Examination of the dynamic range of Sm-doped glasses for high-dose and high-resolution dosimetric applications in microbeam radiation therapy at the Canadian synchrotron
| Autor: | George Belev, Brian Morrell, Shahrzad Vahedi, Andrew Edgar, Safa Kasap, Cyril Koughia, Chris Varoy, Go Okada, Tomasz W. Wysokinski, Dean Chapman |
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| Rok vydání: | 2013 |
| Předmět: |
Photoluminescence
Materials science business.industry Dynamic range Organic Chemistry Fluorophosphate glass Microbeam Atomic and Molecular Physics and Optics Synchrotron Electronic Optical and Magnetic Materials law.invention Inorganic Chemistry law Dosimetry Optoelectronics Irradiation Electrical and Electronic Engineering Physical and Theoretical Chemistry business Luminescence Spectroscopy Nuclear chemistry |
| Zdroj: | Optical Materials. 35:1976-1980 |
| ISSN: | 0925-3467 |
| Popis: | Microbeam Radiation Therapy (MRT) is a promising cancer treatment technique. During the treatment, a micro-planar lattice of narrow X-ray beams called a microbeam (each narrow X-ray beam is typically 20–100 μm wide separated by 100–400 μm) delivers a very large dose (>1000 Gy) onto a tumor. Sm3+-doped glasses that involve the reduction of the Sm-valency (Sm3+ → Sm2+) upon X-ray irradiation are one of the potential dosimetric detectors for this particular application. With this class of detectors, we use the extent of valency reduction as a measure of the delivered X-ray dose, and the response read out using a confocal microscopic technique via the Sm2+/Sm3+ photoluminescence. This method enables us to measure the dose distribution of the microbeam. In this paper, we show that both Sm3+-doped fluorophosphate and fluoroaluminate glasses exhibit a dynamic range for the conversion response from 1 to over 1000 Gy, which satisfies the dose range for MRT applications. The dynamic range depends on the concentration of Sm3+ dopants as well as the detector glass composition. Moreover, X-ray induced absorbance, photobleaching and thermally-stimulated luminescence (TL) measurements suggest that the hole trapping process during X-ray irradiation is a dominant factor for the valency conversion, and the accommodation of precursor POHCs in fluorophosphate glasses gives rise to an acceleration of the conversion process. |
| Databáze: | OpenAIRE |
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