Dunscombe P, Ross C
Northeastern Ontario Regional Cancer Centre, Sudbury, Canada.
Med Phys. 1993 Nov-Dec;20(6):1705-7. doi: 10.1118/1.596957.
In a recent paper [Med. Phys. 19, 1441 (1992)] it was shown that the field size dependence of on-axis relative output from a linear accelerator can be well described by a model comprising two components. One component represents radiation emanating from a point source and the other represents radiation from a field size dependent distributed source. In this communication the application of the model is extended to off-axis situations and demonstrates that a good description of the dependence of off-axis output on collimator configuration can be obtained. Of particular clinical relevance in this regard is the beam profile of half blocked fields which are adequately reproduced. The model has also been applied to the study of profiles generated by simulated dynamic wedging.
在最近的一篇论文[《医学物理》19, 1441 (1992)]中表明，直线加速器轴上相对输出的射野大小依赖性可以由一个包含两个分量的模型很好地描述。一个分量表示从点源发出的辐射，另一个分量表示来自与射野大小相关的分布式源的辐射。在本通讯中，该模型的应用扩展到了离轴情况，并证明可以很好地描述离轴输出对准直器配置的依赖性。在这方面，特别具有临床相关性的是半阻挡射野的射束轮廓，其得到了充分再现。该模型还被应用于模拟动态楔形产生的轮廓的研究。
