Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: II. Properties and measurements

The properties of a new scintillation detector system for use in dosimetry of high-energy beams in radiotherapy have been measured. The most important properties of these detectors are their hgh spatial resolution and their nearly water-equivalence.

A.S. Beddar, T.R. Mackie, F.H. Attix | Depanment of Medical Physics, University of Wisconsin Medical School, Madison, Wl, USA

Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: I. Physical characteristics and theoretical consideration

A minimally perturbing plastic scintillation detector has been developed for the dosimetry of high-energy beams in radiotherapy. The detector system consists of two identical parallel sets of radiation-resistant optical fibre bundles, each connected to independent photomultiplier tubes.

A.S. Beddar, T.R. Mackie, F.H. Attix | Depanment of Medical Physics, University of Wisconsin Medical School, Madison, Wl, USA

A method to correct for temperature dependence and measure simultaneously dose and temperature using a plastic scintillation detector

Plastic scintillation detectors work well for radiation dosimetry. However, they show some temperature dependence, and a priori knowledge of the temperature surrounding the plastic scintillation detectors is required to correct for this dependence.

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

Dosimetric Characterization of the ARIEL 10 MV X-Ray Ultrahigh Dose-Rate (FLASH) Irradiation Platform at TRIUMF

The purpose was to characterize the beam delivery capabilities and dose rates achievable on the new ultrahigh dose-rate 10MV x-ray irradiation platform at TRIUMF. Beam commissioning and dosimetry have been conducted on the ARIEL x-ray FLASH irradiation platform using film doses and scintillators. Measured dose rates support that the 10MV x-ray beam may be used as a UHDR source compatible with FLASH radiobiological experiments.

N.Esplen (1), L.Egoriti (2), T.Planche (3), A.Hart (1), B.Paley (3), C.Hoehr (3), A.Gottberg (3), M.Bazalova-Carter (1) | 1- University of Victoria, BC ,CA, 2- University of British Columbia, BC, CA, 3- TRIUMF, BC, CA

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.

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

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

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.

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