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

High-throughput, low-cost FLASH: irradiation of Drosophila melanogaster with low-Energy X-rays using time structures spanning ConvDR and UHDR

4. FLASH-RT / UHDR, 5. In Vivo Dosimetry, kV Photon, Fundamental Research, Rabiobiology, Real-time Dosimetry Show more

This article explores the potential of using low-energy X-rays to deliver ultrahigh dose-rate (UHDR) FLASH radiotherapy using Drosophila melanogaster as a model. For this they have compared the effects of UHDR (210 Gy/s) and conventional dose rates (0.2–0.4 Gy/s) on the eclosion and lifespan of fly larvae. The results showed that larvae treated with UHDR had higher survival rates and longer lifespans, particularly at intermediate doses, indicating a normal tissue-sparing FLASH effect.

The Medscint scintillation dosimetry detector was used to measure the response to X-rays at a very high sampling rate to confirm the time structure of the delivered radiation (i.e. the pulse width and inter-pulse spacing). Along with film measurements, they also confirmed that the doses delivered with UHDR and CONV agreed within 0.1%.

Journal of Radiation Research
Alexander Hart (1), Jan P Dudzic (1), Jameson W Clarke (1), Jonathan Eby (2), Steve J Perlman (1), Magdalena Bazalova-Carter (1) | 1. University of Victoria, BC – CANADA, 2. University of Toronto, ON – CANADA

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

1. Small-Field Dosimetry, 3. Treatment Plan (End-to-End) QA, 5. In Vivo Dosimetry, kV Photon, Adaptive-RT, Fundamental Research, Phantom QA, Quality Assurance, Rabiobiology, Real-time Dosimetry Show more

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

9. Advanced Dosimetry, kV Photon, Monte Carlo Simulations Show more

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.

Heliyon
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

5. In Vivo Dosimetry, 6. Brachytherapy, 7. Commissioning, 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

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

5. In Vivo Dosimetry, 6. Brachytherapy, 9. Advanced Dosimetry, kV Photon, Fundamental Research, Real-time Dosimetry Show more

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.

MEDICAL PHYSICS
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

9. Advanced Dosimetry, kV Photon, MeV Electron, MV Photon, Proton (and other Particules), Fundamental Research Show more

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.

PHYSICS IN MEDICINE & BIOLOGY
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

4. FLASH-RT / UHDR, 5. In Vivo Dosimetry, kV Photon, Rabiobiology Show more

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.

2022 AAPM ANNUAL MEETING
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

9. Advanced Dosimetry, kV Photon, Energy Dependency, Monte Carlo Simulations Show more

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.

2022 AAPM ANNUAL MEETING
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.

4. FLASH-RT / UHDR, kV Photon, Rabiobiology, Real-time Dosimetry Show more

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