Mechanistic DNA damage simulations in Geant4-DNA part 1: A parameter study in a simplified geometry

Area of Science:

• Radiation physics
• Computational biology
• Radiochemistry

Background:

• Mechanistic modeling of DNA damage in Monte Carlo simulations is critical for understanding radiation effects.
• These simulations are highly sensitive to the parameters defining DNA damage, necessitating careful validation.

Purpose of the Study:

• To investigate the impact of different physics models and damage parameters on DNA damage estimation.
• To identify a consistent parameter set for mechanistic DNA damage simulations using Geant4-DNA.

Main Methods:

• Utilized a simple testing geometry within Geant4-DNA for mechanistic DNA damage simulations.
• Employed low energy electrons as primary particles to test various physics and damage model parameters.
• Focused on variations in scavenging and single-strand break induction parameters.

Main Results:

• The choice of physics model can alter the yield of physically induced strand breaks by up to a factor of two.
• Scavenging and physical/chemical single-strand break induction parameters showed even more significant consequences.
• A parameter set consistent with past studies was identified, highlighting the role of scavenging.

Conclusions:

• Physics models and parameter choices critically influence DNA damage simulation outcomes.
• Modeling of radical scavenging is essential for accurate simulation results.
• High-scavenging regimes (radicals within 1 nm of DNA) may offer a robust method for testing mechanistic DNA simulations.