Phase space determination from measured dose data for intraoperative electron radiation therapy

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Dosimetry

Background:

• Accurate Monte Carlo (MC) dose calculations are crucial for intraoperative electron radiation therapy (IOERT).
• Characterizing medical linear accelerator beams is essential for reliable MC simulations.
• Traditional methods often require complex accelerator head simulations.

Purpose of the Study:

• To present a novel procedure for characterizing medical linear accelerator beams for IOERT MC dose calculations.
• To avoid detailed simulations of the accelerator head by relying on dose measurements.
• To enable rapid, machine-specific tuning of particle phase space information.

Main Methods:

• Utilized an iterative expectation-maximization maximum-likelihood (EM-ML) algorithm.
• Employed dose measurements in homogeneous media (water and/or air) as input.
• Extracted particle phase space information (energy spectra, spatial distribution, emission angle).

Main Results:

• The developed procedure successfully derived accurate particle phase space information (PHSP) from dose measurements.
• MC simulations using the derived PHSP showed good agreement with reference simulations.
• The method allowed for efficient, machine-specific tuning in minutes.

Conclusions:

• Dose measurements can be effectively used to derive accurate particle phase space information for IOERT MC dose estimations.
• This procedure simplifies and accelerates the process of preparing linear accelerator data for MC simulations.
• The findings support the use of this method for enhancing the accuracy and efficiency of IOERT treatment planning.