Evaluation of the HYPERSCINT scintillation dosimetry platform for small-field characterization of a Leksell Gamma Knife

The performance of the HYPERSCINT RP-200 with the 0.5mm x 0.5mm detector was evaluated for the characterization of small radiation fields administered using a Leksell Gamma Knife Perfexion radiosurgery device. Overall, our results show that the detector response was in close agreement with Gamma Knife Monte Carlo reference data and film measurements. Based on the obtained results, the plastic scintillation detector shows the potential for rapid validation of output factors and validation of film measurements as well its use in challenging small-field situations encountered with the Gamma Knife.

ISRS 2024 – New York
Mathieu GUILLOT (1), Patrick DELAGE (1), Vincent HUBERT-TREMBLAY (1), Francois THERRIAULT-PROULX (2), Danahé LEBLANC (2) | CHUS – Canada, Medscint – Canada

Performance characterization of a novel hybrid dosimetry insert for simultaneous spatial, temporal, and motion-included dosimetry for MR-linac

The increased treatment complexity and the motion-delivery interplay during stereotactic body radiotherapy (SBRT) on an MR-linac treatments require MR-compatible motion phantoms with time-resolved dosimeters to validate end-to-end workflows. This study demonstrates the excellent suitability of a the Medscint novel hybrid film-scintillators cassette for simultaneous multi-spatial, temporal, and motion-included dosimetry.

Prescilla Uijtewaal (1), Pim Borman (1), Benjamin Côté (2), Yoan LeChasseur (2), François Therriault-Proulx (2), Rocco Flores (3), Stephanie Smith (3), Grant Koenig (3), Bas Raaymakers (1), Martin Fast (1) | 1. Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands, 2. Medscint, Québec, Quebec, Canada, 3. Modus QA, London, Ontario, Canada

Use of a Commercial Plastic Scintillation Detector for Determination of Detector-Specific Small Field Output Correction Factors of Other Detectors

The goal of this work is to determine small field output correction factors of various detectors using the HYPERSCINT plastic scintillation detector as a reference and to compare values with current available data. The simple and well understood composition and geometry of the scintillation detector make it ideal to be used as a reference detector for the evaluation of field output correction factors. Field size dependent correction factors have been extracted for different detectors and show limited discrepancies with current available data. This may potentially be attributed to inter detector variability or other methodological uncertainties in published data.

M.Besnier (1), F.Beaulieu (1), F.Berthiaume (1,2), Y.Cervantes Espinosa (1), B.Côté (2), S.Lambert-girard (1,2), D.Leblanc (1,2), Y.Lechasseur (2), F.Therriault-Proulx (2), L.Archambault (1), L.Beaulieu (1), L.Gingras (1) | 1- CHU de Quebec – Universite Laval, QC, Canada, 2- MEDSCINT, QC, Canada

Comparison Between the HYPERSCINT RP200 Scintillation Detector and Other Small Field Detectors for 10MV FFF SRS Beam Modelling On a VersaHD Linear Accelerator

Plastic scintillation detectors (PSDs) have advantageous dosimetric properties, including small size and energy independence, which make them ideal candidates for small field dosimetry.

J.Morin, JF.Cabana, M.Goulet, D.Theriault | CISSS – Chaudiere-Appalaches, Lévis, QC, CA

Implementation and validation of beam current transformer for Mobetron ultra-high dose rate electron beam monitoring using multi-detector approach

To evaluate the performance of a custom beam current transformer (BCT) as a beam monitoring tool for the Mobetron electron radiation therapy system at ultra-high dose rates (UHDR) using a multi-detector comparison (plastic scintillators, ion chamber and film).

G.Famulari (1), K.Zerouali (1), J.Renaud (2), B.Muir (1), JF.Aubry (1), F.DeBlois (1), JF.Carrier (1) | 1 – Centre Hospitalier de l’Universite de Montreal (CHUM), Montreal, QC, CA, 2 – National Research Council Canada, Montreal, QC, CA

On the orientation independence of the HYPERSCINT scintillation dosimetry research platform in a MR-linac environment.

The purpose of this work was to characterize the HYPERSCINT scintillation dosimetry research platform in a MR-linac environment, particularly with respect to its orientation. This study shows that the HYPERSCINT scintillation dosimetry platform can be used regardless of its orientation in a magnetic field environment. Together with its linearity to dose and dose-rate, the detector shows great promises for development of dosimetry solutions dedicated to the MR-Linac environment.

B.Côté (1), B.Raaymakers (2), S.Woodings (2), P.Uijtewaal (2), W.de Vries (2), S.Lambert-girard (1), F.Therriault-Proulx (1), M.Fast (2) | Medscint, Canada (1), UMC Utrecht, Netherland (2)

Technical note: Characterization and practical applications of a novel plastic scintillator for online dosimetry for an ultrahigh dose rate (FLASH)

Although FLASH radiation therapy is a promising novel technique, the ultrahigh pulsed dose rates mean that experimental dosimetry is very challenging. The plastic scintillator shows a linear and reproducible response and is able to accurately measure the radiation absorbed dose delivered by 16-MeV electrons at UHPDR. The dose is measured accurately in real time with a greater level of precision than that achieved with a radiochromic film.

Med Phys. 2022
Y.Poirier (1,2), J.Xu (1), S.Mossahebi (1), F.Therriault-Proulx (3), A.Sawant (1) | 1- Department of Radiation Oncology, University of Maryland School of Medicine, Maryland, USA, 2- Department of Medical Physics, McGill University, Quebec, Canada, 3- MEDSCINT, Quebec, Canada

Brachytherapy Technique Commissioning Using the HYPERSCINT Plastic Scintillation Detector

Accurate dosimetry in brachytherapy is not an easy task, as most detectors exhibit volume averaging or energy dependence reducing their usability. Free from these limitations are plastic scintillation detectors, which makes them well suited for brachytherapy applications, either for in vivo dosimetry or commissioning. This work aims to determine if the HYPERSCINT scintillation dosimetry research platform can be used for brachytherapy dose measurement in the context of commissioning a new brachytherapy technique.

M.Goulet, N.Octave, P.Duguay-drouin | CISSS – Chaudiere-Appalaches, Lévis, QC, CA

Beam matching for small-field dosimetry applications using accelerator solenoid current and a miniature plastic scintillation detector.

The goal of this work is to determine the optimal accelerator solenoid current (ASOL) that minimizes the spread of measured small field output factor (OF) values between a series of machines. Small field OF measurements of 6 MV flattening filtered beams from 3 Varian TrueBeam linear accelerators were performed using a 1 mm diameter by 1 mm length plastic scintillation detector HYPERSCINT HS-RP200 research platform. In conclusion Small field dosimetry characteristics are highly sensitive to beam focal spot size. and the possibility to optimize accelerator focusing coil current to reduce OF and penumbra width spread enables new avenues in beam matching of series of machines, especially for SRS and SBRT techniques.

L.Gingras (1), F.Beaulieu (1), M.Besnier (1), B.Côté (2), D.Leblanc (2), L.Beaulieu (1), L.Archambault (1) | 1- CHU de Québec – Université Laval, QC, CA, 2- MEDSCINT, QC, 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).

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