Predicting the Influence of Microvascular Structure On Tumor Response to Radiotherapy
Predicting the Influence of Microvascular Structure On Tumor Response to Radiotherapy
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DOI：
10.1109/tbme.2016.2606563
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发表时间：
2017-03-01
影响因子：
4.6
通讯作者：
Byrne, Helen M.
中科院分区：
文献类型：
--
作者：
Grogan, James A.;Markelc, Bostjan;Byrne, Helen M.
目的：本研究的目的是探讨肿瘤对放射治疗（RT）反应的理论预测如何依赖于微血管网络的形态和空间表示。研究方法：一个混合多尺度模型，它耦合了一个细胞自动机模型的肿瘤生长与从血管的氧运输模型，用于预测一个星期的模拟RT后细胞的存活分数。人工和生物衍生的三维（3-D）血管网络以及血管化肿瘤被认为和预测相比，2-D的描述。结果如下：对于文献导出的值的细胞耗氧率有很小的差异时，预测的可行分数的生物或人工血管网络的3-D网络表示。不同的2-D表示被示出为相对于3-D情况过高或过低估计可行分数，基于逐点描述的预测被示出为对血管网络形态具有更大的敏感性。结论：当采用3-D表示时，预测的RT响应对微血管网络的形态相对不敏感，然而，在某些2-D表示中灵敏度更高。重要性：通过使用真实的3D血管网络几何形状，该研究表明，空间均匀氧气分布的真实的和人工网络描述和假设会导致相对较小组织体积中类似的RT响应预测。这表明，需要更详细地描述微血管中的氧转运，或者在众所周知的线性二次RT响应模型中使用的氧增强比对微血管结构相对不敏感。
Objective: The purpose of this study is to investigate how theoretical predictions of tumor response to radiotherapy (RT) depend on the morphology and spatial representation of the microvascular network. Methods: A hybrid multiscale model, which couples a cellular automaton model of tumor growth with a model for oxygen transport from blood vessels, is used to predict the viable fraction of cells following one week of simulated RT. Both artificial and biologically derived three-dimensional (3-D) vessel networks of well vascularized tumors are considered and predictions compared with 2-D descriptions. Results: For literature-derived values of the cellular oxygen consumption rate there is little difference in predicted viable fraction when 3-D network representations of biological or artificial vessel networks are employed. Different 2-D representations are shown to either over-or under-estimate viable fractions relative to the 3-D cases, with predictions based on point-wise descriptions shown to have greater sensitivity to vessel network morphology. Conclusion: The predicted RT response is relatively insensitive to the morphology of the microvessel network when 3-D representations are adopted, however, sensitivity is greater in certain 2-D representations. Significance: By using realistic 3-D vessel network geometries this study shows that real and artificial network descriptions and assumptions of spatially uniform oxygen distributions lead to similar RT response predictions in relatively small tissue volumes. This suggests that either a more detailed description of oxygen transport in the microvasculature is required or that the oxygen enhancement ratio used in the well known linear-quadratic RT response model is relatively insensitive to microvascular structure.