Cameron C
Division of Radiation Physics, Department of Radiation Oncology, Stanford Cancer Center, 875 Blake Wilbur Drive, Rm G-233, Stanford, CA 94305-5847, USA.
Phys Med Biol. 2005 Sep 21;50(18):4317-36. doi: 10.1088/0031-9155/50/18/006. Epub 2005 Sep 7.
Sweeping-window arc therapy (SWAT) is a variation of intensity-modulated radiation therapy (IMRT) with direct aperture optimization (DAO) that is initialized with a leaf sequence of sweeping windows that move back and forth periodically across the target as the gantry rotates. This initial sequence induces modulation in the dose and is assumed to be near enough to a minimum to allow successful optimization, done with simulated annealing, without requiring excessive leaf speeds. Optimal beam weights are calculated analytically, with easy extension to allow for variable beam weights. In this paper SWAT is tested on a phantom model and clinical prostate case. For the phantom, constant and variable beam weights are used. Although further work (in particular, improving the dose model) is required, the results show SWAT to be a feasible approach to generating deliverable dynamic arc treatments that are optimized.
扫描窗口弧形治疗（SWAT）是调强放射治疗（IMRT）的一种变体，采用直接孔径优化（DAO），它通过扫描窗口的叶片序列初始化，当机架旋转时，扫描窗口在靶区上来回周期性移动。这个初始序列会引起剂量调制，并且假定其足够接近最小值，以便在不要求过高叶片速度的情况下，通过模拟退火成功进行优化。通过解析计算最优射束权重，并且易于扩展以允许可变射束权重。在本文中，对体模模型和临床前列腺病例进行了SWAT测试。对于体模，使用了恒定和可变射束权重。尽管还需要进一步的工作（特别是改进剂量模型），但结果表明SWAT是生成可交付的优化动态弧形治疗的一种可行方法。
