{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,21]],"date-time":"2026-01-21T14:04:52Z","timestamp":1769004292350,"version":"3.49.0"},"reference-count":24,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[2024,10,3]],"date-time":"2024-10-03T00:00:00Z","timestamp":1727913600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J Applied Clin Med Phys"],"published-print":{"date-parts":[[2025,1]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>The aim of this study is to determine the impact of rectal air volume changes on treatment plan quality, and subsequently inform daily cone\u2010beam computed tomography (CBCT) evaluation constraints, in terms of acceptable rectal air volume during treatment.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Twelve rectal cancer patients who exhibited rectal air within the PTV on their planning CT were selected. A study was conducted to evaluate the deterioration in plan quality due to expanding air volume. For each case, the air cavity volume was isotropically expanded in three dimensions using predefined margins of 3, 5, 7, and 10\u00a0mm, while deforming bladder and rectum contours. A constraint was applied to the bony anatomy to restrict the deformation. Treatment plans were then generated for all twelve patients by recalculating the reference plan with the expanded air cavity volume.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>As the air cavity expanded, the maximum relative change in D98% coverage, compared to the reference plan, decreased by 10.8%\u00a0\u00b1\u00a03.5%, while the D2% increased by 3.5%\u00a0\u00b1\u00a00.9%. The positioning of the air cavity notably influenced the D98% variability with the 3\u00a0mm expansion. D98% coverage falls below 95% when the air cavity volume exceeds 17 cm<jats:sup>3<\/jats:sup>. On average, D2% coverage increased by 0.5% with each expansion. At the largest expansion, extensive coverage of 102% and 105% isodoses was observed compared to the reference plan.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Air cavity volumes above 17 cm<jats:sup>3<\/jats:sup> can potentially degrade the high\u2010dose PTV coverage while increasing the regions covered by the 102% and 105% isodoses. Clinical CBCT guidelines were deduced, recommending a maximum threshold of 3.2\u00a0cm in diameter in any direction.<\/jats:p><\/jats:sec>","DOI":"10.1002\/acm2.14539","type":"journal-article","created":{"date-parts":[[2024,10,3]],"date-time":"2024-10-03T16:38:36Z","timestamp":1727973516000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Dosimetric impact of variable air cavity within PTV for rectum cancer"],"prefix":"10.1002","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3752-0881","authenticated-orcid":false,"given":"Eujin","family":"Chan","sequence":"first","affiliation":[{"name":"GenesisCare Victoria  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3318-9703","authenticated-orcid":false,"given":"Simon K.","family":"Goodall","sequence":"additional","affiliation":[{"name":"GenesisCare Western Australia  Wembley Western Australia Australia"},{"name":"School of Physics, Mathematics, and Computing, Faculty of Engineering and Mathematical Sciences University of Western Australia  Crawley Western Australia Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Robert","family":"Finnegan","sequence":"additional","affiliation":[{"name":"Royal North Shore Hospital Northern Sydney Cancer Centre  St Leonards New South Wales Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paul","family":"Moorfoot","sequence":"additional","affiliation":[{"name":"GenesisCare Victoria  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael","family":"Jameson","sequence":"additional","affiliation":[{"name":"GenesisCare New South Wales  Alexandria New South Wales Australia"},{"name":"University of New South Wales  Sydney New South Wales Australia"},{"name":"University of Wollongong  Wollongong New South Wales Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leon","family":"Dunn","sequence":"additional","affiliation":[{"name":"GenesisCare Victoria  Melbourne Victoria Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2024,10,3]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa040694"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2011.40.1836"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.3857\/roj.2016.01704"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.3857\/roj.2018.00514"},{"key":"e_1_2_9_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.prnil.2019.12.003"},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13014-016-0681-z"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1259\/bjr.20170512"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v17i6.6207"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2009.08.007"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0360-3016(02)02753-0"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2009.04.022"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.prro.2010.11.006"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12903"},{"key":"e_1_2_9_15_1","first-page":"401","article-title":"The effects of volumetric changes on radiation doses of the rectum and bladder during radiotherapy in patients with prostate cancer","volume":"17","author":"Duman E","year":"2019","journal-title":"Int. J. Radiat Res"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.1007\/s13246-021-01044-9"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1177\/15330338211016370"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.meddos.2014.12.003"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.1016\/0360-3016(95)00225-1"},{"key":"e_1_2_9_20_1","doi-asserted-by":"publisher","DOI":"10.21105\/joss.05374"},{"key":"e_1_2_9_21_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.16388"},{"key":"e_1_2_9_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.phro.2022.02.011"},{"key":"e_1_2_9_23_1","doi-asserted-by":"publisher","DOI":"10.1007\/s13246-023-01231-w"},{"key":"e_1_2_9_24_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/56\/5\/002"},{"key":"e_1_2_9_25_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/53\/3\/011"}],"container-title":["Journal of Applied Clinical Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.14539","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,9]],"date-time":"2025-01-09T10:05:53Z","timestamp":1736417153000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/acm2.14539"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,3]]},"references-count":24,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2025,1]]}},"alternative-id":["10.1002\/acm2.14539"],"URL":"https:\/\/doi.org\/10.1002\/acm2.14539","archive":["Portico"],"relation":{},"ISSN":["1526-9914","1526-9914"],"issn-type":[{"value":"1526-9914","type":"print"},{"value":"1526-9914","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10,3]]},"assertion":[{"value":"2024-05-17","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-09-23","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-10-03","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e14539"}}