Calculating biological dose distributions in hadrontherapy using GATE: the BioDose actor

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Biology

Background:

• Hadrontherapy offers precise dose delivery but requires accurate biological dose assessment.
• Current methods for calculating biological dose and uncertainty in treatment planning are complex and time-consuming.
• Validating biophysical models is crucial for optimizing clinical outcomes in hadrontherapy.

Purpose of the Study:

• To introduce the BioDoseActor, a novel tool for calculating biological dose and uncertainty in hadrontherapy treatment plans.
• To facilitate the validation of biophysical models and optimize clinical treatment planning.
• To improve the accuracy and efficiency of biological dose calculations.

Main Methods:

• Utilized pre-calculated linear-quadratic coefficients (α and β) from biophysical models (mMKM, NanOx).
• Covered various ions (H, He, Li, C, O) across a wide energy range (0.1–1000 MeV/u).
• Evaluated Geant4 step-size limitation methods (StepLimiter, StepFunction) for optimizing Monte Carlo simulations in SOBP distributions.

Main Results:

• The StepFunction method accelerated proton and carbon-ion simulations by 30.6x and 2x, respectively, with <2% difference in SOBP.
• Optimal StepFunction parameters were identified for clinical proton and carbon-ion beams.
• Calculated α, β coefficients, and RBE values (1.2-1.5 for protons, 2-3 for carbon ions) matched literature.
• Validated BioDoseActor on a clinical carbon-ion plan, generating physical/biological dose maps and DVHs.

Conclusions:

• BioDoseActor enables direct comparison of biophysical models for clinical integration.
• Optimized simulation parameters reduce computation time without sacrificing accuracy.
• Enhances the feasibility of biological dose-based treatment planning in hadrontherapy.