Coupling a 3D tissue model to a 1D vascular network
This was joint work with the late J. Tinsley Oden at the Oden Institute, UT Austin, and colleagues at the Technical University of Munich. The study analyzed a 3D-1D model of tumor growth that couples flow and nutrient transport in the vessel network to nutrient and tumor evolution in the tissue domain, and established well-posedness for the resulting coupled multidimensional nonlinear model. See the article.
Figure 1 shows the tumor advancing toward the nutrient-rich artery at right. The top row tracks the φ_T = 0.8 contour of the total tumor volume fraction, the sum of the proliferative, hypoxic and necrotic cell species. The bottom row separates the necrotic (φ_N = 0.4, black), hypoxic (φ_H = 0.45, orange) and proliferative (φ_P = 0.5, green) populations. Figure is taken from article.

Growing the vasculature with the tumor
The subsequent study added angiogenesis. Nutrient-starved tumor cells release tumor angiogenesis factors that stimulate nearby vessels to grow toward the tumor, altering the coupled supply of nutrients and the evolution of the tumor. The resulting paper is Fritz et al. (2021).
Figure 2 demonstrates the angiogenesis effect and simultaneous tumor growth. Figure 3 shows quantities of interest — total tumor φ_T and the proliferative φ_P, hypoxic φ_H and necrotic φ_N masses — with and without angiogenesis. Angiogenesis is stochastic, so the simulation was run repeatedly to capture the variation in those quantities. Figures 2 and 3 and the simulation videos are from Fritz et al. (2021).


What it established, and where it led
This project concluded at the end of the Oden Institute appointment. Its central computational contribution was a mixed-dimensional formulation coupling an evolving one-dimensional vascular network and dynamic flow to transport and growth in a three-dimensional tissue domain.
The predictive-science questions developed around that model later informed work on model-error estimation, Bayesian calibration, optimal experimental design and reliable scientific computing.
Publications
- Marvin Fritz, Prashant K. Jha, Tobias Köppl, J. Tinsley Oden, Andreas Wagner, Barbara Wohlmuth, Modeling and Simulation of Vascular Tumors Embedded in Evolving Capillary Networks, Computer Methods in Applied Mechanics and Engineering, 2021.
- David A. Hormuth II, Caleb M. Phillips, Chengyue Wu, Ernesto A. B. F. Lima, Guillermo Lorenzo, Prashant K. Jha, Angela M. Jarrett, J. Tinsley Oden, Thomas E. Yankeelov, Biologically-Based Mathematical Modeling of Tumor Vasculature and Angiogenesis via Time-Resolved Imaging Data, Cancers, 2021.
- Marvin Fritz, Prashant K. Jha, Tobias Köppl, J. Tinsley Oden, Barbara Wohlmuth, Analysis of a New Multispecies Tumor Growth Model Coupling 3D Phase-Fields With a 1D Vascular Network, Nonlinear Analysis: Real World Applications, 2021.