Characterization of a multi-point scintillation dosimetry research platform for a low-field MR-Linac

Commissioning, In Vivo Dosimetry, MR-LINAC, MV Photon, Adaptive RT, Angular dependancy, Beam characterization, Commissioning, Quality Assurance, Real-time Dosimetry Show more

Plastic scintillation detectors (PSDs) are attractive for enhancing MRI-guided radiation therapy (MRgRT). A study evaluating the HYPERSCINT RP-200, a multi-probe PSD system, demonstrated excellent repeatability and minimal deviation in performance metrics such as detector response and percent depth dose (PDD). PSDs maintained consistent linearity across a broad range of monitor units and showcased high accuracy in gating experiments (ex. gating experiments where 400 cGy were delivered to isocenter : < 0.8 cGy variation for central axis measures and < 0.7 cGy for the gradient sampled region). These results highlight PSDs' huge potential in improving the precision and reliability of MRgRT, especially in complex real-time applications.

MEDICAL PHYSICS
Jennie Crosby (1), Chase Ruff (1), Ken Gregg (1), Jonathan Turcotte (2), Carri Glide-Hurst (1) | 1. Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin, USA, 2. Medscint, Québec, Quebec, Canada

Experimental dosimetric verification of the intra-fraction drift correction on the 1.5 T MR-linac

Commissioning, MR-LINAC, MV Photon, Adaptive RT, Commissioning, Multi-point, Quality Assurance, Real-time Dosimetry Show more

MRI-guided online adaptive treatments can improve tumor targeting by adjusting treatment plans in real-time based on cine MR-scans. And to correct the intra-fraction motion, Elekta AB introduced the intra-fraction drift correction (IDC) functionality for the 1.5 T Unity MR-linac.

The IDC is a valuable functionality for fast intra-fraction adaptations and this research experimentally verifies the geometric and dosimetric accuracy of the IDC process using film, scintillation, and diode dosimetry.

ESTRO 2024 Annual Congress
Madelon van den Dobbelsteen, Sara L. Hackett, Stijn Oolbekkink, Bram van Asselen, Prescilla Uijtewaal, Martin F. Fast, Bas W. Raaymakers | University Medical Center Utrecht, Radiotherapy, Utrecht, Netherlands

Evaluation of the HYPERSCINT scintillation dosimetry platform for small-field characterization of a Leksell GAMMA KNIFE

Commissioning, SMALL-FIELD, MV Photon, Beam characterization, Commissioning, Phantom QA, Quality Assurance Show more

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 – Sherbrooke, Canada, Medscint – Québec, Canada

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

Commissioning, MR-LINAC, Treatment Plan QA, MeV Electron, MV Photon, Adaptive RT, Commissioning, Multi-point, Phantom QA, Real-time Dosimetry Show more

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.

MEDICAL PHYSICS
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

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

Commissioning, SMALL-FIELD, 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

Characterization of the HYPERSCINT Dosimetry System for Real-Time Dosimetry Measurements with the Varian TrueBeamLinac

Commissioning, MV Photon, Adaptive RT, Quality Assurance, Real-time Dosimetry Show more

Plastic scintillator/optical fibre dosimetry systems are advantageous due to their near water equivalence, waterproof construction, linear dose response, and good spatial resolution due to their small size. The nanosecond decay times of plastic scintillators enable the possibility of real-time dosimetry. We tested the new HYPERSCINT fibre detector system to determine if, in addition to the expected dose and field size responses, this system can provide real-time dose information. The HYPERSCINT system is suitable after appropriate calibration to be used to measure relative dose delivered in cGy as well as indicate changing dose conditions within 0.3 seconds.

2020 AAPM AM
C.Penner (1,2), C.Hoehr (2), C.Mendez (1), C.Duzenli (1) | BC Cancer, Vancouver, BC, CA, TRIUMF, Vancouver, BC, CA

Brachytherapy Technique Commissioning Using the HYPERSCINT Plastic Scintillation Detector

Brachytherapy, Commissioning, In Vivo Dosimetry, kV Photon, Commissioning, Detector comparaison, Quality Assurance Show more

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.

2020 AAPM ANNUAL MEETING
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.

Commissioning, SMALL-FIELD, MV Photon, Commissioning, Quality Assurance Show more

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.

2022 COMP ANNUAL SCIENTIFIC MEETING
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

Commissioning, FLASH-RT, MeV Electron, Commissioning, Detector comparaison, Quality Assurance Show more

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).

2022 AAPM ANNUAL MEETING
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