶体积(Planning Target Volume,PTV)靶区外扩间距值。结果热塑膜组与托架组的摆位误差分别为:x轴(2.03±0.92)mm和(2.87±0.84)mm;y轴(1.84±0.73)mm和(2.38±1.30)mm;z轴(2.08±0.73)mm和(3.33±1.61)mm;R旋转(0.30±0.19)°和(0.54±0.29)°。两组患者的摆位误差在x轴、z轴、R旋转轴三个方向有显著性差异;y轴无显著性差异。CTV-PTV靶区外扩边界值分别为2.88 mm和4.52 mm、2.99 mm和3.9 mm、2.69 mm和4.63 mm;单次摆位时间分别为(4.2±2.1)min和(6.3±3.3)min。结论乳腺癌螺旋断层放射治疗中使用一体化托架结合热塑膜固定技术比乳腺托架固定技术摆位误差小,可提高治疗精度和摆位效率,有更好的临床适用性,值得推广。
Objective To study the difference of set-up errors and clinical applicability of two immobilization techniques including integrated bracket combined with thermoplastic membrane and breast bracket for breast cancer patients in radiotherapy based on megavoltage computed tomography(MVCT)image guidance system.Methods Thirty patients with breast cancer who underwent helical tomotherapy from August 2019 to March 2020 in Hunan cancer hospital were included in this study and randomly divided into thermoplastic membrane group(15 cases)and breast bracket group(15 cases).Patients in thermoplastic membrane group were immobilized with integrated bracket combined with thermoplastic membrane,while the breast bracket group was fixed with breast bracket.After positioning,spiral homologous MVCT image guidance system was used to verify the image-guided set-up errors,obtain the set-up errors in left-right(x),superior-inferior(y),anterior-posterior(z),rotation(R)directions,and record the positioning time of two groups.The mean value of the set-up errors of two groups was calculated,and then the mean was grouped for analysis of variance and independent samples t-test.The outspread value of inter-fractional set up error of the planning target volume(PTV)was calculated.Results The errors of the thermoplastic membrane group and the breast bracket group in the direction of x,y,z,R were as follows:(2.03±0.92)mm and(2.87±0.84)mm;(1.84±0.73)mm and(2.38±1.30)mm;(2.08±0.73)mm and(3.33±1.61)mm;(0.30±0.19)°and(0.54±0.29)°.There were significant differences between the two groups in the three directions of x,z and R;there was no significant difference in y-axis.The extension values of inter-fractional set-up error of CTV to PTV were 2.88 and 4.52 mm,2.99 and 3.9 mm,2.69 and 4.63 mm respectively.The time of single positioning was(4.2±2.1)min and(6.3±3.3)min respectively.Conclusion In the helical tomotherapy for breast cancer,the positioning error of the integrated bracket combined with thermoplastic membrane immobilization technique is smaller than that of the breast bracket immobilization technique,which can improve the treatment accuracy and positioning efficiency,and has better clinical applicability and is worthy of popularization.
作者
张利
李忠伟
吴迪
杨锫
ZHANG Li;LI Zhongwei;WU Di;YANG Pei(Department of Radiological Physics and Technology,Hunan Cancer Hospital,Changsha Hunan 410013,China;Department of Third Head and Neck Radiotherapy,Hunan Cancer Hospital,Changsha Hunan 410013,China)
出处
《中国医疗设备》
2021年第11期55-58,66,共5页
China Medical Devices
基金
湖南省科学技术厅科技创新计划(2018SK50902)
湖南省保健专项资金科研课题(A2018-03)。