DOSIMETRY WITH THE ABILITY TO DISTINGUISH PULSED AND NON-PULSED DOSE CONTRIBUTIONS

Area of Science:

• Medical Physics
• Radiation Detection and Measurement

Background:

• Accurate dosimetry is critical in radiation therapy for effective treatment and patient safety.
• Pulsed radiation fields, common in radiotherapy, present unique challenges for traditional dosimetry systems due to pile-up effects.

Purpose of the Study:

• To present an active dosimetry system capable of real-time distinction between pulsed and non-pulsed radiation contributions.
• To investigate the system's performance in measuring absorbed dose rates in complex radiation fields.

Main Methods:

• Utilizing a fast tissue-equivalent plastic scintillator to minimize pile-up effects.
• Employing a fully digital signal processing board for real-time data analysis and adjustable system parameters.
• Conducting measurements in a simulated radiotherapeutic photon field and a constant radiation field.

Main Results:

• Demonstrated a linear relationship between the pulsed radiation contribution and accelerator current up to 8 μGy h⁻¹.
• Quantified the pulsed radiation dose rate increase to (26.2 ± 0.9) nGy h⁻¹ per 1 μA increase in accelerator current, accounting for pile-up events.

Conclusions:

• The developed active dosimetry system provides accurate absorbed dose rate measurements in pulsed radiation fields.
• The system's ability to differentiate radiation components and minimize pile-up effects enhances dosimetry precision in radiotherapy applications.