Tetrahedral-mesh-based computational human phantom for fast Monte Carlo dose calculations

Area of Science:

• Medical Physics
• Computational Biology
• Radiation Dosimetry

Background:

• Voxel phantoms have limitations in computational modeling.
• Polygonal surface phantoms offer improvements but suffer from slow Monte Carlo simulation speeds.

Purpose of the Study:

• To develop a novel tetrahedral mesh human phantom to enhance simulation speed.
• To compare the computational efficiency of tetrahedral mesh phantoms against polygonal surface phantoms.

Main Methods:

• Converted a polygonal surface phantom to a tetrahedral mesh geometry.
• Implemented the tetrahedral mesh phantom in Geant4 Monte Carlo code.
• Calculated organ doses and measured computation speed for comparison.

Main Results:

• Tetrahedral mesh phantoms demonstrated significant speed improvements, ranging from 150 to 832 times faster than polygonal phantoms for most particles and energies.
• For low-energy neutrons (0.01 and 1 MeV), speed improvements were less pronounced but still substantial (17.2 and 8.8 times, respectively).

Conclusions:

• Tetrahedral mesh phantoms offer a substantial speed advantage for Monte Carlo simulations in computational human modeling.
• This development addresses a critical limitation of polygonal phantoms, paving the way for faster and more efficient radiation dose assessments.