{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T14:19:09Z","timestamp":1788272349278,"version":"build-2803163510"},"reference-count":33,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T00:00:00Z","timestamp":1786320000000},"content-version":"vor","delay-in-days":9,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:00:00Z","timestamp":1785542400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100006559","name":"University of Tsukuba","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100006559","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Medical Physics"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Boron neutron capture therapy (BNCT) has emerged as a promising cell\u2010selective clinical treatment for recurrent glioblastoma as well as head and neck cancers. In recent years, BNCT has been implemented in several hospitals using accelerator\u2010based neutron sources. However, direct online measurement of the incident neutron beam intensity during clinical BNCT remains a major challenge. Neutron dosimetry is typically inferred from the accumulated electric charge of the incident proton beam delivered to the beryllium neutron\u2010production\u00a0target.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>To improve the reliability of neutron beam control, it is essential to implement an online neutron\u2010monitoring system that complements proton beam current measurements. Such a system enables precise real\u2010time regulation of the neutron dose delivered to patients. In this study, we developed a new online neutron\u2010beam monitoring technique capable of measuring the neutron beam intensity in real\u00a0time.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Reliable monitoring of neutron intensity at the patient position was achieved by detecting fast neutrons. The fast\u2010neutron detector consisted of a silicon diode coupled with a high\u2010density polyethylene neutron converter. The spatial distribution of neutrons was evaluated using Monte Carlo simulations to determine the optimal placement of the neutron beam monitor. The proposed method was validated through gold\u2010activation analysis, cell irradiation experiments, and accelerator\u00a0tuning.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Online neutron\u2010beam monitoring was successfully achieved by detecting fast neutrons at the end of the vacuum beam duct, where neutrons propagate directly without traversing radiation shielding. The neutron counting rate increased immediately at the onset of proton\u2010beam irradiation and decreased upon its termination, exhibiting periodic fluctuations throughout the irradiation period. These fluctuations did not significantly affect the integrated neutron counts, as they were averaged over a typical BNCT irradiation time of approximately 30 min. The fast\u2010neutron detector produced a mean counting rate of 124.6 counts per mC of incident proton\u2010beam charge, with a relative standard deviation of 1.2%, and yielded a neutron\u2010calibration factor of  per monitor unit. The neutron counting rates remained consistent even when different irradiation phantoms were placed at the patient\u00a0position.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>The online neutron\u2010beam monitoring technique using a fast\u2010neutron detector demonstrated high reproducibility, as the neutron counting rates remained stable regardless of the irradiation phantom placed\u00a0downstream.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/mp.70629","type":"journal-article","created":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T14:30:11Z","timestamp":1786372211000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Development of an online neutron beam monitoring method for accelerator\u2010based BNCT using an 8\u2010MeV proton\u2010beryllium source"],"prefix":"10.1002","volume":"53","author":[{"given":"Masashi","family":"Takada","sequence":"first","affiliation":[{"name":"National Defense Academy of Japan Yokosuka Kanagawa Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiroaki","family":"Kumada","sequence":"additional","affiliation":[{"name":"Proton Medical Research Center, Institute of Medicine University of Tsukuba Tsukuba Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masashi","family":"Oyauchi","sequence":"additional","affiliation":[{"name":"National Defense Academy of Japan Yokosuka Kanagawa Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susumu","family":"Tanaka","sequence":"additional","affiliation":[{"name":"Proton Medical Research Center, Institute of Medicine University of Tsukuba Tsukuba Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tomoya","family":"Nunomiya","sequence":"additional","affiliation":[{"name":"Industry Business Group Fuji Electric Co., Ltd. Hino Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Toshiyuki","family":"Ohba","sequence":"additional","affiliation":[{"name":"NAT Co. Hitachinaka\u2010shi Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akihiko","family":"Masuda","sequence":"additional","affiliation":[{"name":"National Metrology Institute of Japan National Institute of Advanced Industrial Science and Technology Tsukuba Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tetsuro","family":"Matsumoto","sequence":"additional","affiliation":[{"name":"National Metrology Institute of Japan National Institute of Advanced Industrial Science and Technology Tsukuba Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,8,10]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1093\/noajnl\/vdab067"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2020.11.001"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1093\/jjco\/hyac004"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.apradiso.2019.108961"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2024.110607"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s43673-022-00063-2"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1089\/cbr.2022.0059"},{"key":"e_1_2_8_9_1","volume-title":"Advances in boron neutron capture therapy","author":"International Atomic Energy Agency","year":"2023"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.17480"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.17699"},{"key":"e_1_2_8_12_1","doi-asserted-by":"publisher","DOI":"10.1109\/TNS.2023.3249823"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.nima.2024.169352"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radmeas.2024.107070"},{"key":"e_1_2_8_15_1","doi-asserted-by":"publisher","DOI":"10.1140\/epjti\/s40485-023-00105-5"},{"key":"e_1_2_8_16_1","article-title":"Boron neutron capture therapy for recurrent glioblastoma multiforme: imaging evaluation of a case with long\u2010term local control and survival","volume":"15","author":"Shimizu S","year":"2023","journal-title":"Cureus"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.apradiso.2025.112152"},{"key":"e_1_2_8_18_1","doi-asserted-by":"publisher","DOI":"10.1585\/pfr.13.2406006"},{"key":"e_1_2_8_19_1","doi-asserted-by":"publisher","DOI":"10.1080\/00223131.2017.1419890"},{"key":"e_1_2_8_20_1","doi-asserted-by":"publisher","DOI":"10.1080\/18811248.2011.9711675"},{"key":"e_1_2_8_21_1","first-page":"41","article-title":"Overview of JENDL\u20104.0\/HE and benchmark calculation. in","volume":"2016","author":"Kunieda S","year":"2016","journal-title":"JAEA\u2010Conf"},{"key":"e_1_2_8_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.nima.2008.10.019"},{"key":"e_1_2_8_23_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0168-9002(98)00888-2"},{"key":"e_1_2_8_24_1","doi-asserted-by":"publisher","DOI":"10.1080\/00223131.2008.10875815"},{"key":"e_1_2_8_25_1","doi-asserted-by":"publisher","DOI":"10.1109\/TNS.2008.2010858"},{"key":"e_1_2_8_26_1","doi-asserted-by":"publisher","DOI":"10.1093\/rpd\/ncu008"},{"key":"e_1_2_8_27_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radmeas.2013.01.024"},{"key":"e_1_2_8_28_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.4982036"},{"key":"e_1_2_8_29_1","unstructured":"BergerM CourseyJ ZuckerM ChangJ.ESTAR PSTAR and ASTAR: computer programs for calculating stopping\u2010Power and range tables for electrons protons and helium ions (version 1.2.3)2005."},{"key":"e_1_2_8_30_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.apradiso.2020.109246"},{"key":"e_1_2_8_31_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-024-62060-9"},{"key":"e_1_2_8_32_1","unstructured":"International Commission on Radiation Units and Measurements.Determination of Absorbed Dose in a Patient Irradiated by Beams of X or Gamma Rays in Radiotherapy Procedures.International Commission on Radiation Units and Measurements;1976. ICRU Report 24.1976."},{"key":"e_1_2_8_33_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.nima.2025.171189"},{"key":"e_1_2_8_34_1","unstructured":"KamimuraK KurataS HaradaK et\u00a0al.Measurement of neutron depth distribution at boron neutron capture therapy. In:Proceedings of the 38th Workshop on Radiation Detectors and Their Uses. Vol2024 Tsukuba Ibaraki Japan 2025."}],"container-title":["Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mp.70629","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/mp.70629","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mp.70629","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,1]],"date-time":"2026-09-01T13:42:53Z","timestamp":1788270173000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/mp.70629"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8]]},"references-count":33,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8]]}},"alternative-id":["10.1002\/mp.70629"],"URL":"https:\/\/doi.org\/10.1002\/mp.70629","archive":["Portico"],"relation":{},"ISSN":["0094-2405","2473-4209"],"issn-type":[{"value":"0094-2405","type":"print"},{"value":"2473-4209","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8]]},"assertion":[{"value":"2025-10-07","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-14","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-08-10","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70629"}}