MM50加速器一维扫描调强的研究

Study on the One Dimension Scanning IMRT of MM50 Microtron

目的:初步探讨MM50一维电磁扫描调强。方法:利用MM50独特的计算机扫描调制和聚焦系统,研究MM50六边形扫描模式和圆形扫描模式。通过改变扫描模式研究一维适形调强方面的特点,将50MVX射线和电子线的扫描楔形分布实测的离轴曲线与理论曲线做对比分析。结果:实测曲线与理论曲线吻合良好。50MVX射线的扫描楔形分布,在楔形方向上的最大误差为1%,在对称方向上的最大误差为3%。50MeV电子线的楔形分布,计算结果与测量结果的差别小于2%。讨论:说明用MM50扫描束可获得较好的调强效果。

Objective: To study the one dimension scanned modulation realized by M M50's magnetic scanning beam. Methods: By means of the special scanned magnet sy stem and the focus magnet system, we studied the characteristics of MM50's one dimension scanned modulation which are realized by the MM50's hexagon scan patt erns or cycles scan patterns, compared and analyzed the difference between the m easuring curves and the theoretic curve of off axis for scanned wedge field. Res ults: The measuring curves are good agreement with the theoretic curves for the 50 MV X-ray's. The difference is less than 1% in the flat direction. And in the modulation direction the difference is less than 3%. For the 50 MeV electron bea m's wedge-shaped distribution graph, the difference is less than 2%. Discussion: We can get good scanned modulation by means of the MM50 scanning beam.