Four-dimensional Monte Carlo simulation of time-dependent geometries

Area of Science:

• Medical Physics
• Computational Physics
• Radiation Oncology

Background:

• Dynamic radiation therapy necessitates complex dose calculations due to time-varying treatment head geometries.
• Current Monte Carlo methods often require combining results from multiple simulations, which can be cumbersome and computationally intensive.
• Accurate dose calculation is crucial for optimizing treatment efficacy and minimizing side effects in radiation therapy.

Purpose of the Study:

• To present a novel technique for simulating time-dependent geometries in radiation therapy using Monte Carlo methods.
• To enable single, four-dimensional (4D) Monte Carlo simulations for dynamic treatment scenarios.
• To streamline and improve the efficiency of dose calculations in advanced radiation therapy techniques.

Main Methods:

• Development and implementation of a technique for simulating time-dependent geometries within a single Monte Carlo simulation.
• Utilized the GEANT4 Monte Carlo package for the simulation framework.
• Applied the technique to proton therapy applications, including variable magnet settings in beam scanning.

Main Results:

• Demonstrated the feasibility of simulating time-dependent geometries in a single 4D Monte Carlo run.
• Showcased results specifically for proton therapy scenarios.
• The presented technique offers a more integrated approach compared to combining multiple simulations.

Conclusions:

• The developed technique simplifies Monte Carlo dose calculations for dynamic radiation therapy.
• This approach enhances the efficiency and potentially the accuracy of dose calculations in proton therapy.
• Further applications in other dynamic radiation therapy techniques are anticipated.