Sci-Fri PM: Planning-01: Measured electron and x-ray angular distribution data for benchmarking Monte Carlo codes.

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Physics

Background:

• In-air profiles are crucial for medical linear accelerator beam commissioning.
• Previous studies using Monte Carlo (MC) simulations showed good agreement with measurements but required adjustable beam parameters.
• Accurate simulation of medical accelerator output is essential for precise radiation therapy.

Purpose of the Study:

• To validate Monte Carlo (MC) simulations against experimental measurements for an electron accelerator with known initial beam parameters.
• To investigate the accuracy of EGSnrc MC calculations for electron scatter distributions and in-air photon beam profiles.
• To assess the sensitivity of photon beam profiles to variations in target material and geometry.

Main Methods:

• Performed experimental measurements of electron scatter distributions using various scattering foils and energies (13, 20 MeV).
• Conducted MC calculations using EGSnrc for electron beams and compared results with experimental data.
• Obtained in-air photon beam profiles using different targets and ion chambers; investigated geometric sensitivity.

Main Results:

• EGSnrc MC calculations for electron beams generally agreed with measurements within 1.5%.
• Preliminary results for photon beams show agreement between measured and calculated distributions to better than 5%.
• The study explored the impact of target materials and geometric variations on photon beam profiles.

Conclusions:

• Monte Carlo simulations, particularly EGSnrc, provide accurate predictions for medical linear accelerator output, especially for electron beams.
• The findings support the use of MC methods for reliable beam commissioning in radiation therapy.
• Further investigation into photon beam characteristics using MC simulations is warranted.