Speaker
Description
Nanoparticle enhanced radiotherapy under X-ray irradiation has been widely investigated as a promising strategy to locally modify energy deposition at the micrometric and nanometric scales. This method aims to optimize the patient’s cancer treatment by promoting the production of secondary particles in the vicinity of the nanoparticles and increasing local energy deposition while preserving surrounding healthy tissues, reducing organs at risk exposition.
Accurate characterization of these effects requires thorough dosimetric and microdosimetric approaches capable of linking radiation interactions with matter at the nanoparticle scale to spatial dose distributions within complex biological geometries.
Therefore, this study aims to analyse computed dose distribution in a voxelized three-dimensional cellular model, accounting for some sub-cellular compartments and different nanoparticle spatial distributions, using Monte Carlo simulations under Geant4.
To obtain the dose distribution within the cellular model, an initial simulation of a single nanoparticle irradiated in water using an X-ray beam was performed to generate a dose kernel. This dose kernel was applied to all nanoparticles distributed throughout the cellular model. The dose in each voxel of the cellular volume was then calculated by accounting for the contribution of all nanoparticles.
The methodology enables quantitative comparison between configurations with and without nanoparticles through dose enhancement metrics, while other metrics have been developped to quantify dose heterogeneities and anisotropy of energy deposition. This highlights the limitations of the current clinical use of average metrics such as mean dose when describing these distributions.