Fiber‐optic detector for real time dosimetry of a micro‐planar x‐ray beam

Belley, Matthew D.; Stanton, Ian N.; Hadsell, M; Ger, Rachel B.; Langloss, Brian W.; Lu, Jianping; Zhou, Otto; Chang, S; Therien, Michael J.; Yoshizumi, Terry T.

doi:10.1118/1.4915078

Cited by 18 publications

(18 citation statements)

References 36 publications

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“…Furthermore, Y 2 O 3 crystals activated with Eu and Li emit stronger scintillation (Shin et al 2005, Stanton et al 2014, Bae et al 2007) and photoluminescence (Sun et al 2001) than do crystals activated with Eu ions alone. In a study using external-beam radiation sources, Belley et al (2015b) employed 11-μm-thick pellets of about 50-nm-sized Y 2 O 3 :Eu,Li crystals (Stanton et al 2014) coupled with a fiber-optic cable. The importance to compare the light yield and other luminescence properties of nanometer-sized crystals and crystals co-doped with Eu and Li with the properties of commercial Eu-activated phosphors, has been stressed by Kawahara et al (2006).…”

Section: Discussionmentioning

confidence: 99%

“…These Eu-activated scintillators have been studied for use with various external-beam radiation sources (Martinez et al 2015, Molina et al 2013, 2012, Souris et al 2014, McCarthy et al 2014), but their suitability for use with 192 Ir BT sources has yet to be established. Investigators have studied detectors using nanometer-sized Y 2 O 3 crystals co-doped with Eu and Li (Stanton et al 2014) for external-beam sources (Belley et al 2015b) and for 192 Ir HDR BT (Belley et al 2015a). To our knowledge, the light yield and other luminescence properties of crystals co-doped with Eu and Li have not been compared with those of commercial Eu-activated phosphors.…”

Section: Introductionmentioning

confidence: 99%

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Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Kertzscher

Beddar

2017

Phys. Med. Biol.

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The availability of real-time treatment verification during high-dose-rate (HDR) brachytherapy is currently limited. Therefore, we studied the luminescence properties of the widely commercially available scintillators using the inorganic materials Eu-activated phosphors Y2O3:Eu, YVO4:Eu, Y2O2S:Eu, and Gd2O2S:Eu to determine whether they could be used to accurately and precisely verify HDR brachytherapy doses in real time. The suitability for HDR brachytherapy of inorganic scintillation detectors (ISDs) based on the 4 Eu-activated phosphors in powder form was determined based on experiments with a 192Ir HDR brachytherapy source. The scintillation intensities of the phosphors were 16 to 134 times greater than that of the commonly used organic plastic scintillator BCF-12. High signal intensities were achieved with an optimized packing density of the phosphor mixture and with a shortened fiber-optic cable. The influence of contaminating Cerenkov and fluorescence light induced in the fiber-optic cable (stem signal) was adequately suppressed by inserting between the fiber-optic cable and the photodetector a 25-nm band-pass filter centered at the emission peak. The spurious photoluminescence signal induced by the stem signal was suppressed by placing a long-pass filter between the scintillation detector volume and the fiber-optic cable. The time-dependent luminescence properties of the phosphors were quantified by measuring the non-constant scintillation during irradiation and the afterglow after the brachytherapy source had retracted. We demonstrated that a mixture of Y2O3:Eu and YVO4:Eu suppressed the time-dependence of the ISDs and that the time-dependence of Y2O2S:Eu and Gd2O2S:Eu introduced large measurement inaccuracies. We conclude that ISDs based on a mixture of Y2O3:Eu and YVO4:Eu are promising candidates for accurate and precise real-time verification technology for HDR BT that is cost effective and straightforward to manufacture. Widespread dissemination of this technology could lead to an improved understanding of error types and frequencies during BT and to improved patient safety during treatment.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Kertzscher

Beddar

2017

Phys. Med. Biol.

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“…SCDDs and SSDs boast a practical resolution for microbeam dosimetry, but lack water equivalence [25] [26] [27]. A crystal scintillator dosimeter has been demonstrated, but this device also lacks water equivalence [28]. We believe a photonic dosimeter has the potential to be applied to MRT QA, as the plastic scintillator dosimeters are water equivalent, have the spatial resolution to resolve microbeams, and can provide real time dosimetry.…”

Section: Introductionmentioning

confidence: 99%

Recent advances in photonic dosimeters for medical radiation therapy

Archer

2018

Front. Optoelectron.

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Radiation therapy, which uses X-rays to destroy or injure cancer cells, has become one of the most important modalities to treat the primary cancer or advanced cancer. High resolution, water equivalent and passive X-ray dosimeters are highly desirable for developing quality assurance (QA) systems for novel cancer therapy like microbeam radiation therapy (MRT) which is currently under development. Here we present the latest developments of high spatial resolution scintillator based photonic dosimeters, and their applications to clinical external radiation beam therapies: specifically high energy linear accelerator (LINAC) photon beams and low energy synchrotron photon beams. We have developed optical fiber dosimeters with spatial resolutions ranging from 50 to 500 mm and tested them with LINAC beams and synchrotron microbeams. For LINAC beams, the fiberoptic probes were exposed to a 6 MV, 10 cm by 10 cm Xray field and, the beam profiles as well as the depth dose profiles were measured at a source-tosurface distance (SSD) of 100 cm. We have also demonstrated the possibility for temporally separating Cherenkov light from the pulsed LINAC scintillation signals. Using the 50 mm fiber probes, we have successfully resolved the microstructures of the microbeams generated by the imaging and medical beamline (IMBL) at the Australian Synchrotron and measured the peak-to-valley dose ratios (PVDRs). In this paper, we summarize the results we have achieved so far, and discuss the possible solutions to the issues and challenges we have faced, also highlight the future work to further enhance the performances of the photonic dosimeters.

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“…A crystal scintillator dosimeter, which demonstrated a resolution of 100 μ m has been described by Belley et al . 18 . However as the scintillator is crystalline, it is not water-equivalent and so must be calibrated against an ionisation chamber, is only valid at calibrated energies, when the crystal is completely inside the microbeam.…”

Section: Introductionmentioning

confidence: 99%

X-ray microbeam measurements with a high resolution scintillator fibre-optic dosimeter

Archer

Petasecca

et al. 2017

Sci Rep

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Synchrotron microbeam radiation therapy is a novel external beam therapy under investigation, that uses highly brilliant synchrotron x-rays in microbeams 50 μm width, with separation of 400 μm, as implemented here. Due to the fine spatial fractionation dosimetry of these beams is a challenging and complicated problem. In this proof-of-concept work, we present a fibre optic dosimeter that uses plastic scintillator as the radiation conversion material. We claim an ideal one-dimensional resolution of 50 μm. Using plastic scintillator and fibre optic makes this dosimeter water-equivalent, a very desirable dosimetric property. The dosimeter was tested at the Australian Synchrotron, on the Imaging and Medical Beam-Line. The individual microbeams were able to be resolved and the peak-to-valley dose ratio and the full width at half maximum of the microbeams was measured. These results are compared to a semiconductor strip detector of the same spatial resolution. A percent depth dose was measured and compared to data acquired by an ionisation chamber. The results presented demonstrate significant steps towards the development of an optical dosimeter with the potential to be applied in quality assurance of microbeam radiation therapy, which is vital if clinical trials are to be performed on human patients.

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Fiber‐optic detector for real time dosimetry of a micro‐planar x‐ray beam

Cited by 18 publications

References 36 publications

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Recent advances in photonic dosimeters for medical radiation therapy

X-ray microbeam measurements with a high resolution scintillator fibre-optic dosimeter

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Fiber‐optic detector for real time dosimetry of a micro‐planar x‐ray beam

Cited by 18 publications

References 36 publications

Inorganic scintillation detectors based on Eu-activated phosphors for192Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for192Ir brachytherapy

Recent advances in photonic dosimeters for medical radiation therapy

X-ray microbeam measurements with a high resolution scintillator fibre-optic dosimeter

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Product

Resources

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Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy

Inorganic scintillation detectors based on Eu-activated phosphors for¹⁹²Ir brachytherapy