A method to correct for temperature dependence and measure simultaneously dose and temperature using a plastic scintillation detector

Plastic scintillation detectors work well for radiation dosimetry. However, they show some temperature dependence, and a priori knowledge of the temperature surrounding the plastic scintillation detectors is required to correct for this dependence.

PHYSICS IN MEDICINE & BIOLOGY
F.Therriault-Proulx, L.Wooton, S.Beddar | Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

FLASH Irradiation of Drosophila Melanogaster Using Low Energy X-Rays

To investigate the capability of low energy x-rays to elicit the FLASH effect, Drosophila melanogaster larvae were irradiated with ultrahigh dose-rate and conventional radiotherapy dose rates using an inexpensive x-ray tube system. Dosimetry was performed with plastic scintillators and radiochromic film, and the differential survival observed in this work suggests that continuous 120 kVp x-rays can induce a FLASH effect.

2022 AAPM ANNUAL MEETING
A.Hart, J.Dudzic, J.Eby, S.Perlman, M.Bazalova-Carter | University of Victoria, Victoria, BC ,CA

Pre-Clinical and Clinical Evaluation of the HYPERSCINT Scintillation Dosimetry Research Platform

The purpose of this work is to evaluate the HYPERSCINT scintillation dosimetry research platform (Medscint Inc., Quebec City, Canada) designed for clinical QA for use in in-vivo dosimetry measurements.

2020 AAPM AM
I.Schoepper, E.Trestrail, S.Dieterich, M.Kent | WR Pritchard Veterinary Medical Teaching Hospital, UC Davis School of Veterinary Medicine UC Davis School Of Veterinary Medicine, Pacific Crest Medical Physics ,Chico, CA, UC Davis Medical Center, Sacramento, CA, Surgical and Radiological Sciences, UC Davis School of Veterinary Medicine, Davis, CA

Evaluation of scintillation detectors for ultrahigh dose-rate x-ray beam dosimetry

FLASH-Radiotherapy is an emerging ultrahigh dose rates radiotherapy technique, and animal studies have demonstrated the safety and efficacy of the technique in cancer treatment. A reliable real-time dosimeter system is crucial for the characterization of the so-called ‘FLASH-effect’, and an accurate beam delivery. This study aims to benchmark the performance of optical fiber inorganic scintillating detectors (ISDs) with plastic scintillating detectors (PSDs) for an ultrahigh dose-rate x-ray beam irradiation. Measurements includes : relative scintillator output, signal linearity with dose and dose rate, signal-to-noise ratio (SNR), signal stability and reliability.

The PSDs resulted in the highest reliability for a UHDR beam measurement with a CV of <0.1% while the Gd2O2S:Tb showed excellent repeatability (coefficient of variation (CV) <0.1%) compared to other detectors. All detectors showed good linearity with tube current (R2 < 0.975) and shutter exposure (R2 >0.999).

Proc Spie
Shahirah Shaharuddin (1), Alexander Hart (2), Magdalena Bazalova-Carter (2), Luc Beaulieu (3), Cloe Giguere (3), Christoph Kleefeld (1), Mark J. Foley (1) | 1. National University of Ireland, Galway (Ireland), 2. University of Victoria (Canada), 3 University Laval (Canada)

Real-time dosimetry of ultrahigh dose-rate x-ray beams using scintillation detectors

FLASH radiation therapy using an ultrahigh dose-rate beam is found to eradicate tumours whilst significantly reducing radiation-induced tissue toxicity. A real-time dosimetry system is required for the technique to be implemented clinically and for further preclinical studies. This study aimed to optimize the design of scintillating detectors using inorganic materials for real-time dosimetry in ultrahigh dose-rate radiation applications. Inorganic scintillator detectors were fabricated using phosphor-based scintillating materials (Gd2O2S:Tb, La2O2S:Tb, and La2O2S:Eu) coupled with optical fibers. The initial results in ultrahigh dose-rate x-ray irradiation showed excellent linearity with signal independent of the dose rate and dose delivered. A hyperspectral approach is adopted in this study to account for the stem effect that occurs within the high energy typically used in radiotherapy.

IEEE
Shahirah Shaharuddin (1), Alexander Hart (2), Daniel D. Cecchi (2), Magdalena Bazalova-Carter (2), Mark Foley (1) | 1. School of Physics, National University of Ireland Galway, Ireland, 2. Department of Physics & Astronomy, University of Victoria, Canada