Golden beam data for proton pencil-beam scanning.

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Therapy

Background:

• Pencil-beam scanning (PBS) utilizes ion beams for precise radiation delivery.
• Accurate characterization of beam interactions is crucial for effective treatment planning.
• Current methods require extensive measurements for individual PBS systems.

Purpose of the Study:

• To develop a standardized, data-driven approach for quantifying proton beam interactions in media.
• To reduce the complexity of characterizing individual PBS delivery systems.
• To establish a 'Golden' beam dataset for improved accuracy in treatment planning.

Main Methods:

• Derivation of a 'Golden' beam dataset based on fundamental physical interactions of proton beams.
• Quantification of depth-dose distributions, including primary (Coulomb) and secondary (nuclear) scatter components.
• Reduction of system-specific measurements to energy spread and initial phase space.

Main Results:

• The 'Golden' beam dataset accurately describes pristine Bragg peak depth-dose distributions.
• Required measurements for PBS systems are significantly reduced.
• Absolute dosimetry in Gy(RBE) mm² Gp⁻¹ provides direct mapping to treatment planning parameters.
• Validation on PBS systems confirmed dosimetry within clinical tolerances.

Conclusions:

• The 'Golden' beam dataset offers a robust and efficient method for characterizing proton beams in PBS.
• This approach simplifies and enhances the accuracy of radiation therapy treatment planning.
• It enables precise absolute dosimetry, crucial for patient safety and treatment efficacy.