MVCT引导下螺旋断层调强放射治疗摆位误差及靶区边界外放分析  

Analysis of positioning errors and margin of target region of intensity modulated helical tomotherapy under guidance of MVCT

作　　者：李洪明[1] 于浪[1] 孙显松 王欣海[1] 胡克[1] 张福泉[1] 邱杰[1] 

机构地区：[1]中国医学科学院北京协和医院放疗科,北京100730

出　　处：《中国医学装备》2017年第7期55-58,共4页China Medical Equipment

摘　　要：目的:对高能X射线计算机体层摄影(MVCT)引导下采用螺旋断层调强放射治疗技术(Tomotherapy)治疗的患者进行摆位误差分析,探讨科室整体摆位水平,并为靶区安全边界外放(Margin)提供依据。方法:对采用Tomo Therapy进行调强放射治疗的192例患者,每次治疗前行MVCT扫描,将其图像与计划CT图像进行配比,记录进出(LNG)、左右(LAT)、升降(VRT)和旋转(ROLL)四维方向的误差,并按部位分组(头颈、胸腹和盆腔3个部位),计算单个患者整个疗程误差分布规律及全部患者的系统误差(Σ)和随机误差(σ)大小,利用Margin公式(M=2.5Σ+0.7(σ)得出各部位不同方向的Margin值。结果:192例患者共获得4416幅MVCT图像,得出各部位在LNG、LAT、VRT和ROLL方向的摆位误差分别为:头颈部(1.94±1.78)mm、(0.94±0.81)mm、(1.07±0.98)mm和(0.75±0.89)°;胸腹部(3.72±2.92)mm、(2.12±1.96)mm、(2.04±1.65)mm和(0.47±0.71)°;盆腔(3.68±2.52)mm、(1.36±1.20)mm、(1.83±1.41)mm和(0.47±0.51)°,整体摆位误差为:(3.172.96)mm、(1.401.42)mm、(1.581.40)mm和(0.580.74)°,各部位在LNG、LAT和VRT方向的Margin分别为:头颈部5 mm、2 mm和2 mm;胸腹部8 mm、7 mm和5mm;盆腔6 mm、4 mm和3 mm。结论:通过对MVCT引导下采用螺旋断层调强放射治疗患者的摆位误差数据分析,了解科室整体摆位水平,为各部位的Margin外放提供可靠依据,临床疗效及副反应尚待进一步研究。Objective： To analyze the position error of patient received intensity modulated helical tomotherapy under guidance of megavoltage computed tomography（MVCT） and discuss the whole position level of department. Besides, to provide references for safe margin of target region. Methods： 192 patients were treated by using intensity modulated helical tomotherapy. They were scanned by MVCT before every therapy was implemented and their scanned results were compared with planning CT. The errors of 4 directions including LNG, LAT, VRT and ROLL were recorded, and these data were divided into three groups（head and neck group, chest and abdomen group and pelvic group） as the different body parts. The error distribution law of whole treatment for every patient, the system error（Σ） and random error（σ） for all of patients were calculated. And then the Margin value of different direction of various body parts was obtained by using Margin formula（M=2.5Σ ＋0.7（σ））. Results： 4416 images were obtained from 192 patients, and the position error of different body parts on 4 directions（LNG, LAT, VRT and ROLL） were： head and neck（1.94±1.78 mm, 0.94±0.81 mm, 1.07±0.98 mm and 0.75±0.89 mm）, chest and abdomen（3.72±2.92 mm, 2.12±1.96 mm, 2.04±1.65 mm and 0.47±0.71 mm）, and pelvis（3.68±2.52 mm, 1.36±1.20 mm, 1.83±1.41 mm and 0.47±0.51mm）, respectively. The whole position errors were 3.172.96 mm, 1.401.42 mm, 1.581.40 mm and 0.580.74 mm. The Margin values of different body parts on LNG, LAT and VRT were： head and neck（5 mm, 2 mm and 2 mm）, chest and abdomen（8 mm, 7 mm and 5 mm） and pelvis（6 mm, 4 mm and 3 mm）, respectively. Conclusion： Through the data analysis about position errors of patients treated by using intensity modulated helical tomotherapy under the guidance of MVCT, the whole position situation of department is grasped and these relative data provide reliable reference for Margin of different body parts. And its clinical effects and adverse reaction nee

关 键 词：摆位误差 边界外放 螺旋断层放射治疗 影像引导放射治疗 医院直线加速器 

分 类 号：R814.42[医药卫生—影像医学与核医学]