gROS - Monte Carlo GPU modeling of Reactive Oxygen Species (ROS) during FLASH radiation therapy

• Applicants: Professor Dr. Kilian-Simon Baumann; Professor Joao Seco, Ph.D.; Privatdozentin Dr. Ulrike Theiß
• Subject Area: Medical Physics, Biomedical Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 550953943

The application of ultra-high dose rates (>40 Gy/s) or FLASH radiotherapy (FLASH-RT) has gained significant interest during the last years, when compared to conv-RT (given at 2 Gy/min) due to more than 50% reduction in toxicity in healthy lung tissue of mice. Despite extensive development of the Monte Carlo (MC) codes to FLASH-RT, the codes struggle to model accurately the chemical impact of the different pulse structures. The Monte Carlo codes have not been capable of explaining why the H2O2 yield is lower in FLASH beams relative to conv-RT beams in pure water. The goal of the project is to develop and customize gROS, a new MC tool capable of simulating the production and diffusion of ROS for various dose-rate and pulse structure deliveries of radiation dose. The gROS MC tool will be validated via measurements done in water (H2O) of ROS, H2O2 and O2 consumption, for the various pulse structures and dose rates. The gROS Monte Carlo will be tested at the Marburg Ion-Beam Therapy Center (MIT) facility for various cell types (cancer and healthy) and for particles: electrons, protons and carbon ions. The key objectives are (1) To develop a gROS Monte Carlo tool capable of simulating production and diffusion of ROS and H2O2 for various low (conv-RT) and ultra-high dose rate (FLASHRT) deliveries, for different pulse structures and at different oxygen concentrations within the medium; (2) To validate the gROS Monte Carlo tool based on measurements in H2O of O2 consumption and H2O2 (ROS) production for various pulse structures and at different oxygen concentrations within the medium; (3) To assess gROS estimate of ROS (H2O2) and O2 consumption by the radiation in an in-vitro 2D model of cancer and healthy cells irradiated with electrons, protons and carbon ions.

• DFG Programme: Research Grants