Development of a Novel Hybrid Scintillation-Cerenkov Detector for Simultaneous Dose and Irradiation Angle Measurements

8. Cherenkov Dosimetry, MV Photon, Advanced Optical Dosimetry, Custom Probe Development Show more

This study introduces a novel hybrid detector capable of simultaneous dose and direct irradiation angle measurements based on Cerenkov angular dependency.

2021 AAPM AM
E.Jean (1,2), S.Lambert-girard (3), F.Therriault-Proulx (3), L.Beaulieu (1) | CHU de Quebec – Universite Laval, QC, CA, CHAUR, Trois-Rivieres, QC, CA , MedScint, QC, CA

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

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

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)

Real-time dosimetry of ultrahigh dose-rate x-ray beams using scintillation detectors

4. FLASH-RT / UHDR, 5. In Vivo Dosimetry, 9. Advanced Dosimetry, kV Photon, Advanced Optical Dosimetry, Custom Probe Development, Detector comparaison, Fundamental Research, Real-time Dosimetry Show more

FLASH radiation therapy using an ultrahigh dose-rate beam is found to eradicate tumours whilst significantly reducing radiation-induced tissue toxicity. A real-time dosimetry system is required for the technique to be implemented clinically and for further preclinical studies. This study aimed to optimize the design of scintillating detectors using inorganic materials for real-time dosimetry in ultrahigh dose-rate radiation applications. Inorganic scintillator detectors were fabricated using phosphor-based scintillating materials (Gd2O2S:Tb, La2O2S:Tb, and La2O2S:Eu) coupled with optical fibers. The initial results in ultrahigh dose-rate x-ray irradiation showed excellent linearity with signal independent of the dose rate and dose delivered. A hyperspectral approach is adopted in this study to account for the stem effect that occurs within the high energy typically used in radiotherapy.

IEEE
Shahirah Shaharuddin (1), Alexander Hart (2), Daniel D. Cecchi (2), Magdalena Bazalova-Carter (2), Mark Foley (1) | 1. School of Physics, National University of Ireland Galway, Ireland, 2. Department of Physics & Astronomy, University of Victoria, Canada