{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,13]],"date-time":"2025-12-13T14:21:19Z","timestamp":1765635679061,"version":"3.48.0"},"reference-count":38,"publisher":"IOP Publishing","issue":"3","license":[{"start":{"date-parts":[[2020,1,24]],"date-time":"2020-01-24T00:00:00Z","timestamp":1579824000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/publishingsupport.iopscience.iop.org\/iop-standard\/v1"},{"start":{"date-parts":[[2020,1,24]],"date-time":"2020-01-24T00:00:00Z","timestamp":1579824000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/iopscience.iop.org\/info\/page\/text-and-data-mining"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"crossref","award":["RGPIN\/4386-2017"],"award-info":[{"award-number":["RGPIN\/4386-2017"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["iopscience.iop.org"],"crossmark-restriction":false},"short-container-title":["Phys. Med. Biol."],"published-print":{"date-parts":[[2020,2,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Proton neutron gamma-x detection (PNGXD) is a novel imaging concept being investigated for tumor localization during proton therapy that uses secondary neutron interactions with a gadolinium contrast agent (GDCA) to produce characteristic photons within the 40\u2013200\u2009keV energy region. The purpose of this study is to experimentally investigate the feasibility of implementing this procedure by performing experimental measurements on a passive double scattering proton treatment unit. Five experimental measurements were performed with varying concentrations and irradiation conditions. Photon spectra were measured with a 25\u2009mm\n                    <jats:sup>2<\/jats:sup>\n                    , 1\u2009mm thick uncollimated X-123 CdTe spectrometer. For a 10.4 Gy administration on a 100\u2009ml volume phantom with 10\u2009mg g\n                    <jats:sup>\u22121<\/jats:sup>\n                    Gd solution placed in a water phantom, 1129\u2009\u2009\u00b1\u2009\u2009184 K-shell Gd counts were detected. For an administered dose of 21 Gy and the same Gd solution measured in air, resulted in 3296\u2009\u2009\u00b1\u2009\u2009256 counts. A total of 1094\u2009\u2009\u00b1\u2009\u2009171, 421\u2009\u2009\u00b1\u2009\u2009150 and 23\u2009\u2009\u00b1\u2009\u2009141 K-shell Gd counts were measured for Gd concentrations of 10\u2009mg g\n                    <jats:sup>\u22121<\/jats:sup>\n                    , 1\u2009mg g\n                    <jats:sup>\u22121<\/jats:sup>\n                    and 0\u2009mg g\n                    <jats:sup>\u22121<\/jats:sup>\n                    for 7 Gy dose in air. The signal to noise ratio for these five measurements were: 7, 15, 6, 3, and 0.2, respectively. The spectrum contained 43\u2009keV K\n                    <jats:sub>\n                      <jats:italic>\u03b1<\/jats:italic>\n                    <\/jats:sub>\n                    and 49\u2009keV K\n                    <jats:sub>\n                      <jats:italic>\u03b2<\/jats:italic>\n                    <\/jats:sub>\n                    peaks, however a small amount of 79.5 and 181.9\u2009keV prompt gamma rays were detected from gadolinium neutron capture. This discrepancy is due to a drop in the intrinsic detection efficiency of the CdTe spectrometer over this energy range. The measurements were compared with Monte-Carlo simulation to determine the contributions of Gd neutron capture from internal and external neutrons on a passive scattering proton therapy unit and to investigate the discrepancy in detected characteristic x-rays versus prompt gamma rays.\n                  <\/jats:p>","DOI":"10.1088\/1361-6560\/ab63b5","type":"journal-article","created":{"date-parts":[[2019,12,18]],"date-time":"2019-12-18T18:00:20Z","timestamp":1576692020000},"page":"035005","update-policy":"https:\/\/doi.org\/10.1088\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Investigating neutron activated contrast agent imaging for tumor localization in proton therapy: a feasibility study for proton neutron gamma-x detection (PNGXD)"],"prefix":"10.1088","volume":"65","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3776-3768","authenticated-orcid":false,"given":"Kurt W","family":"Van Delinder","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Crawford","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tiezhi","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7373-6858","authenticated-orcid":false,"given":"Rao","family":"Khan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8309-0088","authenticated-orcid":false,"given":"James L","family":"Gr\u00e4fe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"266","published-online":{"date-parts":[[2020,1,24]]},"reference":[{"key":"pmbab63b5bib001","doi-asserted-by":"publisher","first-page":"293","DOI":"10.1016\/S0167-8140(98)00049-8","type":"journal-article","article-title":"Secondary neutron and photon dose in proton therapy","volume":"48","author":"Agosteo","year":"1998","journal-title":"Radiother. 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All rights, including for text and data mining, AI training, and similar technologies, are reserved.","name":"copyright_information","label":"Copyright Information"},{"value":"2019-07-07","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2019-12-18","name":"date_accepted","label":"Date Accepted","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2020-01-24","name":"date_epub","label":"Online publication date","group":{"name":"publication_dates","label":"Publication dates"}}]}}