Optimizing the modified microdosimetric kinetic model input parameters for proton and ⁴He ion beam therapy...

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiobiology

Background:

• Accurate prediction of relative biological effectiveness (RBE) is essential for proton and helium-4 ion beam therapy.
• RBE calculations are critical for treatment planning, especially when comparing biologically optimized plans.
• Existing models require adaptation for precise RBE prediction in proton and helium-4 ion therapy.

Purpose of the Study:

• To adapt the microdosimetric kinetic model (MKM) for predicting RBE in proton and helium-4 ion beams.
• To validate the modified MKM against experimental RBE data and in vitro cell survival data.
• To assess the model's suitability for clinical treatment planning in particle therapy.

Main Methods:

• Modified the microdosimetric kinetic model (MKM) by tuning domain and nucleus radii parameters.
• Validated the model using an experimental database of initial RBE data for proton and helium-4 ions.
• Tested the model's predictive accuracy against in vitro cell survival data for A549 and RENCA cell lines.

Main Results:

• The modified MKM accurately reproduced experimental RBE data for proton and helium-4 ions.
• The model achieved a mean absolute survival variation within 2% for protons and 5% for helium-4 ions.
• Sensitivity analysis confirmed the robustness of the model's predictions regarding key parameters.

Conclusions:

• The adapted MKM provides accurate RBE predictions for proton and helium-4 ion beams.
• The model demonstrates satisfactory agreement with experimental and in vitro data in clinical scenarios.
• The modified MKM is a promising tool for treatment planning in proton and helium-4 ion therapy.