Bloch P, Wallace R
Med Phys. 1979 Mar-Apr;6(2):149-52. doi: 10.1118/1.594527.
The time required for accurate computer dose distributions is of major concern in radiation therapy. Isodose distributions were obtained by calculating the primary and scatter radiation reaching a point. A description of the primary dose distribution, especially at the edge of the beam, requires the calculation of the dose on a finely spaced grid. However, the scatter dose distributions can be described on a much coarser grid. The primary and scatter dose distribution calculations were separated into two computer subroutines which permitted choosing the appropriate grid spacing for each dose component. A more rational partition of the computing time for the primary and scatter dose was obtained. In addition, the separation of the calculation of the scatter dose from the total dose allows one to examine the calculated scatter dose distribution as the radial and angular increments used in the Clarkson-Cunningham summation are varied. Accurate scatter dose distributions were generated with a tenfold time reduction by optimization of grid spacing and radial and angular increments.
在放射治疗中，准确计算计算机剂量分布所需的时间是一个主要问题。通过计算到达某一点的原发射线和散射线来获得等剂量分布。描述原发射线剂量分布，尤其是在射束边缘处，需要在精细间隔的网格上计算剂量。然而，散射线剂量分布可以在粗得多的网格上进行描述。原发射线和散射线剂量分布的计算被分成两个计算机子程序，这允许为每个剂量分量选择合适的网格间距。从而更合理地分配了原发射线和散射线剂量的计算时间。此外，将散射线剂量的计算与总剂量的计算分开，使得当克拉克森 - 坎宁安求和中使用的径向和角度增量变化时，可以检查计算出的散射线剂量分布。通过优化网格间距以及径向和角度增量，在时间减少到十分之一的情况下生成了准确的散射线剂量分布。
