Samarium‐Doped Oxyfluoride Glass‐Ceramic as a New Fast Erasable Dosimetric Detector Material for Microbeam Radiation Cancer Therapy Applications at the Canadian Synchrotron. Issue 7 (16th April 2014)

• Record Type: Journal Article
• Authors: Okada, Go; Ueda, Jumpei; Tanabe, Setsuhisa; Belev, George; Wysokinski, Tomasz; Chapman, Dean; Tonchev, Dancho; Kasap, Safa; McKittrick, J.
• Is Part Of: Journal of the American Ceramic Society. Volume 97:Issue 7(2014)
• Page Start: 2147
• Page End: 2153
• Publication Date: 2014-04-16
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.12938
• Languages: English
• ISSNs: 0002-7820

Abstract

<abstract abstract-type="main" id="jace12938-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p>There is a special need to develop a dosimetry technique with a large‐dynamic range and high‐spatial resolution to characterize the microstructured X‐ray beams used in microbeam radiation therapy (MRT) for cancer. We report the synthesis and characterization of oxyfluoride glass‐ceramic (SiO<sub>2</sub>–Al<sub>2</sub>O<sub>3</sub>–CaF<sub>2</sub>–CaO–SmF<sub>3</sub>) plates, which contain trivalent‐samarium‐doped calcium fluoride (CaF<sub>2</sub>:Sm<sup>3+</sup>) nanocrystals, for use as a dosimetric detector material, particularly for MRT applications. Our approach utilizes the extent of Sm<sup>3+</sup>→Sm<sup>2+</sup> valence reduction caused by X‐ray irradiation as a probe of the X‐ray dose delivered; and confocal fluorescent microscopy is used to read out the distribution of valence reduction through the photoluminescence (PL) signal. Our study showed that the Sm<sup>3+</sup>→Sm<sup>2+</sup> valence reduction takes place in CaF<sub>2</sub> nanocrystals, but not in the glass matrix. The Sm<sup>2+</sup> shows PL emission predominantly due to the fast 4<italic>f</italic><sup>5</sup>5<italic>d</italic><sup>1</sup>→<sup>7</sup><italic>F</italic><sub>0</sub> transition, which allows us to read out the detector plate at a high scanning speed. Further, our experiments showed that the detection dose range reaches several thousands of grays, and X‐ray dose distribution is detected at a micrometer scale. In addition, the Sm<sup>2+</sup> signal can be erased either by heating the irradiated sample at a suitable high temperature or by exposing it to UV light; and the erased glass‐ceramic plate is reusable. The new Sm‐doped oxyfluoride glass‐ceramic with CaF<sub>2</sub> nanocrystals reported in this work shows potential for practical use in high‐dose and high‐resolution dosimetry for MRT.</p> </abstract>