Investigation of hydrogen peroxide yields and oxygen consumption in high dose rate irradiation: a TOPAS-nBio Monte Carlo study.

TOPAS-nBio enables users to simulate dose rate-dependent radiation chemical yields in water radiolysis accounting for inter-track and long-term chemistry for pulsed irradiation. This study aims to extend the TOPAS-nBio chemistry for the special case of continuous high-dose rate scenario, where both intertrack and longer time reactions need to be considered, and to quantitatively validate the extended framework by comparing the results with experimental data.The inter-track chemistry and escape-values were first evaluated by the independent reaction time method.

Modeling the oxygen effect in DNA strand break induced by gamma-rays with TOPAS-nBio.

To present and validate a method to simulate from first principles the effect of oxygen on radiation-induced double-strand breaks (DSBs) using the Monte Carlo Track-structure code TOPAS-nBio.Two chemical models based on the oxygen fixation hypothesis (OFH) were developed in TOPAS-nBio by considering an oxygen adduct state of DNA and creating a competition kinetic mechanism between oxygen and the radioprotective molecule WR-1065. We named these models 'simple' and 'detailed' due to the way they handle the hydrogen abstraction pathways.

TOPAS-Tissue: A Framework for the Simulation of the Biological Response to Ionizing Radiation at the Multi-Cellular Level.

This work aims to develop and validate a framework for the multiscale simulation of the biological response to ionizing radiation in a population of cells forming a tissue. We present TOPAS-Tissue, a framework to allow coupling two Monte Carlo (MC) codes: TOPAS with the TOPAS-nBio extension, capable of handling the track-structure simulation and subsequent chemistry, and CompuCell3D, an agent-based model simulator for biological and environmental behavior of a population of cells. We verified the implementation by simulating the experimental conditions for a clonogenic survival assay of a 2-D PC-3 cell culture model (10 cells in 10,000 µm) irradiated by MV X-rays at several absorbed dose values from 0-8 Gy.

An interface tool to parametrize treatment plans for the TrueBeam radiotherapy system into TOPAS parameter control files for Monte Carlo simulation.

Purpose: The Monte Carlo (MC) method, the gold standard method for radiotherapy dose calculations, is underused in clinical research applications mainly due to computational speed limitations. Another reason is the time-consuming and error prone conversion of treatment plan specifications into MC parameters. To address this issue, we developed an interface tool that creates a set of TOPAS parameter control files (PCF) from information exported from a clinical treatment planning system (TPS) for plans delivered by the TrueBeam radiotherapy system.

A framework for in-field and out-of-field patient specific secondary cancer risk estimates from treatment plans using the TOPAS Monte Carlo system.

. To allow the estimation of secondary cancer risks from radiation therapy treatment plans in a comprehensive and user-friendly Monte Carlo (MC) framework..