Determining organ dose conversion coefficients for external neutron irradiation by using a voxel mouse model

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Computational Biology

Background:

• Accurate neutron radiation dose assessment is crucial for evaluating biological effects.
• Voxel models and Monte Carlo simulations are established methods for radiation transport calculations.

Purpose of the Study:

• To calculate neutron fluence-to-dose conversion coefficients for a voxel mouse model.
• To evaluate the impact of neutron energy and irradiation geometry on organ dose.
• To support neutron radiation effect evaluations.

Main Methods:

• Utilized a developed voxel mouse model.
• Employed the Monte Carlo N-particle (MCNP) code for simulations.
• Simulated 37 monodirectional monoenergetic neutron beams (10^-9 MeV to 20 MeV) under five irradiation geometries (left lateral, right lateral, dorsal-ventral, ventral-dorsal, isotropic).

Main Results:

• Calculated neutron fluence-to-dose conversion coefficients for selected organs.
• Demonstrated that neutron dose conversion coefficients are sensitive to irradiation geometry below 1 MeV.
• Highlighted the influence of neutron energy and organ location on organ dose.

Conclusions:

• Neutron dose assessment requires consideration of irradiation geometry, particularly for energies under 1 MeV.
• The developed voxel mouse model and MCNP simulations provide valuable data for neutron radiation effect evaluation.
• Findings contribute to a better understanding of neutron dosimetry in biological systems.