Shielding variation effects for 250 MeV protons on tissue targets.

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Science

Background:

• Hadron therapy offers precise radiation delivery but necessitates robust radiation protection measures.
• Understanding radiation fields and dose equivalents is crucial for safeguarding personnel, patients, and the public.
• Computer simulations are vital for predicting and optimizing radiation shielding in treatment facilities.

Purpose of the Study:

• To analyze radiation protection challenges in hadron therapy using computer simulations.
• To evaluate the impact of shielding material properties on radiation fields and dose equivalents.
• To assess uncertainties arising from shielding materials and computational models.

Main Methods:

• Monte Carlo simulations were employed to model radiation transport (protons, neutrons, photons) in a simplified hadron therapy scenario.
• Cylindrical geometries represented the treatment room and patient at 250 MeV incident proton energy.
• Variations in concrete composition, density, and water content were systematically investigated to determine their influence on shielding effectiveness.

Main Results:

• Good agreement was observed between MCNPX and FLUKA simulation codes.
• Neutron ambient dose equivalent attenuation varied by -50% to +30% due to differences in concrete composition.
• An 8% change in concrete water content led to up to 20% variations in dose equivalent.

Conclusions:

• Shielding material properties, especially concrete composition and water content, introduce significant uncertainties in radiation dose estimations.
• Accurate modeling of shielding materials is essential for reliable radiation protection in hadron therapy.
• Simulation results underscore the need for careful consideration of material variations in designing effective radiation shielding for hadron therapy facilities.