SU-E-T-473: Performance Assessment of the TOPAS Tool for Particle Simulation for Proton Therapy Applications

Area of Science:

• Medical Physics
• Computational Physics
• Radiotherapy Research

Background:

• Geant4 Monte Carlo simulations are crucial for proton therapy research.
• Existing tools can be complex for researchers and clinicians.
• There is a need for accessible and accurate simulation software.

Purpose of the Study:

• To introduce the TOPAS Tool for Particle Simulation (TOPAS).
• To validate TOPAS for various proton therapy setups.
• To ensure accurate Monte Carlo simulations for clinical applications.

Main Methods:

• TOPAS models passive scattering and scanning beam treatment heads.
• Patient geometry is modeled using CT images.
• Simulations include 4D capabilities for dynamic treatment variations.
• TOPAS was tested on UCSF eye treatment and MGH STAR/gantry beamlines.

Main Results:

• Accurate depth dose distributions were simulated for dynamic energy modulation.
• Distal/proximal ranges and SOBP shapes matched measurements at the MGH STAR beamline.
• TOPAS simulations met clinical accuracy requirements for passive scattering.
• Fluence maps were generated for various scanning modes, including target tracking.

Conclusions:

• TOPAS functionality is demonstrated through successful simulations.
• Results show strong agreement with measured data.
• TOPAS accurately simulates 3D and 4D proton therapy beam delivery.