Field output correction factors using a fully characterized plastic scintillation detector (HYPERSCINT RP-200)

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.

PREPRINT
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

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

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

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

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

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.

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

Characterization of a Novel Plastic Scintillator for Instant Real- Time Dosimetry in Electron FLASH-RT

Purpose was to characterize and validate the novel HYPERSCINT RP100 plastic dosimeter as a direct pulse counter and investigate its use as a real-time in-vivo dosimeter in FLASH-RT radiobiological experiments. In conclusions, the HYPERSCINT RP100 dosimeter accurately measured the delivered radiation absorbed dose under both characterization and biological experimental conditions, with a higher degree of reliability than conventional radiochromic film. Furthermore, its 500 Hz measurement frequency could directly and accurately measure the number of pulses delivered in real time. This shows its potential for real-time in-vivo dosimetry to verify accurate delivery during biological experiments and clinical treatments.

2021 COMP ANNUAL SCIENTIFIC MEETING
Y.Poirier (1), J.Xu (1), A.Ahmady (1), S.Mossahebi (1), H.Zhang (1), F.Therriault-Proulx (2), A.Sawant (1) | 1- University of Maryland School of Medicine, MD, USA , 2- McGill University, QC, Canada, 3- MEDSCINT, QC, Canada

Novel Plastic Scintillator for Online Dosimetry in Electron FLASH-RT

The accurate delivery of electrons at FLASH-RT dose rates in radiobiological experiments require new dosimeters that are capable of accurately measuring the radiation dose delivered at >0.55 Gy per pulse (>100 Gy/s) in real-time. The novel HYPERSCINT RP100 plastic dosimeter was able to accurately measure the delivered radiation absorbed dose under characterization and biological experimental conditions, with a higher degree of reliability than conventional radiochromic film. Furthermore, it was shown to directly and accurately measure the number of pulses delivered in real time. This shows potential for use as a real-time in-vivo dosimeter during biological experiments, as well as potential clinical applications.

2021 AAPM ANNUAL MEETING
Y.Poirier (1), J.Xu (1), A.Ahmady (1), S.Mossahebi (1), H.Zhang (1), F.Therriault-Proulx (2), A.Sawant (1) | 1- University of Maryland School of Medicine, Baltimore, MD, USA , 2- MEDSCINT, QC, CANADA

Investigation of the HyperscintTM Plastic Scintillation Dosimetry System Performance in a 15 MeV electron beam at FLASH dose rates

The performance of the HYPERSCINT plastic scintillation dosimetry system in a 15 MeV electron beam operating at FLASH dose rates was investigated. The linac produced a 15 MeV electron FLASH beam with an average dose rate of ~250 Gy/s and dose per pulse between 1 Gy and 1.7 Gy, at the level just above the multi-leaf collimator. The HYPERSCINT plastic scintillator detector system agreed with OSLDs within 3.5% for 10 to 20 pulse FLASH deliveries using the standard dose rate calibration for both dosimeters.

2021 COMP ANNUAL SCIENTIFIC MEETING
C.Mendez, P.Petric, T.Karan, C.Duzenli | BC Cancer, Vancouver, BC, CA

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

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.

PHYSICS IN MEDICINE & BIOLOGY
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