Medical Applications of the PHITS Code (3): User Assistance Program for Medical Physics Computation

Area of Science:

• Medical Physics
• Computational Dosimetry
• Radiation Therapy

Background:

• Particle and Heavy Ion Transport code System (PHITS) is a versatile Monte Carlo simulation tool.
• Accurate simulation of radiation therapy requires precise input geometry and source definition.
• Bridging medical imaging data (DICOM) and simulation environments is crucial for treatment verification.

Purpose of the Study:

• To introduce DICOM2PHITS and PSFC4PHITS, user-assistance programs for medical physics PHITS applications.
• To facilitate the construction of voxel PHITS simulation geometry from patient CT DICOM data.
• To enable the conversion of IAEA phase-space file data into PHITS format for simulation sources.

Main Methods:

• DICOM2PHITS utilizes a conversion table from CT numbers to material compositions for geometry construction.
• PSFC4PHITS converts IAEA phase-space file data into a format compatible with PHITS simulations.
• Development is underway to convert PHITS dose distributions to DICOM RT-dose format.

Main Results:

• DICOM2PHITS successfully generates voxel PHITS simulation geometries from patient CT images.
• PSFC4PHITS efficiently converts IAEA phase-space data for use as PHITS simulation sources.
• These programs significantly aid users in applying PHITS for radiation therapy treatment planning verification.

Conclusions:

• DICOM2PHITS and PSFC4PHITS are valuable tools for enhancing the application of PHITS in medical physics.
• These programs simplify the integration of patient-specific data into radiation therapy simulations.
• Future development aims to further integrate DICOM treatment information (RT-plan, RT-structure) into PHITS workflows.