{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T18:53:37Z","timestamp":1784055217552,"version":"3.55.0"},"reference-count":16,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2022,3,14]],"date-time":"2022-03-14T00:00:00Z","timestamp":1647216000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Medical Physics"],"published-print":{"date-parts":[[2022,5]]},"abstract":"<jats:sec><jats:title>Purpose<\/jats:title><jats:p>To develop a system for detecting anatomical changes using two\u2010dimensional (2D) x\u2010ray images.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Ten patients with head and neck cancer were retrospectively analyzed using 2D x\u2010ray and cone\u2010beam computed tomography (CBCT) images. The 2D x\u2010ray images were acquired daily, whereas the CBCT images were acquired weekly during the treatment period. The developed system imported the 2D x\u2010ray images obtained on the initial treatment day and on another day, and thereafter converted them into the water equivalent thickness (WET) using the conversion table. The difference between the WET images for the first and other treatment days (\u0394WET) was calculated as the quantitative value for anatomical changes and visualized to recognize the anatomical change location. We compared \u0394WET and the difference in the lateral neck distance (\u0394LND) on the corresponding CBCT images. \u0394LND was used as the ground truth for anatomical changes. \u0394WET and \u0394LND were measured at the first cervical vertebra (C1) and the tumor center (TC). C1 and TC were selected to observe the volume changes in the parotid gland and tumor, respectively. Sensitivity and specificity were calculated to evaluate the performance of the 2D\u2010WET system. The cut\u2010off values of WET and LND were set to 2\u201310\u00a0mm. Furthermore, intensity\u2010modulated proton therapy (IMPT) plans for six patients with rescan CT images were generated. The IMPT plans on the rescan CT images were compared to the original plans on simulation CT using the dosimetric parameters for the target and the organs at risk.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The mean differences between \u0394WET and \u0394LND for C1 and TC were \u22120.62 \u00b1 1.66\u00a0mm and \u22120.93 \u00b1 1.28\u00a0mm (mean \u00b1 1 SD), respectively. \u0394WET in the proposed system was in good agreement with \u0394LND using the CBCT images. In the sensitivity and specificity results for C1 and TC with cut\u2010off values from 2 to 10\u00a0mm, the sensitivity was\u00a0&gt;85% for all cut\u2010off values, while the specificity was\u00a0&gt;90% at 5\u201310\u00a0mm and\u00a0&lt;90% at less than 5\u00a0mm. The average \u0394WET at the time of replanning was 12.8\u00a0mm which resulted in maximum dose increase in the spinal cord D1cc by 8.4\u00a0Gy, the parotid gland D50 by 26.6\u00a0Gy, and the oral cavity D50 by 23.2\u00a0Gy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>We developed a new system for detecting anatomical changes using 2D x\u2010ray images. The developed system with \u0394WET showed an agreement with \u0394LND at C1 and TC with an average difference of less than 1\u00a0mm. \u0394WET detected anatomical changes with high sensitivity and specificity with a cut\u2010off value of 5\u201310\u00a0mm. This system can monitor daily anatomical changes without causing high exposure to patients and requiring any inefficient work, and it can be applied to daily online adaptive proton beam therapy and triggered adaptive radiotherapy.<\/jats:p><\/jats:sec>","DOI":"10.1002\/mp.15587","type":"journal-article","created":{"date-parts":[[2022,3,2]],"date-time":"2022-03-02T16:10:25Z","timestamp":1646237425000},"page":"3288-3297","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Detection of anatomical changes using two\u2010dimensional x\u2010ray images for head and neck adaptive radiotherapy"],"prefix":"10.1002","volume":"49","author":[{"given":"Kouta","family":"Hirotaki","sequence":"first","affiliation":[{"name":"Doctoral Program in Medical Sciences, Graduate School of Comprehensive Human Sciences University of Tsukuba  Ibaraki Japan"},{"name":"Department of Radiological Technology National Cancer Center Hospital East  Chiba Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shunsuke","family":"Moriya","sequence":"additional","affiliation":[{"name":"Faculty of Medicine University of Tsukuba  Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hidenobu","family":"Tachibana","sequence":"additional","affiliation":[{"name":"Section of Radiation Safety and Quality Assurance National Cancer Center Hospital East  Chiba Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takeji","family":"Sakae","sequence":"additional","affiliation":[{"name":"Faculty of Medicine University of Tsukuba  Ibaraki Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2022,3,14]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.semradonc.2019.02.007"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.semradonc.2019.02.008"},{"key":"e_1_2_8_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2010.03.014"},{"key":"e_1_2_8_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2014.02.017"},{"key":"e_1_2_8_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2012.10.010"},{"key":"e_1_2_8_7_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13014-019-1350-9"},{"key":"e_1_2_8_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2011.05.028"},{"key":"e_1_2_8_9_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4813900"},{"key":"e_1_2_8_10_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v17i2.5819"},{"key":"e_1_2_8_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.13045"},{"key":"e_1_2_8_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2016.01.055"},{"key":"e_1_2_8_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmp.2014.10.075"},{"key":"e_1_2_8_14_1","doi-asserted-by":"publisher","DOI":"10.1259\/bjr.20170266"},{"key":"e_1_2_8_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2014.07.005"},{"key":"e_1_2_8_16_1","doi-asserted-by":"publisher","DOI":"10.1259\/bjr.20150195"},{"key":"e_1_2_8_17_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3187229"}],"container-title":["Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mp.15587","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/mp.15587","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/mp.15587","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,8,19]],"date-time":"2023-08-19T14:59:24Z","timestamp":1692457164000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/mp.15587"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,14]]},"references-count":16,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2022,5]]}},"alternative-id":["10.1002\/mp.15587"],"URL":"https:\/\/doi.org\/10.1002\/mp.15587","archive":["Portico"],"relation":{},"ISSN":["0094-2405","2473-4209"],"issn-type":[{"value":"0094-2405","type":"print"},{"value":"2473-4209","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,3,14]]},"assertion":[{"value":"2021-09-01","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2022-02-23","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2022-03-14","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}