How many plans are needed in an IMRT multi-objective plan database?
How many plans are needed in an IMRT multi-objective plan database?
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DOI：
10.1088/0031-9155/53/11/002
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发表时间：
2008-06-07
影响因子：
3.5
通讯作者：
Bortfeld, Thomas
中科院分区：
文献类型：
--
作者：
Craft, David;Bortfeld, Thomas
在多目标放射治疗计划中，我们对维度为 2 至约 10 的帕累托曲面感兴趣（对于头颈病例，需要权衡的结构数量可能如此之大）。尚未得到解答的一个关键问题是：需要多少个计划才能充分表示高维帕累托曲面？在本文中，我们提出了一种回答这个问题的方法，并且表明所需的点数是适度的：75 个计划始终将误差控制在 5% 以内，并且在除一个之外的所有情况下，N + 1 个计划（其中 N 是目标数量）足以将误差控制在 < 15% 之内。我们引入客观相关矩阵和子束解决方案的主成分分析（PCA）作为理解这一点的两种方法。 PCA 揭示了帕累托数据库的可行小束解位于整个小束空间的狭窄、小维子区域中，这有助于解释为什么表征数据库所需的计划数量很少。
In multi-objective radiotherapy planning, we are interested in Pareto surfaces of dimensions 2 up to about 10 (for head and neck cases, the number of structures to trade off can be this large). A key question that has not been answered yet is: how many plans does it take to sufficiently represent a high-dimensional Pareto surface? In this paper, we present a method to answer this question, and we show that the number of points needed is modest: 75 plans always controlled the error to within 5%, and in all cases but one, N + 1 plans, where N is the number of objectives, was enough for < 15% error. We introduce objective correlation matrices and principal component analysis (PCA) of the beamlet solutions as two methods to understand this. PCA reveals that the feasible beamlet solutions of a Pareto database lie in a narrow, small dimensional subregion of the full beamlet space, which helps explain why the number of plans needed to characterize the database is small.