Jones D, Andre P, Washington J T, Hafermann M D
Northwest Medical Physics Center, Lynnwood, WA 98036-7306.
Br J Radiol. 1990 Jan;63(745):59-64. doi: 10.1259/0007-1285-63-745-59.
A simple approach to the calculation of dose in cone-collimated electron fields is presented. The method accounts for variations in lateral scatter with field size using a Clarkson Integration. The reduction in output by an irregularly shaped aperture is evaluated based on measurements of the output at various distances from the aperture in a field 2.5 cm in diameter. The first 14 months of clinical use were analysed and it is shown that in 42 out of 600 calculations, the cutout factor was less than 0.95 and that in 77% of these, the calculation method was accurate to +/- 3%.
本文提出了一种计算锥形准直电子束剂量的简单方法。该方法使用克拉克森积分考虑了侧向散射随射野大小的变化。基于在直径为2.5 cm的射野中距孔径不同距离处的输出测量值，评估不规则形状孔径导致的输出减少。分析了临床使用的前14个月，结果表明，在600次计算中的42次中，遮挡因子小于0.95，其中77%的计算方法精确到±3%。
