Consistent and invertible deformation vector fields for a breathing anthropomorphic phantom: a post-processing framework for the XCAT phantom.

Consistent and invertible deformation vector fields for a breathing anthropomorphic phantom: a post-processing framework for the XCAT phantom.
Phys Med Biol. 2020 Apr 01;:
Authors: Eiben B, Bertholet J, Menten MJ, Nill S, Oelfke U, McClelland JR
Abstract
Breathing motion is challenging for radiotherapy planning and delivery. This requires advanced four-dimensional (4D)-imaging and motion mitigation strategies and associated validation tools with known deformations. Numerical phantoms such as the XCAT provide reproducible and realistic data for simulation-based validation. However, the XCAT generates partially inconsistent and non-invertible deformations where tumours remain rigid and structures can move through each other. We address these limitations by post-processing the XCAT deformation vector fields (DVF) to generate a breathing phantom with realistic motion and quantifiable deformation. An open-source post-processing framework was developed that corrects and inverts the XCAT-DVFs while preserving sliding motion between organs. Those post-processed DVFs are used to warp the first XCAT-generated image to consecutive time points providing a 4D phantom with a tumour that moves consistently with the anatomy, the ability to scale lung density as well as consistent and invertible DVFs. For a regularly breathing case, the inverse consistency of the DVFs was verified and the tumour motion was compared to the original XCAT. The generated...

Source: Physics in Medicine and Biology - March 31, 2020 Category: Physics Authors: Eiben B, Bertholet J, Menten MJ, Nill S, Oelfke U, McClelland JR Tags: Phys Med Biol Source Type: research