Predicting stress and interstitial fluid pressure in tumors based on biphasic theory

The uncontrolled proliferation of cancer cells causes the growth of the tumor mass. Consequently, the normal surrounding tissue exerts a compressive force on the tumor mass to oppose its expansion. These stresses directly promote tumor metastasis and invasion and affect drug delivery. In the past, the mechanical behavior of solid tumors has been extensively studied using linear elastic and nonlinear hyperelastic constitutive models.In this study, we develop a two-dimensional biomechanical model based on the biphasic assumption of the solid matrix and fluid phase of the tissues. Heterogeneous vasculature and nonuniform blood perfusion are also investigated by incorporating in the model a necrotic core and a well-vascularized zone. The findings of our study demonstrate a significant difference between the linear and nonlinear tissue responses to stress, while the interstitial fluid pressure (IFP) distribution is found to be inde-pendent of the constitutive model. The proposed biphasic model may be useful for elasticity imaging techniques aiming at predicting stress and IFP in tumors.

Automated summary

The uncontrolled proliferation of cancer cells leads to tumor growth, which is opposed by compressive forces from the surrounding tissue. These forces promote tumor metastasis, invasion, and affect drug delivery. A two-dimensional biomechanical model based on the biphasic assumption of the solid matrix and fluid phase is developed in this study. Heterogeneous vasculature and nonuniform blood perfusion are also considered. The findings show differences in the tissue's response to stress between linear and nonlinear models, while the interstitial fluid pressure distribution is independent of the model used.