Estimation of Photon Specific Absorbed Fractions in Digimouse Voxel Phantom using Monte Carlo Simulation Code FLUKA

Area of Science:

• Medical Physics
• Radiological Dosimetry
• Voxel Phantom Research

Background:

• Preclinical studies predominantly use mice, necessitating accurate internal dose assessment.
• Specific absorbed fraction (SAF) values are critical for this dose assessment.
• Existing SAF values often rely on outdated human organ data and limited source-target pairs.

Purpose of the Study:

• To evaluate specific absorbed fraction (SAF) values for monoenergetic photons across a range of energies (15-4000 keV).
• To utilize the Digimouse voxel phantom and Monte Carlo code FLUKA for these evaluations.
• To consider a comprehensive list of organs as both sources and targets for SAF calculations.

Main Methods:

• Employed the Digimouse voxel phantom model.
• Utilized the FLUKA Monte Carlo simulation code.
• Adopted organ compositions and densities from ICRP Publication 110.

Main Results:

• Presented evaluated organ masses and SAF values in tabular format.
• Observed that SAF values decrease with increasing source-to-target distance and photon energy.
• Noted that SAF values are inversely related to target organ mass and that lung composition significantly impacts SAF.

Conclusions:

• The generated SAF values are essential for calculating absorbed doses in various mouse organs.
• This study provides updated and specific SAF data for mouse dosimetry.
• Accurate SAF values are vital for reliable preclinical research involving mice.