Feasibility of Plastic Scintillator Dosimeters for FLASH Therapy

To examine the capabilities of plastic scintillator dosimeters (PSDs) to accurately measure FLASH radiotherapy dose rates delivered with an x-ray tube.

2020 AAPM AM
D.Cecchi (1), F.Therriault-Proulx (2), M.Bazalova-Carter (1) | University of Victoria, Victoria, BC ,CA,, Medscint, QC, CA

Development and characterization of an optical fiber-based Cerenkov dosimeter

This study introduces a novel hybrid Cerenkov-scintillation dosimeter

E.Jean (1,2,3), S.Lambert-girard (3), F.Therriault-Proulx (3), L.Beaulieu (1,2) | CHU de Quebec – Universite Laval, QC, CA, Département de radio-oncologie et Axe Oncologie du CRCHU de Québec, QC, CA, MedScint, QC, CA

Small field dosimetry of a Varian TrueBeam High Definition MLC linear accelerator using theHyperscint RP200 scintillation detector.

To evaluate the performance of the new Hyperscint RP200 plastic scintillator for small field measurements of a Varian TrueBeam linear accelerator in comparison with the current state-of-the-art methodology in the clinic.

L.Gingras, B.Côté, F.Berthiaume, S.Lambert-Girard, D.Leblanc, L.Archambault, L.Beaulieu, F.Therriault-Proulx | CHU de Quebec – Universite Laval, QC, CA, Département de radio-oncologie et Axe Oncologie du CRCHU de Québec, QC, CA, MedScint, QC, CA

Development of a Novel Hybrid Scintillation-Cerenkov Detector for Simultaneous Dose and Irradiation Angle Measurements

This study introduces a novel hybrid detector capable of simultaneous dose and direct irradiation angle measurements based on Cerenkov angular dependency.

2021 AAPM AM
E.Jean (1,2), S.Lambert-girard (3), F.Therriault-Proulx (3), L.Beaulieu (1) | CHU de Quebec – Universite Laval, QC, CA, CHAUR, Trois-Rivieres, QC, CA , MedScint, QC, CA

Plastic and Lead-Doped Scintillators for Ultrahigh Dose-Rate Irradiations Delivered with An X-Ray Tube

To examine the capabilities of plastic scintillators of different compositions to accurately measure dose in high dose-rate dose irradiations delivered with an x-ray tube.

2021 AAPM AM
D.Cecchi (1), C.Gigeure (2), F.Larose (2), F.Therriault-Proulx (3), L.Beaulieu (2), M.Bazalova-Carter (1) | University of Victoria, Victoria, BC ,CA,, CHU de Quebec – Universite Laval, QC, CA, 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)

Deformable Scintillation Dosimeter: II. Real-Time Simultaneous Measurements of Dose and Tracking of Deformation Vector Fields

This article introduces a novel deformable dosimeter that can measure the dose distribution and track the deformation of a material during radiotherapy treatments using the HYPERSCINT dosimetry system. The dosimeter is made of an array of 19 scintillating fiber detectors embedded in a cylindrical elastomer matrix. It is imaged by two pairs of stereoscopic cameras that record the position, angulation and dose of the scintillators.

Physics in Medicine & Biology
Emily Cloutier (1,2), Luc Beaulieu(1,2), Louis Archambault (1,2) | 1. Service de physique médicale et Axe Oncologie du Centre de recherche, CHU de Québec-Université Laval, Canada, 2. Département de physique, de génie physique et d’optique, et Centre de recherche sur le cancer, Université Laval, Québec, 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.

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