A Monte Carlo simulation framework for electron beam dose calculations using Varian phase space files for TrueBeam...

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Dosimetry

Background:

• Accurate electron Monte Carlo dose calculation is crucial for advanced radiotherapy.
• Vendor-provided phase space files require validation for clinical implementation.

Purpose of the Study:

• To develop and validate a Monte Carlo simulation framework for electron beam dose calculations.
• To assess the accuracy of vendor-provided Varian TrueBeam phase space files against measured data.

Main Methods:

• Utilized vendor-provided electron beam phase space files as input for EGSnrc simulations.
• Simulated various electron energies (6-20 MeV) and field sizes (3x3 to 25x25 cm²).
• Compared simulation results (percent depth dose, profiles, output factors) with ionization chamber and diode detector measurements.

Main Results:

• Percent depth dose and orthogonal profiles agreed within 2% or 1 mm.
• Discrepancies were minimal, generally within 1 mm for profiles and 2.5% for output factors.
• Excellent agreement was observed across standard and extended source-to-surface distances.

Conclusions:

• A validated Monte Carlo simulation framework for Varian TrueBeam electron beams was established.
• The framework demonstrates high accuracy for energies 6-20 MeV and various field sizes.
• This framework can support treatment planning for dynamic electron arc and other advanced techniques.