Two-dimensional pencil beam scaling: an improved proton dose algorithm for heterogeneous media.

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Biology

Background:

• Proton beam therapy requires fast and accurate dose algorithms for treatment plan optimization.
• Current methods struggle with accuracy in heterogeneous anatomical regions.
• Existing fast algorithms lack the precision needed for clinical dose distributions.

Purpose of the Study:

• To develop a novel proton dose calculation algorithm addressing the speed-accuracy trade-off.
• To improve dose calculation accuracy for complex and heterogeneous targets in proton therapy.
• To enable clinically acceptable dose distributions in conformal proton therapy.

Main Methods:

• A new algorithm based on additional scaling of lateral proton fluence was derived.
• A two-dimensional (2D) scaling method was developed and tested.
• The new method was compared against standard pencil beam calculations and Monte Carlo simulations (GEANT).

Main Results:

• The new algorithm achieves absorbed dose calculation accuracy comparable to Monte Carlo simulations.
• The computational time is only modestly increased compared to standard pencil beam methods.
• The 2D scaling method demonstrated effectiveness across various phantom materials, including bone, muscle, fat, and air.

Conclusions:

• The new proton dose algorithm offers a significant improvement in accuracy for proton therapy.
• It provides a viable solution for optimizing treatment plans in complex clinical cases.
• This algorithm has the potential to enhance outcomes in highly conformal proton therapy.