A patient-specific framework for studying the influence of chemo-mechanical cues on brain tumour growth and surrounding healthy tissue damage. #

Chiara Giverso, Francesca Ballatore, Giulio Lucci

10:30 Tuesday in 4Q56.

Part of the Chemo-mechanical couplings in growing tissues session.

Abstract #

Brain tumours frequently grow along the fibres of the white matter or along vessels, following the physical structures in the neighbouring healthy tissue. Depending on the amount and orientation of such preferential paths and the availability of nutrients, brain cancers may appear very different from an individual to another and may invade different neurological areas. Furthermore, the tumour growth-induced compression may also corrupt brain functions in the healthy region and constrict the flow of cerebrospinal fluid in the brain ventricles. It is therefore important to reproduce through mathematical and computational models the patient-specific heterogeneity of brain microstructure and the mechanical behaviour of the brain tissue in order to correctly predict the progression of the pathology, the extent of the injured areas, and the effect of therapies. Motivated by these needs, we develop a mathematical multiphase model that explicitly includes brain hyperelasticity and couples solid and fluid stresses with brain tumour anisotropic growth and healthy tissue reorganization. Our mechanical description allows to evaluate the impact of the growing tumour mass on the surrounding tissue, quantifying the displacements inside the healthy region and the deformation of brain ventricles, which may obstruct the flow of cerebrospinal fluid. At the same time, the knowledge of the mechanical variables is used to model the stress-induced inhibition on growth, as well as to properly modify the preferential directions of white matter tracts as a consequence of deformations caused by the tumour. The simulations of our model are implemented in a personalized three-dimensional framework, which allows to incorporate the realistic brain geometry, the patient-specific diffusion and permeability tensors reconstructed from neuro-imaging data and to modify them as a consequence of the mechanical deformation due to cancer growth. Finally, we also account for the tumour response to the standard therapeutic treatment, such as radiation therapy and chemotherapy.