A Three-dimensional tumor growth model and its boundary instability
Jian-Guo Liu, Thomas Witelski, Xiaoqian Xu, Jiaqi Zhang
TL;DR
This work extends Feng et al. 2023 by developing a 3D sharp-interface tumor growth model and analyzing boundary stability through perturbation theory with spherical harmonics, complemented by 2D ADI validation to match front propagation speeds. By deriving and analyzing evolution functions that govern δ^{-1} dδ/dt, the authors identify a consistent in vitro stability across dimensions and a dimension- and parameter-dependent transition to instability in vivo, including a proposed λ^*(ℓ) threshold. The combination of analytical constructions (including 3D spherically symmetric solutions and perturbations) with numerical ADI verification provides a robust framework for predicting front dynamics in 3D tumor growth and offers insights into how nutrient supply and consumption shape tumor morphology. The results have potential implications for understanding malignant boundary evolution and for developing computational tools to anticipate tumor boundary behavior in realistic three-dimensional geometries.
Abstract
In this paper, we investigate the tumor instability by employing both analytical and numerical techniques to validate previous results and extend the analytical findings presented in a prior study by Feng et al 2023. Building upon the insights derived from the analytical reconstruction of key results in the aforementioned work in one dimension (1D) and two dimensions (2D), we extend our analysis to three dimensions (3D). Specifically, we focus on the determination of boundary instability using perturbation and asymptotic analysis along with spherical harmonics. Additionally, we have validated our analytical results in a two-dimensional framework by implementing the Alternating Directional Implicit (ADI) method, as detailed in Witelski and Bowen (2003). Our primary focus has been on ensuring that the numerical simulation of the propagation speed aligns accurately with the analytical findings. Furthermore, we have matched the simulated boundary stability with the analytical predictions derived from the evolution function, which will be defined in subsequent sections of our paper. These alignment is essential for accurately determining the stability or instability of tumor boundaries.
