X刀系统等中心精度检测方法

A Method for Measuring the Isocentre Positional Accuracy of X Knife System

在Ｘ刀的治疗过程中，系统的机械等中心定位精度是一个关键性的技术参数。本文介绍一种测量Ｘ刀系统机械等中心定位精度的方法，即胶片同心圆法。该方法是利用放置在等中心处的、代替靶区的模拟球在胶片上的成像（直径为８ｍｍ的圆）和准直器视野在胶片上的成像（直径为３０ｍｍ的圆），通过测量这两个圆圆心之间的距离即为系统的等中心偏差。本文详细介绍了该测量方法，并运用该方法进行了实际测量。

The mechanical isocentre positional accuracy of the X Knife system is a very important technological parameter in the course of the X Knife therpy. In this paper, a film concentric circle method for measuring the mechanical isocentre positional accuracy is introduced.A simulation ball set at the isocentre of the X Knife mechanical positonal system, as a substitute for target, was imaged on a film (the simulation ball's image is a circle and its diameter is 8mm), and a collimator was imaged on the same film (the collimator's image is also a circle and its diameter is 30mm). The distance between these two circles' centres is the error of the isocentric system. This method has been used in our work.