螺旋断层调强放射治疗床沉降规律的测量和计算公式的拟合  

The measurement of decline rule of tomo therapy couch and fitting of the calculation formula

作　　者：孙显松 周兵 张宇[1] 杨志伟[1] 汪之群 于浪[1] 胡克[1] 张福泉[1] 邱杰[1] SUN Xiansong;ZHOU Bing;ZHANG Yu(Department of Radiotherapy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China)

机构地区：[1]中国医学科学院北京协和医学院北京协和医院放疗科

出　　处：《中国医学装备》2019年第6期37-41,共5页China Medical Equipment

摘　　要：目的:通过对螺旋断层调强放射治疗(TomoTherapy)治疗床沉降规律测量结果的分析,拟合计算公式,以指导靶区margin的外放以及图像引导扫描范围的选择。方法:从TomoTherapy治疗床床头敏感电子元件标记线开始,将治疗床划分成不同的压载区,设计26组系列压载方案,自床头标记线开始每隔10cm为1个沉降测量点,在机器等中心处测量治疗床的沉降值;根据测量结果拟合治疗床沉降值计算公式,并验证计算结果的准确性。结果:经过测量数据拟合与优化选择,得出治疗床等中心点沉降值y(mm)与治疗床等中心点前段承重x(kg)的关系公式为:y=-0.0781x-0.5557(r2=0.89)。结论:等中心处治疗床的沉降值与治疗床等中心前的承重呈良好的线性关系,拟合的线性函数可以很好的反应治疗床的沉降情况。针对人体体重分布特点,实测与计算值均反应胸腔及上腹部经过等中心点时床沉降变化的速度较快,对长靶区的治疗需要考虑治疗床沉降的影响。Objective: To fitting calculation formula through analyzed the measurement results of the decline rule of TomoTherapy treatment couch so as to guide the placement of margin of target region and the selection of the scope of MVCT scan. Methods: The couch was divided into different ballast areas which starting point was the label line of sensitive electronic component of the head of TomoTherapy couch, and series of ballast plan of 26 groups were designed. From the label line of the head of couch, the interval of measurement point of decline was one point per 10 cm. And the decline value of couch was measured at the isocenter point of machine. According to the measurement results to fitting calculation formula of decline value of treatment couch and verify the accuracy of calculation results. Results: Through the fitting of measurement data and optimization selection, the relationship formula between the decline value [y(mm)] at the isocenter point of the couch and the load-bearing value [x(kg)] at forepart of the isocenter point of couch was: y=-0.0781x-0.5557,(R2=0.89). Conclusion: The results show there is a good linearity between the decline value of the isocenter point of couch and the load-bearing at forepart of the isocenter point of couch. The fitting linear function can commendably reflect the situation of decline of couch. Aimed at the characteristics of weight distribution of human body, both measured values and calculated values reflect the velocity of the change of decline of couch when thoracic cavity and midsection pass isocenter point is rapid. Therefore, when the long target region of patients is treated, the influence of decline of couch needs to be taken into consideration.

关 键 词：断层调强放射治疗 巨电压螺旋CT 治疗床 图像引导 

分 类 号：R197.39[医药卫生—卫生事业管理]