MOTION-INDUCED MONTE CARLO DOSE CALCULATION USING DEFORMABLETETRAHEDRAL MESHES

International audienceThe distribution patterns estimation of energy and dosein respiratory-induced organ motion represents a technicalchallenge for hadron therapy treatment planning. This paperfocuses on the comparison between deformable tetrahedralmeshes and the conventional voxel-based structures, usedas computational phantoms in four-dimensional dose calculations.The movement issued from deformable imageregistration of CT-images is used for both representations tocalculate the 4D dose distributions. An implementation ofthe dose computation method for tetrahedral meshes on adeformable anatomy in case of passive scattering beam lineis given using the Geant4 code. Tissue tracking is implicitlyperformed by the fact that the meshes maintain their topologyduring deformations, and the dose distribution is calculatedusing time-dependent tetrahedral density map issued from4D-CT scans. Our results show that dose distributions forvoxel and tetrahedral meshes are in good agreement, anddose homogeneity is almost the same