Calculation of the initial DNA damage induced by alpha particles in comparison with protons and electrons using...

Area of Science:

• Radiation biology
• Biophysics
• Computational physics

Background:

• Ionizing radiation induces DNA damage, including single- and double-strand breaks (SSBs and DSBs), and base lesions.
• Understanding radiation-induced DNA damage is crucial for radiobiology and radiation protection.

Purpose of the Study:

• To simulate the interaction of alpha particles with DNA in liquid water using Geant4-DNA.
• To quantify DNA damage, specifically SSBs and DSBs, and analyze damage complexity.

Main Methods:

• Simulations in a spherical water medium using a B-DNA model.
• Classification of DNA damage and complexity based on energy deposition (>17.5 eV) and hydroxyl radical reactions (probability 0.13).
• Analysis of 2-20 MeV alpha particle interactions.

Main Results:

• Over 65% of energy deposition events within the DNA volume resulted in DNA breaks.
• Higher deposited energies correlated with an increased frequency of complex DNA damage.
• DSB yield results showed good agreement with experimental data and were largely independent of particle type at high LET.

Conclusions:

• The study confirms the significant contribution of secondary electrons to DNA damage at high LET.
• Simulation results align well with experimental findings for DSB yields.
• The Geant4-DNA toolkit provides a valuable tool for studying radiation-induced DNA damage.