EFLASH Dosimetry On a Conventional Linac Using Pulse-Gated Delivery

To build on previous experiments and improve reproducibility of electron FLASH delivery on a conventional linear accelerator, a pulse-gating circuit was constructed and tested with several dosimeters including : a 0.01cc volume ion chamber, optically stimulated luminescence dosimeters (OSLDs), Gafchromic MD film and a novel plastic scintillation detector with spectral analysis (HYPERSCINT).

2021 AAPM ANNUAL MEETING
C.Duzenli, C.Mendez, M.Petric, J.Sweeney, D.Ta, T.Karan | BC Cancer, Vancouver, BC, CANADA

Dosimetric Characterization of the ARIEL 10 MV X-Ray Ultrahigh Dose-Rate (FLASH) Irradiation Platform at TRIUMF

The purpose was to characterize the beam delivery capabilities and dose rates achievable on the new ultrahigh dose-rate 10MV x-ray irradiation platform at TRIUMF. Beam commissioning and dosimetry have been conducted on the ARIEL x-ray FLASH irradiation platform using film doses and scintillators. Measured dose rates support that the 10MV x-ray beam may be used as a UHDR source compatible with FLASH radiobiological experiments.

2022 AAPM ANNUAL MEETING
N.Esplen (1), L.Egoriti (2), T.Planche (3), A.Hart (1), B.Paley (3), C.Hoehr (3), A.Gottberg (3), M.Bazalova-Carter (1) | 1- University of Victoria, BC ,CA, 2- University of British Columbia, BC, CA, 3- TRIUMF, BC, CA

Plastic Scintillation Detector for Dosimetric Characterization of Mobetron Ultra-High Dose Rate Electron Beam

The purpose is to present commissioning data for the MOBETRON electron radiation therapy system (IntraOp) at ultra-high dose rate using the HYPERSCINT plastic scintillation detector. The suitability of using a plastic scintillator as an active dosimeter for commissioning measurements of an ultra-high dose rate electron beam has been demonstrated (reference dosimetry, DPP, beam penetration, linearity with number of pulses, linearity with PW and short-term output stability).

2022 AAPM ANNUAL MEETING
G.Famulari (1), K.Zerouali (1), O.Piron (1), JF.Aubry (1), F.DeBlois (1), JF.Carrier (2) | 1- Centre Hospitalier de l’Universite de Montreal (CHUM), Montreal, QC, CA, 2- Departement de Physique, Universite de Montreal, Montreal, QC, CA

Comparative optic and dosimetric characterization of the HYPERSCINT scintillation dosimetry research platform for multipoint applications

This study introduces the HYPERSCINT research platform (HYPERSCINT-RP100, Medscint Inc., Quebec, Canada), the first commercially available scintillation dosimetry platform capable of multi-point dosimetry through the hyperspectral approach.

Phys Med Biol. 2021
E.Jean (1,2,3), F.Therriault-Proulx (4), L.Beaulieu (1,2) | Département de physique, génie physique et optique, et Centre de recherche sur le cancer, Université Laval, Québec, CA , Département de radio-oncologie et Axe Oncologie du CRCHU de Québec, QC, CA, Département de radio-oncologie du CIUSSS-MCQ, CHAUR de Trois-Rivières, Trois-Rivières, QC, Canada, MedScint, QC, 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