摘要
采用一个模拟实例,用模拟动力学方法进行调强放疗的最优化计算,检验该最优化问题是否存在简并解。结果表明,在有剂量—体积约束的情况下,最优化计算有简并解,即这些解都给出了满足优化条件的剂量—体积直方图,但射束元强度分布不同。因此,可以在这些简并解中作进一步优化,挑选强度分布最平滑的解作为最后的最优解,这将有利于调强的实现。
Using the simulated dynamics algorithm for IMRT optimization, intensity profile optimizations for a simulated case have been performed by starting with different initial conditions. By the different initial conditions, the resultant DVHs for the PTV are the same and the DVHs for OARs satisfy given constraints, although the intensity profiles could be different. These results verify that there exist degenerated solutions for the optimization problem even with dose-volume constraints included. This feature of the optimization problem could be useful in selecting a plan that results satisfying dose distribution and also has smooth intensity profile.
出处
《中国医学物理学杂志》
CSCD
2004年第2期67-69,90,共4页
Chinese Journal of Medical Physics
基金
国家自然科学基金资助项目(10275045)
关键词
调强放射治疗(IMRT)
最优化
剂量-体积约束
简并态
intensity-modulated radiotherapy (IMRT)
optimization
dose-volume constraints
degenerate state
