Evaluation of a new commercial Monte Carlo dose calculation algorithm for electron beams

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Dosimetry

Background:

• Accurate dose calculation is crucial for effective radiation therapy.
• Monte Carlo (MC) algorithms offer high precision but require rigorous validation.

Purpose of the Study:

• To validate the XiO EMC Monte Carlo dose calculation algorithm for electron beams.
• To assess its accuracy in both homogeneous and heterogeneous phantom conditions.

Main Methods:

• Comparison of calculated and measured dose distributions using 2D/3D gamma index metrics.
• Validation in homogeneous water phantoms and a 3D heterogeneous phantom simulating clinical anatomy.
• Utilized radiochromic film for measurements in heterogeneous media.

Main Results:

• Excellent agreement (≥97% passing 2%/2 mm gamma index) for depth dose curves and profiles in water.
• High accuracy (>98% passing 3%/2 mm gamma index) in heterogeneous phantoms, considering dose gradients.
• Minor discrepancies noted for a specific high-energy electron beam with small cutouts at extended SSD.

Conclusions:

• The XiO EMC algorithm provides clinically acceptable accuracy for electron beam dose calculations in water.
• Radiochromic film is a valuable tool for validating MC treatment planning systems in heterogeneous environments.