Development of End-to-End Preclinical Treatment Verification Procedures, Traceable to NPL Air Kerma Primary Standard

Dosimetry audits are an important tool to improve quality of reported results and to support standardization of preclinical radiation research. This work presents how the combination of passive and active detectors, such as the real-time HYPERSCINT scintillation dosimetry solution, with anatomically correct mouse phantoms are adequate for the development of End-to-End dosimetry audits for the independent verification of preclinical radiation treatments.

The traceability of the detectors’ calibration to primary standards strengthens the dosimetry chain in the validation of preclinical plans, and it is consistent with the current practice for dose traceability of clinical radiotherapy treatments. Their implementation at national and regional levels could lead to databases of anonymised records, which will positively impact the dissemination of best practices and sharing of validated results.

6th Conference on small animal precision image-guided radiotherapy
Ileana Silvestre Patallo (1), Rebecca Carter (2)(3), Andrew Nisbet (2), Anna Subiel (1), Giuseppe Schettino (1) | 1. National Physical Laboratory, UK, 2. University College London, UK, 3. Cancer Institut, UK

M-TAG: A Modular Teaching-Aid for Geant4

The article introduces M-TAG, a Geant4-based simulation tool for various physics applications, comparing it with similar tools like GATE, TOPAS, and GAMOS. M-TAG was employed to model and validate the HYPERSCINT detector’s performance. Additionally, it was used as an educational tool to teach a new user how to simulate and test the Hyperscint detector using Geant4.

Liam Carroll (1,2), Shirin A. Enger (1,2) | 1. Medical Physics Unit, Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada, 2. Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, H3T 1E2, 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

On the use of a single-fiber multipoint plastic scintillation detector for 192Ir high-dose-rate brachytherapy

The goal of this study was to prove the feasibility of using a single-fiber multipoint plastic scintillation detector as an in vivo verification tool during (192)Ir high-dose-rate brachytherapy treatments. The use of a multipoint plastic scintillation detector for high-dose-rate brachytherapy dosimetry is feasible. This detector shows great promise for development of in vivo applications for real-time verification of treatment delivery.

F.Therriault-Proulx, S.Beddar, L.Beaulieu | Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA

Review of plastic and liquid scintillation dosimetry for photon, electron, and proton therapy

While scintillation dosimetry has been around for decades, the need for a dosimeter tailored to the reality of modern radiation therapy-in particular a real-time, water-equivalent, energy-independent dosimeter with high spatial resolution-has generated renewed interest in scintillators over the last 10 years. This topical review is intended to provide the medical physics community with a wide overview of scintillation physics, related optical concepts, and applications of plastic scintillation dosimetry.

L Beaulieu (1,2), S Beddar (3,4) | 1- Département de physique, génie physique et optique, et Centre de recherche sur le cancer, Université Laval, Québec, CA , 2- Département de radio-oncologie et Axe Oncologie du CRCHU de Québec, QC, CA, 3- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA, 4- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA

FLASH Irradiation of Drosophila Melanogaster Using Low Energy X-Rays

To investigate the capability of low energy x-rays to elicit the FLASH effect, Drosophila melanogaster larvae were irradiated with ultrahigh dose-rate and conventional radiotherapy dose rates using an inexpensive x-ray tube system. Dosimetry was performed with plastic scintillators and radiochromic film, and the differential survival observed in this work suggests that continuous 120 kVp x-rays can induce a FLASH effect.

A.Hart, J.Dudzic, J.Eby, S.Perlman, M.Bazalova-Carter | University of Victoria, Victoria, BC ,CA

Orthovoltage to Monoenergetic Photon Beam Energy Correction Factor for HyperScint Scintillation Dosimeter

The scintillator dosimetry system is a small-field dosimeter with reported energy independence down to 100-keV. This work investigates the energy dependence of the scintillator between a monoenergetic photon source and polyenergetic orthovoltage beam.

B. Insley, D. Bartkoski, L. Che Fru, M. Salehpour | M.D. Anderson Cancer Center, Houston, TX

Characterization of an x‐ray tube‐based ultrahigh dose‐rate system for in vitro irradiations.

To present an x-ray tube system capable of in vitro ultrahigh dose-rate (UHDR) irradiation of small < 0.3 mm samples and to characterize it by means of a plastic scintillation detector (PSD).

Med Phys. 2021
D.Cecchi (1), F.Therriault-Proulx (2), S.Lambert-girard (2), A.Hart (1), A.Macdonald (1), M.Pfleger (1), M.Lenckowski (1), M.Bazalova-Carter (1) | Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, Canada, MedScint, QC, CA

Plastic and Lead-Doped Scintillators for Ultrahigh Dose-Rate Irradiations Delivered with An X-Ray Tube

To examine the capabilities of plastic scintillators of different compositions to accurately measure dose in high dose-rate dose irradiations delivered with an x-ray tube.

2021 AAPM AM
D.Cecchi (1), C.Gigeure (2), F.Larose (2), F.Therriault-Proulx (3), L.Beaulieu (2), M.Bazalova-Carter (1) | University of Victoria, Victoria, BC ,CA,, CHU de Quebec – Universite Laval, QC, CA, MedScint, QC, CA

Evaluation of scintillation detectors for ultrahigh dose-rate x-ray beam dosimetry

FLASH-Radiotherapy is an emerging ultrahigh dose rates radiotherapy technique, and animal studies have demonstrated the safety and efficacy of the technique in cancer treatment. A reliable real-time dosimeter system is crucial for the characterization of the so-called ‘FLASH-effect’, and an accurate beam delivery. This study aims to benchmark the performance of optical fiber inorganic scintillating detectors (ISDs) with plastic scintillating detectors (PSDs) for an ultrahigh dose-rate x-ray beam irradiation. Measurements includes : relative scintillator output, signal linearity with dose and dose rate, signal-to-noise ratio (SNR), signal stability and reliability.

The PSDs resulted in the highest reliability for a UHDR beam measurement with a CV of <0.1% while the Gd2O2S:Tb showed excellent repeatability (coefficient of variation (CV) <0.1%) compared to other detectors. All detectors showed good linearity with tube current (R2 < 0.975) and shutter exposure (R2 >0.999).

Proc Spie
Shahirah Shaharuddin (1), Alexander Hart (2), Magdalena Bazalova-Carter (2), Luc Beaulieu (3), Cloe Giguere (3), Christoph Kleefeld (1), Mark J. Foley (1) | 1. National University of Ireland, Galway (Ireland), 2. University of Victoria (Canada), 3 University Laval (Canada)