Monte Carlo dose calculation on deforming anatomy.
This article presents the implementation and validation of a dose calculation approach for deforming anatomical objects. Deformation is represented by deformation vector fields leading to deformed voxel grids representing the different deformation scenarios. Particle transport in the resulting deformed voxels is handled through the approximation of voxel surfaces by triangles in the geometry implementation of the Swiss Monte Carlo Plan framework. The focus lies on the validation methodology which uses computational phantoms representing the same physical object through regular and irregular voxel grids. These phantoms are chosen such that the new implementation for a deformed voxel grid can be compared directly with an established dose calculation algorithm for regular grids. Furthermore, separate validation of the aspects voxel geometry and the density changes resulting from deformation is achieved through suitable design of the validation phantom. We show that equivalent results are obtained with the proposed method and that no statistically significant errors are introduced through the implementation for irregular voxel geometries. This enables the use of the presented and validated implementation for further investigations of dose calculation on deforming anatomy.
ARTORG Center for Computer-Aided Surgery CCAS, University of Bern, Stauffacherstrasse, Switzerland. Matthias.Peterhans@istb.unibe.ch
Matthias
M
Peterhans
Daniel
D
Frei
Peter
P
Manser
Mauricio Reyes
MR
Aguirre
Michael K
MK
Fix
D000465:Algorithms; D006801:Humans; D009010:Monte Carlo Method; D009369:Neoplasms / Q000532:radiotherapy*; D019047:Phantoms, Imaging; D010825:Physics; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000706:statistics & numerical data*; D061106:Radiotherapy Setup Errors / Q000706:statistics & numerical data