Approximating tumor induced brain deformation using directly manipulated free form deformation

In the present work a novel approach for simulating the mass effect of primary brain tumors is described. The progression of the tumor is modeled by means of a deterministic reaction-diffusion equation. To account for the expansive nature of the tumor, the computed tumor cell density is linked to a parametric deformation model. This model is based on the directly manipulated free form deformation. In order to establish spatial correspondence between two successive simulation time points, landmarks, which are attached to the boundary of the gross tumor volume, are tracked. The deformation of rigid structures, i.e. the skull, is prevented by introducing fixed shielding landmarks. In a refinement step an adaptive landmark scheme ensures a dense sampling of the tumor isosurface, which allows for an appropriate representation of the tumor shape. First qualitative results demonstrate the capability of the described method, which allows for plausibly approximating mass effect of diffusive brain tumors.