Diffusing alpha-emitters radiation therapy dosimetry: Geant4 multi-stage Monte Carlo modeling of sources

The authors aim to develop and validate a comprehensive 3D Monte Carlo model that integrates the entire decay chain of 224Ra, radionuclide diffusion, and particle energy-transfer physics to enhance dosimetry for Diffusing alpha-emitters Radiation Therapy (DaRT). Using the Geant4 toolkit, they successfully created a multi-stage Monte Carlo model that accurately simulates spatial and temporal dose distributions for various source configurations, demonstrating its potential for micro- and nanodosimetry as well as in-vivo detector analyses. The results indicate that the model's predictions align closely with existing analytical models, highlighting its effectiveness in complex dosimetry scenarios.