Commissioning and initial validation of Eclipse eMC algorithm for the electron FLASH research extension (FLEX) system...

Area of Science:

• Medical Physics
• Radiation Oncology
• Pre-clinical Research

Background:

• Ultra-high dose rate (UHDR) FLASH radiotherapy offers potential therapeutic advantages.
• Accurate dose calculation in treatment planning systems (TPS) is crucial for FLASH implementation.
• Commissioning advanced systems like the 16 MeV electron FLASH Extension (FLEX) in TPS is essential for research.

Purpose of the Study:

• To assess the feasibility of commissioning the 16 MeV FLEX system within a commercial TPS.
• To validate the accuracy of the electron Monte Carlo (eMC) algorithm for modeling FLASH beams.
• To enable in silico treatment planning and support pre-clinical studies using FLASH radiotherapy.

Main Methods:

• Commissioned the FLEX system using the eMC algorithm in a commercial TPS.
• Utilized radiochromic film for initial beam data measurements and validation.
• Compared TPS-calculated dose distributions against experimental measurements for the 16 MeV FLASH beam.

Main Results:

• The eMC algorithm accurately modeled the FLEX system, with calculated PDDs and profiles agreeing within 1% of measurements.
• Beam characteristics like flatness, symmetry, FWHM, and penumbra were well-reproduced.
• The model successfully captured the forward-peaked dose distribution of the FLASH beam, differentiating it from conventional electron beams.

Conclusions:

• Successful commissioning of the FLEX system in the TPS was achieved using the eMC algorithm.
• The validated TPS model accurately represents the FLASH beam's unique properties.
• This facilitates pre-clinical research and in silico planning for future clinical translation of FLASH radiotherapy.