Development and first implementation of a novel multi-modality cardiac motion and dosimetry phantom for radiotherapy applications

Magnetic resonance guided radiation therapy (MRgRT) for real-time gating around the heart for treating ventricular tachycardia (VT) are rapidly advancing. A novel, multi-modality modular heart phantom was developed and utilized in gated radiotherapy experiments on a 0.35 T MR-linac. This phantom can simulate cardiac, cardio-respiratory, and respiratory motions, and perform dosimetric evaluations using ionization chamber and plastic scintillation detectors (PSD from MEDSCINT) configurations.

Due to their small sensitive volumes, time-resolved PSDs are effective for low-amplitude/high-frequency movements and multi-point data acquisition, enhancing dosimetric capabilities. This advancement in VT planning and delivery illustrates the phantom’s potential to meet the growing demands of cardiac applications in radiotherapy.

MEDICAL PHYSICS
Kenneth W. Gregg (1,2), Chase Ruff (1,2), Grant Koenig (3), Kalin I. Penev (3), Andrew Shepard (1), Grace Kreissler (4), Margo Amatuzio (4), Cameron Owens (4), Prashant Nagpal (5), Carri K. Glide-Hurst (1,2) | 1. Department of Human Oncology, University of Wisconsin–Madison, Madison, Wisconsin, USA, 2. Department of Medical Physics, University of Wisconsin–Madison, Madison, Wisconsin, USA, 3. Modus Medical Devices, Inc. (IBA QUASAR),London, Ontario, Canada, 4. Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin, USA, 5. Department of Radiology, University of Wisconsin–Madison, Madison, Wisconsin, USA

MLC tracking and dose accumulation validation on the MR-linac using a real-time deformable dosimeter

Online MRI on the MR-linac captures detailed anatomical movements, improving real-time radiotherapy adaptations. However, the lack of a suitable MRI-compatible phantom hinders workflow validation. This study introduces a deformable phantom with integrated real-time scintillation dosimeters, validating accuracy in MLC tracking and dose accumulation using the ELEKTA Unity MR-linac.

This study demonstrates the vast potential of this novel prototype deformable phantom with integrated PSDs for real-time dosimetry measurements on an MR-linac.

2024 ESTRO Annual Congress
Madelon van den Dobbelsteen (1), Pim T.S. Borman (1), Laurie J.M. de Vries (1), Sara L. Hackett (1), Kalin Penev (1), Rocco Flores (2), Stephanie Smith (2), Yoan LeChasseur (3), Simon Lambert-Girard (3), Benjamin Côté (3) , Peter L. Woodhead (1)(4), Lando S. Bosma (1), Cornel Zachiu (1), Bas W. Raaymakers (1), Martin F. Fast (1) | 1 University Medical Center Utrecht, Radiotherapy, Utrecht, Netherlands., 2 IBA QUASAR, Modus Medical Devices Inc. London ON, Canada. , 3 Medscint, -, Quebec City, Canada. , 4 Elekta AB, -, Stockholm, Sweden.

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

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

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.

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

Plastic scintillation detectors: real-time dosimetry in the MR-Linac environment.

Optical innovation meets clinical translation : in the vanguard of adaptive MR/RT research effort, the UMC Utrecht research team works with plastic scintillation detectors to bring MR-Linac treatment to the next level.

PHYSICS WORLD
| UMC Utrecht, Medscint

Development of a novel multi-point plastic scintillation detector with a single optical transmission line for radiation dose measurement

The goal of this study was to develop a novel multi-point plastic scintillation detector capable of measuring the dose accurately at multiple positions simultaneously using a single optical transmission line. This study demonstrates the practical feasibility of multi-point plastic scintillation detector. This type of detector could be very useful for pre-treatment quality assurance applications as well as an accurate tool for real-time in vivo dosimetry.

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

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.

2022 AAPM ANNUAL MEETING
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

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

Dosimetric Characterization of the HYPERSCINT Scintillation Dosimetry Research Platform for Multipoint Applications

Multipoint detectors are very interesting toward developing new phantoms and making measurements in constrained space. This study aims at assessing the performance of the HYPERSCINT dosimetry research platform (Medscint inc., Québec, Canada) with a high spatial resolution 3-point plastic scintillation detector for application to high energy photon beam dosimetry.

2020 AAPM AM
E.Jean, F.Therriault-Proulx, L.Beaulieu | CHU de Quebec – Universite Laval, QC, CA, Medscint, QC, CA , Centre Hospitalier Univ de Québec, Québec, QC, CA