{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T01:44:15Z","timestamp":1784511855708,"version":"3.55.0"},"reference-count":54,"publisher":"Oxford University Press (OUP)","issue":"3","license":[{"start":{"date-parts":[[2022,2,1]],"date-time":"2022-02-01T00:00:00Z","timestamp":1643673600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"funder":[{"DOI":"10.13039\/501100003970","name":"Isfahan University of Medical Sciences","doi-asserted-by":"publisher","award":["398585"],"award-info":[{"award-number":["398585"]}],"id":[{"id":"10.13039\/501100003970","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2022,3,16]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>This study aimed to determine the neutron dose equivalent to the thyroid gland and eye lens in brain tumor radiation therapy with 15- and 18-MV three-dimensional conformal methods (3D-CRT). A Monte Carlo simulation was performed using the Monte Carlo N-particle transport code to calculate neutron fluence and ambient dose equivalent (H*(10)). Afterward, these parameters were measured using a model NRD roentgen equivalent in man (REM) neutron detector (Thermo Electron Corporation, USA) equipped with Eberline\u2019s ASP-2e rate meter. Finally, the organ neutron dose equivalent was obtained by applying depth corrections to the measured ambient dose equivalent at the distance of the organ center from the central beam axis. The ratio of the out-of-field photon dose equivalent, measured previously, to the neutron dose equivalent in the eye lens was high due to its proximity to the radiation field. In contrast, this ratio remained unexpectedly high in the thyroid gland that is far from the central beam axis (about 15\u00a0cm). The calculated neutron parameters agreed with the measurements. The present study findings indicate that external field photon dose is the main source of thyroid gland biological effects in radiotherapy of brain tumors. In addition, it is appropriate to apply the model NRD REM neutron detector for measuring neutron contamination from high-energy linear accelerators inside and outside the treatment field.<\/jats:p>","DOI":"10.1093\/rpd\/ncac001","type":"journal-article","created":{"date-parts":[[2022,1,10]],"date-time":"2022-01-10T20:10:35Z","timestamp":1641845435000},"page":"129-138","source":"Crossref","is-referenced-by-count":3,"title":["DETERMINATION OF THE NEUTRON CONTAMINATION DURING BRAIN RADIOTHERAPY USING A MODERATED-BORON TRIFLUORIDE DETECTOR AND THE MCNP MONTE CARLO CODE"],"prefix":"10.1093","volume":"198","author":[{"given":"Soheil","family":"Elmtalab","sequence":"first","affiliation":[{"name":"Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5999-0932","authenticated-orcid":false,"given":"Ahmad","family":"Shanei","sequence":"additional","affiliation":[{"name":"Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad Hossein","family":"Choopan Dastjerdi","sequence":"additional","affiliation":[{"name":"Reactor and Nuclear Safety research School, Nuclear Science and Technology Research Institute, Isfahan, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hrvoje","family":"Brki\u0107","sequence":"additional","affiliation":[{"name":"Department of biophysics and radiology, Faculty of Medicine, J. J. Strossmayer University of Osijek, Osijek, Croatia"},{"name":"Department of biophysics, biology and chemistry, Faculty of dental medicine and health, J. J. Strossmayer University of Osijek, Osijek, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6851-365X","authenticated-orcid":false,"given":"Iraj","family":"Abedi","sequence":"additional","affiliation":[{"name":"Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alireza","family":"Amouheidari","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, Isfahan Milad General Hospital, Isfahan, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2022,2,4]]},"reference":[{"issue":"1","key":"2022031605252233000_ref1","doi-asserted-by":"crossref","first-page":"7","DOI":"10.3322\/caac.21387","article-title":"Cancer statistics, 2017","volume":"67","author":"Siegel","year":"2017","journal-title":"CA Cancer J. Clin."},{"issue":"suppl_5","key":"2022031605252233000_ref2","doi-asserted-by":"crossref","first-page":"v1","DOI":"10.1093\/neuonc\/now207","article-title":"CBTRUS statistical report: primary brain and other central nervous system tumors diagnosed in the United States in 2009\u20132013","volume":"18","author":"Ostrom","year":"2016","journal-title":"Neuro-Oncology"},{"key":"2022031605252233000_ref3","doi-asserted-by":"crossref","first-page":"e315","DOI":"10.1016\/S1470-2045(17)30194-8","article-title":"European Association for neuro-oncology (EANO) guideline on the diagnosis and treatment of adult astrocytic and oligodendroglial gliomas","volume":"18","author":"Weller","year":"2017","journal-title":"Lancet Oncol."},{"issue":"3","key":"2022031605252233000_ref4","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1016\/j.pharmthera.2013.05.003","article-title":"Current status of local therapy in malignant gliomas\u2014a clinical review of three selected approaches","volume":"139","author":"Juratli","year":"2013","journal-title":"Pharmacol. Ther."},{"key":"2022031605252233000_ref5","author":"NCCN Clinical Practice Guidelines in Oncology: Anaplastic Gliomas\/Glioblastoma","year":"2018"},{"issue":"4","key":"2022031605252233000_ref6","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1118\/1.596779","article-title":"Higher energy: is it necessary, is it worth the cost for radiation oncology?","volume":"19","author":"Das","year":"1992","journal-title":"Med. Phys."},{"key":"2022031605252233000_ref7","volume-title":"AAPM Report No. 19. Neutron Measurements Around High Energy X-ray Radiotherapy Machines. A Report of Task Group 27","author":"Nath","year":"1986"},{"key":"2022031605252233000_ref8","volume-title":"NCRP Report 79","author":"Measurements","year":"1984"},{"key":"2022031605252233000_ref9","doi-asserted-by":"crossref","first-page":"681","DOI":"10.1007\/s10967-008-1504-y","article-title":"Measurements of the photonuclear neutron yield of 15 MV medical linear accelerator","volume":"278","author":"Alfuraih","year":"2008","journal-title":"J. Radioanal. Nucl. Chem."},{"issue":"1","key":"2022031605252233000_ref10","doi-asserted-by":"crossref","first-page":"1593","DOI":"10.1109\/TNS.1979.4330446","article-title":"Transport of accelerator produced neutrons in a concrete room","volume":"26","author":"McCall","year":"1979","journal-title":"IEEE Transact Nucl Sci"},{"issue":"3","key":"2022031605252233000_ref11","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/j.radmeas.2007.01.036","article-title":"Study of room-return neutrons","volume":"42","author":"Vega-Carrillo","year":"2007","journal-title":"Radiat. Meas."},{"issue":"8","key":"2022031605252233000_ref12","doi-asserted-by":"crossref","first-page":"1373","DOI":"10.1016\/j.radmeas.2007.06.006","article-title":"Spectrum of isotopic neutron sources inside concrete wall spherical cavities","volume":"42","author":"Ren\u00e9 Vega-Carrillo","year":"2007","journal-title":"Radiat. Meas."},{"issue":"28","key":"2022031605252233000_ref13","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.radmeas.2016.07.002","article-title":"The influence of field size and off-axis distance on photoneutron spectra of the 18 MV Siemens Oncor linear accelerator beam","volume":"93","author":"Brki\u0107","year":"2016","journal-title":"Radiat. Meas."},{"issue":"1","key":"2022031605252233000_ref14","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/j.apradiso.2004.05.072","article-title":"A study of neutron spectra from medical linear accelerators","volume":"62","author":"Facure","year":"2005","journal-title":"Appl. Radiat. Isot."},{"issue":"1","key":"2022031605252233000_ref15","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1016\/j.nima.2010.11.101","article-title":"Experimental characterization of the neutron spectra generated by a high-energy clinical LINAC","volume":"629","author":"Amgarou","year":"2011","journal-title":"NucL Instrum Methods Phys Res A."},{"issue":"1","key":"2022031605252233000_ref16","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1097\/00004032-200101000-00003","article-title":"Depth dose equivalent and effective energies of photoneutrons generated by 6-18 MV X-ray beams for radiotherapy","volume":"80","author":"d'Errico","year":"2001","journal-title":"Health Phys."},{"issue":"1","key":"2022031605252233000_ref17","first-page":"51","article-title":"ICRP publication 60: 1990 recommendations of the international commission on radiological protection","volume":"19","author":"Thorne","year":"1992","journal-title":"Ann. ICRP"},{"issue":"2","key":"2022031605252233000_ref18","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.radonc.2008.07.017","article-title":"Second cancers in children treated with modern radiotherapy techniques","volume":"89","author":"Schneider","year":"2008","journal-title":"Radiother. Oncol."},{"key":"2022031605252233000_ref19","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/j.apradiso.2016.05.006","article-title":"Neutron H*(10) estimation and measurements around 18MV linac","volume":"117","author":"Cer\u00f3n Ram\u00edrez","year":"2016","journal-title":"Appl. Radiat. Isot."},{"issue":"1","key":"2022031605252233000_ref20","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1007\/s10967-009-0337-7","article-title":"Neutron spectrum and doses in a 18 MV LINAC","volume":"283","author":"Vega-Carrillo","year":"2010","journal-title":"J. Radioanal. Nucl. Chem."},{"issue":"2","key":"2022031605252233000_ref21","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1007\/s10967-009-0363-5","article-title":"H*(10) and neutron spectra around linacs","volume":"283","author":"Vega-Carrillo","year":"2010","journal-title":"J. Radioanal. Nucl. Chem."},{"issue":"5","key":"2022031605252233000_ref22","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.rpor.2010.08.003","article-title":"A review on photoneutrons characteristics in radiation therapy with high-energy photon beams","volume":"15","author":"Naseri","year":"2010","journal-title":"Rep Pract Oncol Radiother."},{"key":"2022031605252233000_ref23","volume-title":"NCRP Report 151","author":"Dye","year":"2005"},{"issue":"2","key":"2022031605252233000_ref24","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/j.net.2015.11.003","article-title":"Measurement of photo neutron dose from an 18-MV medical linac using a foil activation method in view of radiation protection of patients","volume":"48","author":"Y\u00fccel","year":"2016","journal-title":"Nucl. Eng. Technol."},{"key":"2022031605252233000_ref25","volume-title":"Boron Trifluoride (BF3) Neutron Detectors","author":"Frame","year":"2011"},{"key":"2022031605252233000_ref26","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.apradiso.2018.12.007","article-title":"Essential considerations for accurate evaluation of photoneutron contamination in radiotherapy","volume":"145","author":"Karimi","year":"2019","journal-title":"Appl. Radiat. Isot."},{"issue":"3","key":"2022031605252233000_ref27","first-page":"231","article-title":"The influence of brass compensator thickness and field size on neutron contamination spectrum in 18MV Elekta SL 75\/25 medical linear accelerator with and without flattening filter: a Monte Carlo study","volume":"8","author":"Talebi","year":"2018","journal-title":"J Biomed Phys Engineer."},{"key":"2022031605252233000_ref28","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.apradiso.2018.04.022","article-title":"Effect of each component of a LINAC therapy head on neutron and photon spectra","volume":"139","author":"Khabaz","year":"2018","journal-title":"Appl. Radiat. Isot."},{"issue":"4","key":"2022031605252233000_ref29","doi-asserted-by":"crossref","first-page":"1204","DOI":"10.1016\/j.ijrobp.2004.12.091","article-title":"Out-of-field photon and neutron dose equivalents from step-and-shoot intensity-modulated radiation therapy","volume":"62","author":"Kry","year":"2005","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"issue":"2","key":"2022031605252233000_ref30","doi-asserted-by":"crossref","first-page":"360","DOI":"10.1118\/1.2140119","article-title":"Calculation of effective dose from measurements of secondary neutron spectra and scattered photon dose from dynamic MLC IMRT for, and beam energies","volume":"33","author":"Howell","year":"2006","journal-title":"Med. Phys."},{"key":"2022031605252233000_ref31","volume-title":"Limitation of Exposure to Ionizing Radiation. NCRP Report 116","author":"National Council on Radiation Protection and Measurements","year":"1993"},{"issue":"6","key":"2022031605252233000_ref32","doi-asserted-by":"crossref","first-page":"881","DOI":"10.1016\/j.amjsurg.2012.07.030","article-title":"Radiation treatment of patients with primary pediatric malignancies: risk of developing thyroid cancer as a secondary malignancy","volume":"204","author":"Rose","year":"2012","journal-title":"Am. J. Surg."},{"issue":"1","key":"2022031605252233000_ref33","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/j.ijrobp.2004.01.019","article-title":"Lens dose in MLC-based IMRT treatments of the head and neck","volume":"59","author":"Pawlicki","year":"2004","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"key":"2022031605252233000_ref34","doi-asserted-by":"crossref","DOI":"10.2172\/1134769","volume-title":"MCNP (TM) Release 6.1. 1 Beta: Creating and Testing the Code Distribution","author":"Cox","year":"2014"},{"issue":"3","key":"2022031605252233000_ref35","doi-asserted-by":"crossref","first-page":"172","DOI":"10.4103\/2228-7477.121010","article-title":"Monte Carlo simulation of siemens oncor linear accelerator with beamnrc and dosxyZnrc code","volume":"3","author":"Jabbari","year":"2013","journal-title":"J Med signals Sens."},{"issue":"2","key":"2022031605252233000_ref36","doi-asserted-by":"crossref","first-page":"217","DOI":"10.2298\/NTRP1802217B","article-title":"Influence of head cover on the neutron dose equivalent in Monte Carlo simulations of high energy medical linear accelerator","volume":"33","author":"Brki\u0107","year":"2018","journal-title":"Nucl Technol Radiat Prot."},{"issue":"3","key":"2022031605252233000_ref37","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1088\/0031-9155\/46\/3\/501","article-title":"Analysis of photoneutron spectra produced in medical accelerators","volume":"46","author":"Ongaro","year":"2001","journal-title":"Phys. Med. Biol."},{"issue":"12","key":"2022031605252233000_ref38","doi-asserted-by":"crossref","first-page":"2931","DOI":"10.1016\/j.nds.2006.11.001","article-title":"ENDF\/B-VII. 0: next generation evaluated nuclear data library for nuclear science and technology","volume":"107","author":"Chadwick","year":"2006","journal-title":"Nucl Data sheets."},{"key":"2022031605252233000_ref39","doi-asserted-by":"crossref","DOI":"10.2172\/4444548","volume-title":"MODIFIED-SPHERE NEUTRON DETECTOR","author":"Hankins","year":"1966"},{"key":"2022031605252233000_ref40","volume-title":"Radiation detection and measurement","author":"Knoll","year":"2010"},{"key":"2022031605252233000_ref41","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.nima.2019.03.008","article-title":"A neutron radiography beamline relying on the Isfahan miniature neutron source reactor","volume":"928","author":"Choopan Dastjerdi","year":"2019","journal-title":"Nucl Instrum Methods Phys Res A."},{"issue":"24","key":"2022031605252233000_ref42","doi-asserted-by":"crossref","first-page":"5921","DOI":"10.1088\/0031-9155\/50\/24\/011","article-title":"Monte Carlo study of Siemens PRIMUS photoneutron production","volume":"50","author":"Pena","year":"2005","journal-title":"Phys. Med. Biol."},{"issue":"4","key":"2022031605252233000_ref43","doi-asserted-by":"crossref","first-page":"498","DOI":"10.1118\/1.595543","article-title":"Neutron leakage measurements from a medical linear accelerator","volume":"11","author":"Palta","year":"1984","journal-title":"Med. Phys."},{"issue":"12","key":"2022031605252233000_ref44","doi-asserted-by":"crossref","first-page":"6789","DOI":"10.1118\/1.3658654","article-title":"Erratum: \u201csecondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators\u201d [Med. Phys. 36(9), 4027-4038 (2009)]","volume":"38","author":"Howell","year":"2011","journal-title":"Med. Phys."},{"issue":"3","key":"2022031605252233000_ref45","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1007\/s10967-015-3944-5","article-title":"Neutron spectrometry and determination of neutron contamination around the 15 MV Siemens Primus LINAC","volume":"304","author":"Mohammadi","year":"2015","journal-title":"J Radnal Nucl Chem."},{"issue":"1-4","key":"2022031605252233000_ref46","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1093\/rpd\/nch205","article-title":"Neutron spectra in a tissue equivalent phantom during photon radiotherapy treatment by LINACS","volume":"110","author":"Zanini","year":"2004","journal-title":"Radiat. Prot. Dosim."},{"issue":"3","key":"2022031605252233000_ref47","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1093\/rpd\/ncx015","article-title":"Out-of-field dose measurements for 3D conformal and intensity modulated radiotherapy of a paediatric brain tumour","volume":"176","author":"Majer","year":"2017","journal-title":"Radiat. Prot. Dosim."},{"issue":"1","key":"2022031605252233000_ref48","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1093\/rpd\/ncs134","article-title":"Estimation of the risk of secondary cancer in the thyroid gland and the breast outside the treated volume in patients undergoing brain, mediastinum and breast radiotherapy","volume":"154","author":"Vlachopoulou","year":"2013","journal-title":"Radiat. Prot. Dosim."},{"issue":"4","key":"2022031605252233000_ref49","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1093\/rpd\/ncs056","article-title":"Thyroid exposure to scattered radiation and associated second cancer risk from paediatric radiotherapy for extracranial tumours","volume":"152","author":"Mazonakis","year":"2012","journal-title":"Radiat. Prot. Dosim."},{"issue":"3","key":"2022031605252233000_ref50","doi-asserted-by":"crossref","first-page":"569","DOI":"10.52547\/ijrr.19.3.569","article-title":"Investigating the out-of-field doses and estimating the risk of secondary thyroid cancer in high-grade gliomas radiation therapy with modulated intensity and 3D-conformal: a phantom study","volume":"19","author":"Elmtalab","year":"2021","journal-title":"Int J Radiat Res."},{"key":"2022031605252233000_ref51","volume-title":"Practical radiation protection and applied radiobiology","author":"Dowd","year":"1999"},{"key":"2022031605252233000_ref52","first-page":"321","volume-title":"Phys Med","year":"2016"},{"issue":"4","key":"2022031605252233000_ref53","doi-asserted-by":"crossref","first-page":"1135","DOI":"10.1016\/j.ijrobp.2006.10.032","article-title":"Intensity modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy for highgrade gliomas: does IMRT increase the integral dose to normal brain?","volume":"67","author":"Hermanto","year":"2007","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."},{"issue":"3","key":"2022031605252233000_ref54","doi-asserted-by":"crossref","first-page":"892","DOI":"10.1016\/j.ijrobp.2005.05.067","article-title":"Intensitymodulated radiotherapy in high-grade gliomas: clinical and dosimetric results","volume":"64","author":"Narayana","year":"2006","journal-title":"Int. J. Radiat. Oncol. Biol. Phys."}],"container-title":["Radiation Protection Dosimetry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/rpd\/article-pdf\/198\/3\/129\/42899409\/ncac001.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/rpd\/article-pdf\/198\/3\/129\/42899409\/ncac001.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,3,16]],"date-time":"2022-03-16T05:28:22Z","timestamp":1647408502000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/rpd\/article\/198\/3\/129\/6522715"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,2]]},"references-count":54,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2022,2,4]]},"published-print":{"date-parts":[[2022,3,16]]}},"URL":"https:\/\/doi.org\/10.1093\/rpd\/ncac001","relation":{},"ISSN":["0144-8420","1742-3406"],"issn-type":[{"value":"0144-8420","type":"print"},{"value":"1742-3406","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2022,2]]},"published":{"date-parts":[[2022,2]]}}}