{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T15:24:25Z","timestamp":1789658665828,"version":"4.0.1"},"reference-count":24,"publisher":"Wiley","issue":"10","license":[{"start":{"date-parts":[[2018,9,19]],"date-time":"2018-09-19T00:00:00Z","timestamp":1537315200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Uppsala-\u00d6rebro Regional Research Council"},{"name":"The Research Committee in Region \u00d6rebro Council"}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Medical Physics"],"published-print":{"date-parts":[[2018,10]]},"abstract":"Purpose<\/jats:title>To evaluate two commercial CT<\/jats:styled-content> metal artifact reduction (MAR<\/jats:styled-content>) algorithms for use in proton treatment planning in the head and neck (H&N) area.<\/jats:p><\/jats:sec>Methods<\/jats:title>An anthropomorphic head phantom with removable metallic implants (dental fillings or neck implant) was CT<\/jats:styled-content>\u2010scanned to evaluate the O\u2010MAR (Philips) and the iMAR<\/jats:styled-content> (Siemens) algorithms. Reference images were acquired without any metallic implants in place. Water equivalent thickness (WET<\/jats:styled-content>) was calculated for different path directions and compared between image sets. Images were also evaluated for use in proton treatment planning for parotid, tonsil, tongue base, and neck node targets. The beams were arranged so as to not traverse any metal prior to the target, enabling evaluation of the impact on dose calculation accuracy from artifacts surrounding the metal volume. Plans were compared based on \u03b3<\/jats:italic> analysis (1 mm distance\u2010to\u2010agreement\/1% difference in local dose) and dose volume histogram metrics for targets and organs at risk (OAR<\/jats:styled-content>s). Visual grading evaluation of 30 dental implant patient MAR<\/jats:styled-content> images was performed by three radiation oncologists.<\/jats:p><\/jats:sec>Results<\/jats:title>In the dental fillings images, \u0394WET<\/jats:styled-content> along a low\u2010density streak was reduced from \u221217.0 to \u22124.3 mm with O\u2010MAR<\/jats:styled-content> and from \u221216.1 mm to \u22122.3 mm with iMAR<\/jats:styled-content>, while for other directions the deviations were increased or approximately unchanged when the MAR algorithms were used. For the neck implant images, \u0394WET<\/jats:styled-content> was generally reduced with MAR<\/jats:styled-content> but residual deviations remained (of up to \u22122.3 mm with O\u2010MAR and of up to \u22121.5 mm with iMAR<\/jats:styled-content>). The \u03b3<\/jats:italic> analysis comparing proton dose distributions for uncorrected\/MAR<\/jats:styled-content> plans and corresponding reference plans showed passing rates >98% of the voxels for all phantom plans. However, substantial dose differences were seen in areas of most severe artifacts (\u03b3<\/jats:italic> passing rates of down to 89% for some cases). MAR<\/jats:styled-content> reduced the deviations in some cases, but not for all plans. For a single patient case dosimetrically evaluated, minor dose differences were seen between the uncorrected and MAR<\/jats:styled-content> plans (\u03b3<\/jats:italic> passing rate approximately 97%). The visual grading of patient images showed that MAR<\/jats:styled-content> significantly improved image quality (P<\/jats:italic> < 0.001).<\/jats:p><\/jats:sec>Conclusions<\/jats:title>O\u2010MAR<\/jats:styled-content> and iMAR<\/jats:styled-content> significantly improved image quality in terms of anatomical visualization for target and OAR<\/jats:styled-content> delineation in dental implant patient images. WET<\/jats:styled-content> calculations along several directions, all outside the metallic regions, showed that both uncorrected and MAR<\/jats:styled-content> images contained metal artifacts which could potentially lead to unacceptable errors in proton treatment planning. \u0394WET<\/jats:styled-content> was reduced by MAR<\/jats:styled-content> in some areas, while increased or unchanged deviations were seen for other path directions. The proton treatment plans created for the phantom images showed overall acceptable dose distributions differences when compared to the reference cases, both for the uncorrected and MAR<\/jats:styled-content> images. However, substantial dose distribution differences in the areas of most severe artifacts were seen for some plans, which were reduced by MAR<\/jats:styled-content> in some cases but not all. In conclusion, MAR<\/jats:styled-content> could be beneficial to use for proton treatment planning; however, case\u2010by\u2010case evaluations of the metal artifact\u2010degraded images are always recommended.<\/jats:p><\/jats:sec>","DOI":"10.1002\/mp.13115","type":"journal-article","created":{"date-parts":[[2018,8,7]],"date-time":"2018-08-07T06:51:41Z","timestamp":1533624701000},"page":"4329-4344","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":49,"title":["Evaluation of two commercial CT<\/scp> metal artifact reduction algorithms for use in proton radiotherapy treatment planning in the head and neck area"],"prefix":"10.1002","volume":"45","author":[{"given":"Karin M.","family":"Andersson","sequence":"first","affiliation":[{"name":"The Skandion Clinic 752 37 Uppsala Sweden"},{"name":"School of Health and Medical Sciences \u00d6rebro University 70182 \u00d6rebro Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christina Vallhagen","family":"Dahlgren","sequence":"additional","affiliation":[{"name":"The Skandion Clinic 752 37 Uppsala Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Johan","family":"Reizenstein","sequence":"additional","affiliation":[{"name":"Department of Oncology Faculty of Medicine and Health \u00d6rebro University 70182 \u00d6rebro Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Cao","sequence":"additional","affiliation":[{"name":"Clinical Epidemiology and Biostatistics School of Medical Sciences \u00d6rebro University 70182 \u00d6rebro Sweden"},{"name":"Unit of Biostatistics Institute of Environmental Medicine Karolinska Institutet 17177 Stockholm Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anders","family":"Ahnesj\u00f6","sequence":"additional","affiliation":[{"name":"Medical Radiation Sciences Department of Immunology, Genetics and Pathology Uppsala University 751 85 Uppsala Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Per","family":"Thunberg","sequence":"additional","affiliation":[{"name":"Department of Medical Physics Faculty of Medicine and Health \u00d6rebro University 70182 \u00d6rebro Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2018,9,19]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/41\/1\/009"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmp.2011.02.001"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/45\/2\/314"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aa5293"},{"key":"e_1_2_8_6_1","first-page":"20140473","article-title":"Metal artefact reduction in CT imaging of hip prostheses\u2010an evaluation of commercial techniques provided by four vendors","volume":"2015","author":"Andersson KM","journal-title":"Br J Radiol"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00330-011-2062-1"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4762814"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v15i5.4857"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4906245"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00066-016-0958-z"},{"key":"e_1_2_8_12_1","first-page":"20140536","article-title":"Evaluation of a commercial orthopaedic metal artefact reduction tool in radiation therapy of patients with head and neck cancer","volume":"2015","author":"Kwon H","journal-title":"Br J Radiol"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1080\/0284186X.2017.1287427"},{"key":"e_1_2_8_14_1","unstructured":"Philips Healthcare.Metal Artifact Reduction for Orthopedic Implants (O\u2010MAR). White paper USA;2012[Available from:http:\/\/clinical.netforum.healthcare.philips.com\/us_en\/Explore\/White-Papers\/CT\/Metal-Artifact-Reduction-for-Orthopedic-Implants-(O-MAR)."},{"key":"e_1_2_8_15_1","volume-title":"Iterative Metal Artifact Reduction (iMAR): Technical Principles and Clinical Results in Radiation Therapy (White paper)","author":"Kachelrei\u00df M","year":"2015"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3484090"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3691902"},{"key":"e_1_2_8_18_1","doi-asserted-by":"publisher","DOI":"10.1259\/0007-1285-60-717-907"},{"key":"e_1_2_8_19_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/57\/13\/4095"},{"key":"e_1_2_8_20_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/54\/6\/001"},{"key":"e_1_2_8_21_1","doi-asserted-by":"publisher","DOI":"10.1259\/bjr\/35254923"},{"key":"e_1_2_8_22_1","first-page":"20150993","article-title":"Visual grading evaluation of commercially available metal artefact reduction techniques in hip prosthesis computed tomography","volume":"2016","author":"Andersson KM","journal-title":"Br J Radiol"},{"key":"e_1_2_8_23_1","doi-asserted-by":"publisher","DOI":"10.1198\/000313006X152207"},{"key":"e_1_2_8_24_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/52\/10\/009"},{"key":"e_1_2_8_25_1","doi-asserted-by":"publisher","DOI":"10.2214\/AJR.13.10980"}],"container-title":["Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fmp.13115","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mp.13115","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,28]],"date-time":"2023-09-28T18:30:15Z","timestamp":1695925815000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/mp.13115"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,9,19]]},"references-count":24,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2018,10]]}},"alternative-id":["10.1002\/mp.13115"],"URL":"https:\/\/doi.org\/10.1002\/mp.13115","archive":["Portico"],"relation":{},"ISSN":["0094-2405","2473-4209"],"issn-type":[{"value":"0094-2405","type":"print"},{"value":"2473-4209","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,9,19]]},"assertion":[{"value":"2017-09-06","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-07-26","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2018-09-19","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}