Electron beam response corrections for an ultra-high-dose-rate capable diode dosimeter

Area of Science:

• Medical Physics
• Radiation Oncology
• Dosimetry

Background:

• Ultra-high-dose-rate (UHDR) electron beams are integral to FLASH studies and clinical translation of FLASH Radiotherapy (RT).
• The EDGE diode detector shows promise for UHDR dosimetry but exhibits beam energy dependency.

Purpose of the Study:

• Characterize EDGE detector response across varying electron beam energies under UHDR conditions.
• Validate Monte Carlo (MC) model-derived correction factors for the EDGE detector against experimental measurements, especially at UHDR.

Main Methods:

• Measured percentage depth doses (PDDs) using EDGE detectors and films for UHDR electron beams.
• Developed a detailed MC model of the EDGE detector and calculated water/silicon dose ratios for mono-energetic electron beams.
• Established an analytical method to correct PDD measurements from EDGE detectors.

Main Results:

• Water/silicon dose ratio showed a decrease with lower electron beam energy.
• Applied corrections resulted in good agreement between EDGE detector and film PDD measurements for UHDR electron beams.
• Correction factors were validated for UHDR electron beam dosimetry.

Conclusions:

• The study derived the electron beam response of the UHDR-capable EDGE detector using a Monte Carlo model.
• An analytical correction approach was validated for UHDR electron beam PDDs.
• The EDGE detector demonstrated its capability for accurate PDD measurements in UHDR electron beam applications.