GPU-accelerated Monte Carlo simulation of electron and photon interactions for radiotherapy applications

Abstract

Objective. The Monte Carlo simulation software is a valuable tool in radiation therapy, in particular to achieve the needed accuracy in the dose evaluation for the treatment plans optimisation. The current challenge in this field is the time reduction to open the way to many clinical applications for which the computational time is an issue. In this manuscript we present an innovative GPU-accelerated Monte Carlo software for dose valuation in electron and photon based radiotherapy, developed as an update of the FRED (Fast paRticle thErapy Dose evaluator) software. Approach. The code transports particles through a 3D voxel grid, while scoring their energy deposition along their trajectory. The models of electromagnetic interactions in the energy region between 1MeV - 1 GeV available in literature have been implemented to efficiently run on GPUs, allowing to combine a fast tracking while keeping high accuracy in dose assessment. The FRED software has been bench-marked against state-of-art full MC (FLUKA, GEANT4) in the realm of two different radiotherapy applications: Intra-Operative Radio Therapy and Very High Electron Energy radiotherapy applications. Results. The single pencil beam dose-depth profiles in water as well as the dose map computed on non-homogeneous phantom agree with full-MCs at 2\% level, observing a gain in processing time from 200 to 5000. Significance. Such performance allows for computing a plan with electron beams in few minutes with an accuracy of $\sim$\%, demonstrating the FRED potential to be adopted for fast plan re-calculation in photon or electron radiotherapy applications.

Electron FLASH radiotherapy in vivo studies. A systematic review

“…Nevertheless, electrons are more flexible and can easily reach high DPP values necessary to trigger the flash effect compared to protons. Franciosini et al have shown with Monte Carlo simulations that an energy of 100-250 MeV, multiple fields and a pencil beam scan are required to obtain satisfactory dosimetric conformations in cases of deep tumors by using fields of few mm (80). For this reason, new linear accelerators able to deliver UHDR with high-energy electrons (VHHE) must be developed in the future for these treatments.…”

Generalisation of radiotherapy dose calculation for Monte Carlo algorithm combined with 3D Swin-Unet: a multi-institutional IMRT evaluation

“…However, in clinical radiotherapy more accurate dose calculation methods, such as the Monte Carlo algorithm, and higher computational efficiency are expected. In recent years, there have been two primary strategies to improve the computational efficiency of the Monte Carlo algorithm: simplifying the calculation algorithm, or using graphic processing unit (GPU) acceleration technology (Fippel 1999, Franciosini et al 2023. A recently proposed dose calculation method combining deep learning and the Monte Carlo algorithm, considering the calculation accuracy and computational efficiency, holds the potential for generalisation to dose calculation algorithms used in clinical practice (Kontaxis et al et al 2020, Neph et al 2021, Xiao et al 2022, Zhang et al 2022.…”