Schmidt E L, Rittler J, Steurer R
Abteilung Medizinische Physik am Westpfalz-Klinikum Kaiserslautern.
Strahlenther Onkol. 1999 Jan;175(1):39-41. doi: 10.1007/BF02743460.
One of the important prerequisites for using a virtual wedge is the availability of an appropriate method for quality assurance. A simple method to determine wedge angles has been developed.
A formula based on the exponential attenuation curve has been derived, that allows for the calculation of the wedge isodose angles based on 2 measurement points perpendicular to the central ray. The linear attenuation coefficient is the only variable that must be known for the field size under consideration.
Using the algorithm introduced, the wedge angle isodoses can be measured with a high degree of accuracy. The deviation of the wedge angle compared to the measurements done according to DIN 6847-4 is less than 1 degree.
The described procedure is a simple method of performing routine quality assurance for the virtual wedge.
使用虚拟楔形板的重要前提条件之一是要有合适的质量保证方法。现已开发出一种确定楔形角的简单方法。
已推导基于指数衰减曲线的公式，该公式允许根据垂直于中心射线的两个测量点计算楔形等剂量角。线性衰减系数是在所考虑的射野大小下唯一必须已知的变量。
使用所引入的算法，楔形角等剂量可高精度测量。与根据DIN 6847-4进行的测量相比，楔形角偏差小于1度。
所描述的程序是对虚拟楔形板进行常规质量保证的简单方法。
