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Title: Radioluminescence characterization of in situ x-ray nanodosimeters: Potential real-time monitors and modulators of external beam radiation therapy

Europium-doped yttrium oxide (Y{sub 2}O{sub 3}:Eu) has garnered considerable interest recently for its use as a highly efficient, red phosphor in a variety of lighting applications that include fluorescent lamps, plasma, and field emission display panels, light emitting diodes (LEDs), and lasers. In the present work, we describe the development of Y{sub 2}O{sub 3}:Eu nanoparticles for a very different application: in situ, in vivo x-ray dosimetry. Spectroscopic analyses of these nanoparticles during x-ray irradiation reveal surprisingly bright and stable radioluminescence at near-infrared wavelengths, with markedly linear response to changes in x-ray flux and energy. Monte Carlo modeling of incident flux and broadband, wide-field imaging of mouse phantoms bearing both Y{sub 2}O{sub 3}:Eu nanoparticles and calibrated LEDs of similar spectral emission demonstrated significant transmission of radioluminescence, in agreement with spectroscopic studies; with approximately 15 visible photons being generated for every x-ray photon incident. Unlike the dosimeters currently employed in clinical practice, these nanodosimeters can sample both dose and dose rate rapidly enough as to provide real-time feedback for x-ray based external beam radiotherapy (EBRT). The technique's use of remote sensing and absence of supporting structures enable perturbation-free dosing of the targeted region and complete sampling from any direction. With the conjugationmore » of pathology-targeting ligands onto their surfaces, these nanodosimeters offer a potential paradigm shift in the real-time monitoring and modulation of delivered dose in the EBRT of cancer in situ.« less
Authors:
; ;  [1] ; ; ;  [1] ;  [2] ;  [3]
  1. Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States)
  2. (China)
  3. Deaprtment of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States)
Publication Date:
OSTI Identifier:
22392035
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 20; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; 36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DOPED MATERIALS; DOSEMETERS; EUROPIUM; EXTERNAL BEAM RADIATION THERAPY; FIELD EMISSION; FLUORESCENT LAMPS; LIGHT EMITTING DIODES; MONTE CARLO METHOD; NANOPARTICLES; NEOPLASMS; PHANTOMS; PHOTONS; RADIOLUMINESCENCE; REMOTE SENSING; X RADIATION; X-RAY DOSIMETRY; YTTRIUM OXIDES