School of Information Science and Engineering Zhejiang Sci-Tech University, Hangzhou,Zhejiang, China.
School of Information Science and Engineering Zhejiang Sci-Tech University, Hangzhou,Zhejiang, China; Department of Systems and Computer Engineering Carleton University,Ottawa,ON KIS 5B6, Canada.
Comput Methods Programs Biomed. 2022 Dec;227:107233. doi: 10.1016/j.cmpb.2022.107233. Epub 2022 Nov 11.
Modeling of glioma growth and evolution is of key importance for cancer diagnosis, predicting clinical progression and improving treatment outcomes of neurosurgery. However, existing models are unable to characterize spatial variations of the proliferation and infiltration of tumor cells, making it difficult to achieve accurate prediction of tumor growth.
In this paper, a new growth model of brain tumor using a reaction-diffusion equation on brain magnetic resonance images is proposed. Both the heterogeneity of brain tissue and the density of tumor cells are used to estimate the proliferation and diffusion coefficients of brain tumor cells. The diffusion coefficient that characterizes tumor diffusion and infiltration is calculated based on the ratio of tissues (white and gray matter), while the proliferation coefficient is evaluated using the spatial gradient of tumor cells. In addition, a parameter space is constructed using inverse distance weighted interpolation to describe the spatial distribution of proliferation coefficient.
The glioma growth predicted by the proposed model were tested by comparing with the real magnetic resonance images of the patients. Experiments and simulation results show that the proposed method achieves accurate modeling of glioma growth. The interpolation-based growth model has higher average dice score of 0.0647 and 0.0545, and higher average Jaccard index of 0.0673 and 0.0573, respectively, compared to the uniform- and gradient-based growth models.
The experimental results demonstrate the feasibility of calculating the proliferation and diffusion coefficients of the growth model based on patient-specific anatomy. The parameter space that characterizes spatial distribution of proliferation and diffusion coefficients is established and incorporated into the simulation of glioma growth. It enables to obtain patient-specific models about glioma growth by estimating and calibrating only a few model parameters.
脑肿瘤生长和演化的建模对于癌症诊断、预测临床进展和改善神经外科治疗效果至关重要。然而,现有的模型无法描述肿瘤细胞增殖和浸润的空间变化,难以实现对肿瘤生长的准确预测。
本文提出了一种利用磁共振图像上的反应扩散方程来模拟脑肿瘤生长的新模型。利用脑组织的异质性和肿瘤细胞的密度来估计脑肿瘤细胞的增殖和扩散系数。扩散系数用于描述肿瘤的扩散和浸润,通过比较白质和灰质的比例来计算;而增殖系数则通过肿瘤细胞的空间梯度来评估。此外,还通过反距离加权插值构建了参数空间来描述增殖系数的空间分布。
通过与患者的真实磁共振图像进行比较,对所提出模型预测的脑肿瘤生长进行了测试。实验和模拟结果表明,该方法能够准确地模拟脑肿瘤的生长。基于插值的生长模型的平均骰子得分分别为 0.0647 和 0.0545,平均杰卡德指数分别为 0.0673 和 0.0573,均高于基于均匀和梯度的生长模型。
实验结果证明了基于患者特定解剖结构计算生长模型增殖和扩散系数的可行性。建立了能够描述增殖和扩散系数空间分布的参数空间,并将其纳入脑肿瘤生长的模拟中。通过仅估计和校准少数几个模型参数,即可获得针对特定患者的脑肿瘤生长模型。