Radiation transport calculations for 50 MV photon therapy beam using the Monte Carlo code GEANT4

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Accelerators

Background:

• Developing advanced radiotherapy techniques for precise dose delivery is crucial.
• Narrow scanned photon beams offer potential for targeted cancer treatment.
• Efficient electron management within treatment heads is a key challenge.

Purpose of the Study:

• To introduce and evaluate a new thin transmission target technique for fast dose delivery using narrow scanned photon beams.
• To investigate electron-photon transport within a treatment head using Monte Carlo simulations.
• To assess the feasibility of this technique for future narrow photon beam therapy.

Main Methods:

• Utilized a thin transmission target with high-energy electron beams (50-100 MeV).
• Employed the Geant4 Monte Carlo simulation toolkit to model electron-photon transport.
• Compared simulation results of radial dose profiles with experimental data.

Main Results:

• The developed technique produces narrow, intense high-energy bremsstrahlung beams.
• Geant4 simulations showed good agreement with experimental radial dose profiles (2-10% difference).
• Preliminary collector designs aimed to minimize secondary particle contamination.

Conclusions:

• The thin transmission target technique is effective for fast dose delivery with narrow photon beams.
• Geant4 is a reliable tool for simulating electron-photon transport in treatment heads.
• This approach shows promise for advancing narrow photon beam therapy.