Track structure, radiation quality and initial radiobiological events: considerations based on the PARTRAC code...

Area of Science:

• Radiation biology
• Biophysics
• Computational modeling

Background:

• Decades of research highlight the importance of radiation track structures in determining biological effects.
• Monte Carlo codes, like PARTRAC, simulate radiation-matter interactions at the atomic level.

Purpose of the Study:

• This review presents the track structure theory and its extensions for non-DNA targets.
• It analyzes the role of radiation quality and track structure using the PARTRAC code.

Main Methods:

• The PARTRAC code simulates DNA damage in human cells by superimposing track structures in water onto an atomic DNA model.
• Analysis includes comparing calculated DNA fragmentation with experimental data for various radiation qualities.

Main Results:

• High-Linear Energy Transfer (LET) irradiation produces numerous small DNA fragments (<1 kbp), often undetected experimentally.
• Radiation track structure significantly influences DNA damage complexity.

Conclusions:

• Track structure is vital, especially the spatial distribution of DNA double-strand breaks (DSB) along the radiation track.
• The relative biological effectiveness (RBE) for DSB production can exceed 1, with high-LET radiation clusters potentially targeting specific cellular components.