Investigation of temperature dependence of inorganic scintillators using the HYPERSCINT research platform

The temperature dependence of four inorganic scintillation detectors was examined spectrally using the HYPERSCINT Research Platform 200 under 6 MV photon irradiations from a LINAC. After varying only the temperature of the detectors, all scintillators demonstrated linearity when the change in photon counts with temperature in the full-width at half maximum of their spectrum are integrated. Establishing the magnitude of the temperature dependence of the materials is critical to decide whether correction factors are required. This is especially true in applications such as brachytherapy, where detectors equilibrise to body temperature.

Radiation Measurements
Owen McLaughlin (1), Michael Martyn (1,2), Christoph Kleefeld (1), Mark Foley (1) | 1. Physics Unit, School of Natural Sciences, University of Galway, Galway, Ireland, 2. Galway Clinic, Doughiska, Galway, Ireland

On the nature of the light produced within PMMA optical light guides in scintillation fiber-optic dosimetry

The goal of this study was to evaluate the nature of the stem effect light produced within an optical fiber, to quantify its composition, and to evaluate the efficiency of the chromatic technique to remove the stem effect. The chromatic stem effect removal technique is accurate in most of the situations. However, noticeable differences were obtained between very specific high-energy irradiation conditions. It would be advantageous to implement an additional channel in the chromatic stem effect removal chain or implement a spectral approach to independently remove the Cerenkov and the fluorescence components from the signal of interest. This would increase the accuracy and versatility of the actual chromatic stem effect removal technique.

F.Therriault-Proulx (1)(2), L.Beaulieu (2)(3), L.Archambault (2)(3), S.Beddar (4)(1) | 1- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA, 2- Département de Physique, de Génie Physique et d’Optique, Université Laval, Québec, Québec, Canada, 3- Département de Radio-Oncologie, Hôtel-Dieu de Québec, Centre Hospitalier Universitaire de Québec, Québec, Canada

Orthovoltage to Monoenergetic Photon Beam Energy Correction Factor for HyperScint Scintillation Dosimeter

The scintillator dosimetry system is a small-field dosimeter with reported energy independence down to 100-keV. This work investigates the energy dependence of the scintillator between a monoenergetic photon source and polyenergetic orthovoltage beam.

B. Insley, D. Bartkoski, L. Che Fru, M. Salehpour | M.D. Anderson Cancer Center, Houston, TX

A Novel Multi-Headed Scintillation Detector for Fast and Efficient Dose Measurements at Multiple Locations Simultaneously

To develop and quantify the performances of a novel multi-point scintillation detector having multiple heads connected to the same optical line, allowing real-time dose measurements simultaneously at 3 positions in non-contiguous space.

B.Lessard (1,2), Y.Lechasseur (3), S.Lambert-girard (3), F.Therriault-Proulx (3), L.Beaulieu (1,2), L.Archambault (1,2) | 1- Département de physique, génie physique et optique, et Centre de recherche sur le cancer, Université Laval, Québec, CA , 2- CHU de Quebec – Universite Laval, QC, Canada, 3- MEDSCINT, QC, Canada

External beam irradiation angle measurement using Cerenkov emission

In this study, we propose a novel approach designed to take advantage of the Cerenkov angular dependency to perform a direct measurement of an external beam radiation angle of incidence. The detector offers promising perspectives for external beam radiotherapy and brachytherapy applications.

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

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

Development of An Automated Routine for Finding the Precise Location of Scintillators Elements and Their Emission Spectrum in a Multi-Point Scintillation Detector

The goal of this study is to develop an approach allowing for calibration of multi-point scintillation detector (mPSD) using only the photon beam from a linear accelerator such that it doesn’t depend on the availability of other irradiation modalities (e.g. orthovoltage irradiators). This study also aims at determining an experimental method to validate the spatial position of the different scintillators within the mPSD.

2020 AAPM AM
B.Lessard (1,2), F.Larose (1,2), F.Berthiaume (1,2,3), S.Lambert-girard (1,2,3), F.Therriault-Proulx (3), L.Archambault (1,2) | Département de physique, génie physique et optique, et Centre de recherche sur le cancer, Université Laval, Québec, CA , CHU de Quebec – Universite Laval, QC, CA, MedScint, QC, CA

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