Radiation damage and recovery of plastic scintillators under ultra-high dose rate 200 MeV electrons (VHEEs) at CERN CLEAR facility

4. FLASH-RT / UHDR, 9. Advanced Dosimetry, MeV Electron, Advanced Optical Dosimetry, Beam characterization, Custom Probe Development, Detector comparaison, Fundamental Research, Multi-point Dosimetry, Real-time Dosimetry Show more

The team investigates the radiation damage and recovery of plastic scintillators under ultra-high dose rate (UHDR) conditions using 200 MeV electrons at the CERN CLEAR facility (VHEEs). Their findings highlight the challenges of accurate dosimetry in UHDR radiotherapy and explores the potential of plastic scintillation detectors (PSDs) for research and clinical applications using this innovative beam conditions and modality.

HYPERSCINT, developed by Medscint, is uniquely positioned to address these challenges with its hyperspectral technology, enabling precise differentiation between scintillation and Cherenkov emissions. This innovation enhances dosimetry accuracy, making HYPERSCINT a valuable tool for advancing UHDR radiotherapy research and clinical implementation, including VHEEs.

Physics in Medicine & Biology
Cloé Giguère (1,2), Alexander Hart (3), Joseph Bateman (4), Pierre Korysko (4,5), Wilfrid Farabolini (5), Yoan LeChasseur (6), Magdalena Bazalova-Carter (3), Luc Beaulieu (1,2) | 1. Département de Physique, de Génie Physique et d’Optique et Centre de Recherche sur le Cancer, Université Laval – CANADA, 2. Département de Radio-Oncologie et Axe Oncologie du CRCHU de Québec, CHU de Québec, Université Laval – CANADA, 3. Department of Physics and Astronomy, University of Victoria – CANADA, 4. Department of Physics, University of Oxford – UK, 5. CERN – SWITZERLAND, 6. Medscint – CANADA

Field output correction factors using a fully characterized plastic scintillation detector (HYPERSCINT)

1. Small-Field Dosimetry, 7. Commissioning, 9. Advanced Dosimetry, MeV Electron, MV Photon, Beam characterization, Commissioning, Detector comparaison, Energy Dependency, Monte Carlo Simulations, Quality Assurance Show more

As small fields become increasingly important in radiation therapy, accurate dosimetry is essential for ensuring precise dose calculation and treatment optimization. Despite the availability of small volume detectors, small field dosimetry remains challenging. The new plastic scintillation detector (PSD) from the HYPERCINT RP-200 platform from Medscint offers a promising solution with minimal correction requirements for small field measurements.

This study focused on characterizing the field output correction factors of the PSD across a wide range of field sizes and demonstrating its potential for determining correction factors for other small field detectors. Monte Carlo simulations and experimental comparisons were used to assess the system’s performance. The PSD exhibited near-unity correction factors (1.002 to 0.999) across field sizes between 0.6×0.6 cm² and 30×30 cm², with an impressive total uncertainty of 0.5%.

The PSD is shown to be a highly accurate and reliable detector for small field dosimetry, and it can also be used to determine correction factors for other dosimeters with great precision.

MEDICAL PHYSICS (AAPM)
Luc Gingras (1,2), Yunuen Cervantes (1,2,3), Frederic Beaulieu (1,2), Magali Besnier (1,2), Benjamin Coté (4), Simon Lambert-Girard (4), Danahé LeBlanc (4), Yoan LeChasseur (4), François Therriault-Proulx (4), Luc Beaulieu (1,2,3), Louis Archambault (1,2,3) | 1. CHU de Québec–Université Laval, Québec – Canada, 2. Centre de recherche du CHU de Québec, Québec – Canada, 3. Université Laval, Québec – Canada, 4. Medscint, Québec – Canada

Radioluminescence-based fibre-optic dosimeters in radiotherapy: a review (incl. HYPERSCINT)

1. Small-Field Dosimetry, 2. Adaptive-RT (ex. MR-LINAC), 3. Treatment Plan (End-to-End) QA, 4. FLASH-RT / UHDR, 5. In Vivo Dosimetry, 6. Brachytherapy, 7. Commissioning, 8. Cherenkov Dosimetry, 9. Advanced Dosimetry, kV Photon, MeV Electron, MV Photon, Proton (and other Particules), Adaptive-RT, Advanced Optical Dosimetry, Custom Probe Development, Detector comparaison, Fundamental Research, LINAC Pulse Discrimination, Multi-point Dosimetry, Quality Assurance, Real-time Dosimetry Show more

In their comprehensive review, Veronese et al. examine the evolution and clinical application of radioluminescence-based fiber-optic dosimeters (FODs) in radiotherapy. These dosimeters have become essential tools in modern radiotherapy due to their capability for real-time, high-resolution dose measurements with minimal perturbation of the radiation field.

The authors discuss a wide range of scintillating materials, their properties, and dosimetric performance. They provide a thorough comparison of various solutions for addressing the stem-effect, a critical issue in fiber-optic dosimetry. Solutions reviewed include the hyperspectral approach (utilized by Medscint’s HYPERSCINT system), twin-fiber subtraction, optical filtering, dual-channel spectral discrimination, temporal gating, air-core light guides, and real-time Optically Stimulated Luminescence (rtOSL). Notably, the hyperspectral technology employed by HYPERSCINT represents a major advancement, effectively overcoming many limitations of other approaches by offering superior accuracy, simplified calibration procedures, and enhanced robustness, particularly valuable in complex clinical scenarios.

The review also emphasizes the growing adoption and diverse clinical applications of FODs, highlighting their significant role in improving treatment precision and patient safety. Clinical applications addressed in the review include small-field dosimetry, brachytherapy and in vivo dosimetry; advanced radiotherapy modalities such as intensity-modulated radiation therapy (IMRT), magnetic resonance-guided radiotherapy (MRgRT), hadron and proton therapies; and finally a special attention to MRI-Linac dosimetry and ultra-high dose rate (UHDR) or FLASH radiotherapy.

Radiation Measurements
Ivan Veronese (1), Claus E. Andersen (2), Enbang Li (3), Levi Madden (4), Alexandre M.C. Santos (5, 6, 7) | Department of Physics, University of Milan and National Institute for Nuclear Physics, Milano Unit, Italy, Department of Health Technology, Technical University of Denmark, Denmark, School of Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Australia, Northern Sydney Cancer Centre, Royal North Shore Hospital, Australia, Australian Bragg Centre for Proton Therapy and Research, Australia, Radiation Oncology, Central Adelaide Local Heath Network, Australia, School of Physics, Chemistry and Earth Sciences, The University of Adelaide, Australia

Comprehensive investigation of HYPERSCINT RP-FLASH scintillator for electron FLASH research

4. FLASH-RT / UHDR, MeV Electron, Detector comparaison, Quality Assurance, Rabiobiology Show more

This paper presents a comprehensive investigation of the HYPERSCINT RP-FLASH scintillator, designed for electron FLASH research. The study evaluates its performance in ultra-high dose rate (UHDR) electron beam dosimetry, with a focus on dose-rate independence, fast response times, and millisecond-resolved measurements. The scintillator system demonstrated high accuracy, minimal dependence on beam parameters, and effective calibration for clinical and research applications.

ARXIF Pre-publication
Lixiang Guo (1), Banghao Zhou (1), Yi-Chun Tsai (1), Kai Jiang (2), Viktor Iakovenko (2), Ken Kang-Hsin Wang (1) | 1. BIRTLab – University of Texas Southwestern Medical Center, Dallas, Texas, USA, 2. Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas, USA

Characterization of a novel time-resolved, real-time scintillation dosimetry system (HYPERSCINT RP-FLASH) for ultra-high dose rate radiation therapy applications

4. FLASH-RT / UHDR, MeV Electron, Beam characterization, Commissioning, Detector comparaison, Energy Dependency, LINAC Pulse Discrimination, Quality Assurance, Real-time Dosimetry Show more

This study evaluates a novel scintillation dosimetry solution developed by Medscint for ultra-high dose rate (UHDR) radiotherapy, the HYPERSCINT RP-FLASH. The system was tested on an UHDR electron beamline, demonstrating dose linearity and independence from dose rate (1.8–1341 Gy/s) and dose per pulse (0.005–7.68 Gy) within ±3% tolerance. The system accurately measured doses per pulse up to 120 Hz.

With daily calibrations and specific correction factors, the system provides real-time, millisecond-resolved dosimetric measurements for pulsed conventional and UHDR beams, showing promise for applications in FLASH-RT.

PREPRINT
Alexander Baikalov (1,2,3), Daline Tho (1), Kevin Liu (1,4), Stefan Bartzsch (2,3), Sam Beddar (1,4), Emil Schüler (1,4) | 1. University of Texas MD Anderson Cancer Center, Houston, TX – USA, 2. Technical University of Munich – Germany, 3. German Research Center for Environmental Health, Neuherberg – Germany, 4. The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX – USA

Characterization of a 0.8 mm³ Medscint Plastic Scintillator Detector System for Small Field Dosimetry

1. Small-Field Dosimetry, MeV Electron, Advanced Optical Dosimetry, Angular dependancy, Beam characterization, Detector comparaison, Energy Dependency, Quality Assurance Show more

The scintillator-based dosimetry system HYPERSCINT RP-200, coupled with a 0.8 mm³ plastic scintillator detector, demonstrated excellent dosimetric properties for small field radiation therapy, including good repeatability, dose linearity, and accuracy down to field sizes as small as 0.5 × 0.5 cm².

Physics in Medicine & Biology
Elena Timakova (1,2), Magdalena Bazalova-Carter (1) , Sergei Zavgorodni (2) | 1. University of Victoria, British Columbia, Canada, 2. BC Cancer Agency, Vancouver Island Centre, British Columbia, Canada

Performance of the HYPERSCINT scintillation dosimetry research platform for the 1.5 T MR-linac

2. Adaptive-RT (ex. MR-LINAC), 3. Treatment Plan (End-to-End) QA, MV Photon, Adaptive-RT, Angular dependancy, Detector comparaison, Energy Dependency, Quality Assurance, Real-time Dosimetry Show more

This study demonstrates the suitability of the HYPERSCINT PSD for accurate time- resolved dosimetry measurements in the 1.5 T MR-linac. The excellent performance during continuous MR scanning and during dynamic movement indicates the great potential of the detector to validate end-to-end workflows of online adaptive radiotherapy

PHYSICS IN MEDICINE & BIOLOGY
Prescilla Uijtewaal (1), Benjamin Côté (2), Thomas Foppen (1), J H Wilfred de Vries (1), Simon J Woodings (1), Pim T S Borman (1), Simon Lambert-Girard (2), François Therriault-Proulx (2), Bas W Raaymakers (1), Martin F Fast (1) | 1 – UMC Utrecht, Netherland, 2 – Medscint, Canada

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

5. In Vivo Dosimetry, 6. Brachytherapy, 9. Advanced Dosimetry, MV Photon, Advanced Optical Dosimetry, Detector comparaison, Fundamental Research, Real-time Dosimetry Show more

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

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

1. Small-Field Dosimetry, MV Photon, Commissioning, Detector comparaison, Monte Carlo Simulations, Quality Assurance Show more

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.

2022 AAPM ANNUAL MEETING
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

1. Small-Field Dosimetry, 7. Commissioning, MV Photon, Angular dependancy, Beam characterization, Commissioning, Detector comparaison, Energy Dependency, Quality Assurance Show more

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

2021 AAPM ANNUAL MEETING
J.Morin, JF.Cabana, M.Goulet, D.Theriault | CISSS – Chaudiere-Appalaches, Lévis, QC, CA