旋转照射与X刀照射剂量分布的理论分析

THEORETICAL ANALYSIS OF DOSE DISTRUBUTION IN ROTATION AND X KNIFE TREATMENT

本文利用理想线束的概念分析旋转治疗及Ｘ刀剂量分布的规律。分析了受照射的时间对剂量分布的影响。这时任何线束的剂量分布关系相对于照射野的宽度基本相同。多平面旋转治疗的剂量分布随平面数增加剂量更集中于靶区，但是，在轴区的剂量分布不变。重叠区大小随平面数增加而迅速变大，不重叠区剂量随平面数增加而减少。

The rule of the dose distributiion about rotation and X knife treatment is anal ysed by the help of ideal beams.It is found that the irradiated time is a main factor to influence the dose distribution.The relation between the dose distributions and the widths of fields are always the same.the more rotation planes are used for treatment,the more dose concentrats in the target area,but in the axis area the dose distribution does not change.On the other hand,As the number of rotation planes increases,the overlap area also increases but the dose in the un overlap area decreases.