{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T18:53:24Z","timestamp":1778698404985,"version":"3.51.4"},"reference-count":21,"publisher":"Wiley","issue":"5","license":[{"start":{"date-parts":[[2016,11,30]],"date-time":"2016-11-30T00:00:00Z","timestamp":1480464000000},"content-version":"vor","delay-in-days":579,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2015,9,1]],"date-time":"2015-09-01T00:00:00Z","timestamp":1441065600000},"content-version":"tdm","delay-in-days":123,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"name":"Varian Medical Systems, Palo Alto, CA"},{"name":"Vision RT Ltd., United Kingdom"},{"DOI":"10.13039\/100000002","name":"National Institutes of Health (NIH)","doi-asserted-by":"publisher","award":["R01CA169102"],"award-info":[{"award-number":["R01CA169102"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R01CA169102"],"award-info":[{"award-number":["R01CA169102"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Varian Medical Systems, Palo Alto, CA"},{"name":"Vision RT Ltd., United Kingdom"},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["R01CA169102"],"award-info":[{"award-number":["R01CA169102"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["aip.org"],"crossmark-restriction":true},"short-container-title":["Medical Physics"],"published-print":{"date-parts":[[2015,5]]},"abstract":"<jats:sec><jats:title>Purpose:<\/jats:title><jats:p>Most clinically deployed strategies for respiratory motion management in lung radiotherapy (e.g., gating and tracking) use external markers that serve as surrogates for tumor motion. However, typical lung phantoms used to validate these strategies are based on a rigid exterior and a rigid or a deformable\u2010interior. Such designs do not adequately represent respiration because the thoracic anatomy deforms internally as well as externally. In order to create a closer approximation of respiratory motion, the authors describe the construction and experimental testing of an externally as well as internally deformable, programmable lung phantom.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods:<\/jats:title><jats:p>The outer shell of a commercially available lung phantom (RS\u20101500, RSD, Inc.) was used. The shell consists of a chest cavity with a flexible anterior surface, and embedded vertebrae, rib\u2010cage and sternum. A custom\u2010made insert was designed using a piece of natural latex foam block. A motion platform was programmed with sinusoidal and ten patient\u2010recorded lung tumor trajectories. The platform was used to drive a rigid foam \u201cdiaphragm\u201d that compressed\/decompressed the phantom interior. Experimental characterization comprised of determining the reproducibility and the external\u2013internal correlation of external and internal marker trajectories extracted from kV x\u2010ray fluoroscopy. Experiments were conducted to illustrate three example applications of the phantom\u2014(i) validating the geometric accuracy of the VisionRT surface photogrammetry system; (ii) validating an image registration tool, NiftyReg; and (iii) quantifying the geometric error due to irregular motion in four\u2010dimensional computed tomography (4DCT).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results:<\/jats:title><jats:p>The phantom correctly reproduced sinusoidal and patient\u2010derived motion, as well as realistic respiratory motion\u2010related effects such as hysteresis. The reproducibility of marker trajectories over multiple runs for sinusoidal as well as patient traces, as characterized by fluoroscopy, was within 0.25 mm RMS error. The motion trajectories of internal and external radio\u2010opaque markers as measured by fluoroscopy were found to be highly correlated (R &gt; 0.95). Using the phantom, it was demonstrated that the motion trajectories of regions\u2010of\u2010interest on the surface as measured by VisionRT are highly consistent with corresponding fluoroscopically acquired surface marker trajectories, with RMS errors within 0.26 mm. Furthermore, it was shown that the trajectories of external and internal marker trajectories derived from NiftyReg deformation vector fields were within 1 mm root mean square errors comparing to trajectories obtained by segmenting markers from individual fluoro frames. Finally, it was shown that while 4DCT can be used to localize internal markers for sinusoidal motion with reasonable accuracy, the localization error increases significantly (by a factor of \u223c2) in the presence of cycle\u2010to\u2010cycle variations that are observed in patient\u2010derived respiratory motion.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions:<\/jats:title><jats:p>The authors have developed a realistic externally and internally deformable, programmable lung phantom that will serve as a valuable tool for clinical and investigational motion management studies in thoracic and abdominal radiation therapies.<\/jats:p><\/jats:sec>","DOI":"10.1118\/1.4918581","type":"journal-article","created":{"date-parts":[[2015,4,25]],"date-time":"2015-04-25T00:30:08Z","timestamp":1429921808000},"page":"2585-2593","update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":28,"title":["An externally and internally deformable, programmable lung motion phantom"],"prefix":"10.1002","volume":"42","author":[{"given":"Yam","family":"Cheung","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amit","family":"Sawant","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2016,11,30]]},"reference":[{"key":"e_1_2_6_2_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v9i2.2758"},{"key":"e_1_2_6_3_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2836417"},{"key":"e_1_2_6_4_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v11i1.3081"},{"key":"e_1_2_6_5_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/51\/14\/005"},{"key":"e_1_2_6_6_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2400612"},{"key":"e_1_2_6_7_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3496356"},{"key":"e_1_2_6_8_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3676185"},{"key":"e_1_2_6_9_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/52\/18\/n02"},{"key":"e_1_2_6_10_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/57\/8\/2235"},{"key":"e_1_2_6_11_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2761600"},{"key":"e_1_2_6_12_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/53\/13\/016"},{"key":"e_1_2_6_13_1","first-page":"33","article-title":"Lung registration using the NiftyReg package","author":"Modat M.","year":"2010","journal-title":"Med. Image Anal. Clin.\u2010A Grand Challenge"},{"key":"e_1_2_6_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2004.06.021"},{"key":"e_1_2_6_15_1","doi-asserted-by":"publisher","DOI":"10.1053\/j.semradonc.2003.10.006"},{"key":"e_1_2_6_16_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.2027.25373"},{"key":"e_1_2_6_17_1","doi-asserted-by":"publisher","DOI":"10.1016\/s0360\u20103016(02)02803\u20101"},{"key":"e_1_2_6_18_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2241993"},{"key":"e_1_2_6_19_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.2828197"},{"key":"e_1_2_6_20_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v14i6.4363"},{"key":"e_1_2_6_21_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4811102"},{"key":"e_1_2_6_22_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4794178"}],"container-title":["Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1118%2F1.4918581","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1118%2F1.4918581","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1118\/1.4918581","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,18]],"date-time":"2023-09-18T08:17:16Z","timestamp":1695025036000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1118\/1.4918581"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,5]]},"references-count":21,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2015,5]]}},"alternative-id":["10.1118\/1.4918581"],"URL":"https:\/\/doi.org\/10.1118\/1.4918581","archive":["Portico"],"relation":{},"ISSN":["0094-2405","2473-4209"],"issn-type":[{"value":"0094-2405","type":"print"},{"value":"2473-4209","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,5]]},"assertion":[{"value":"2014-06-12","order":0,"name":"received","label":"received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-04-01","order":1,"name":"revised","label":"revised","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-04-07","order":2,"name":"accepted","label":"accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2015-04-24","order":6,"name":"published","label":"published","group":{"name":"publication_history","label":"Publication History"}}]}}