{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T13:54:09Z","timestamp":1791986049818,"version":"4.4.0"},"reference-count":27,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T00:00:00Z","timestamp":1770854400000},"content-version":"vor","delay-in-days":11,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T00:00:00Z","timestamp":1769904000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J Applied Clin Med Phys"],"published-print":{"date-parts":[[2026,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>This study quantifies isocenter and off\u2010axis geometric uncertainties using MultiMet Winston\u2013Lutz (WL) tests to optimize gross tumour volume (GTV)\u2010to\u2010PTV (planning target volume) margin for single isocenter multiple target (SIMT) stereotactic body radiotherapy (SBRT) across three linear accelerators.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods and Materials<\/jats:title>\n                    <jats:p>Geometric inaccuracies were quantified for Trilogy (HD\u2010MLC, 6 MV SRS), TrueBeam (Millennium MLC), and TrueBeam STx (HD\u2010MLC, 6\u2010degrees\u2010of\u2010freedom (6DoF) couch) using a Sun Nuclear MultiMet\u2010WL cube containing six tungsten carbide markers arranged along the superior\u2013inferior axis. The electronic portal imaging device (EPID) images acquired at four cardinal gantry angles with varied collimator\/couch rotations were analyzed using MultiMet\u2010WL software (v2.1) to measure 3D (\u0394) displacements for all the LINACs. The required GTV\u2010to\u2010PTV margins were calculated using a modified van Herk formula (2.5\u03a3+1.64\u03c3), incorporating measured 3D displacements for isocenter and off\u2010axis targets.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The TrueBeam STx (HD\u2010MLC\/6DoF) demonstrated superior geometric accuracy, maintaining \u22640.5\u00a0mm isocenter precision and \u22640.59\u00a0mm off\u2010axis targeting (3\u20137\u00a0cm). The Trilogy exceeded TG\u2010142 tolerances (1.06\u00a0\u00b1\u00a00.59 to 1.09\u00a0\u00b1\u00a00.57\u00a0mm) at all targets, requiring 4\u00a0mm uniform margins, while the TrueBeam (MMLC) showed optimal variations (isocenter: 0.68\u00a0\u00b1\u00a00.34\u00a0mm; superior off\u2010axis: 0.74\u00a0\u00b1\u00a00.36\u00a0mm). Both TrueBeam platforms achieved sub\u2010millimeter accuracy but demonstrated direction dependency for off\u2010axis targets, requiring 2\u20133\u00a0mm anisotropic margins. Notably, isotropic margins introduced up to 11% delineation errors for off\u2010axis targets due to these machine\u2010specific geometric variations, highlighting the imperative for platform\u2010specific margin protocols in SIMT SBRT.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study demonstrates that routine analysis of MultiMet WL testing is an essential tool for the spatial accuracy of the LINAC to establish machine\u2010specific PTV margin expansion in SIMT\u2010SBRT, particularly for targets where rotational errors dominate.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/acm2.70383","type":"journal-article","created":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T02:04:52Z","timestamp":1770948292000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The geometric accuracy of off\u2010axis targets in stereotactic body radiotherapy treatments across three linear accelerators"],"prefix":"10.1002","volume":"27","author":[{"given":"Dinesan","family":"Chinnaiya","sequence":"first","affiliation":[{"name":"Department of Physics School of Advanced Sciences Vellore Institute of Technology  Chennai India"},{"name":"Department of Radiation Oncology Sri Shankara Cancer Hospital &amp; Research Centre  Bangalore India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gopinath","family":"Mudhana","sequence":"additional","affiliation":[{"name":"Department of Physics School of Advanced Sciences Vellore Institute of Technology  Chennai India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,2,12]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12938"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2021.11.030"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.1177\/15330338241229363"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2018.06.187"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12500"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v15i4.4737"},{"key":"e_1_2_11_8_1","first-page":"265","article-title":"SBRT treatment of multiple extracranial oligometastases using a single isocenter with distinct optimizations","volume":"4","author":"Trager M","year":"2017","journal-title":"J Radiosurg SBRT"},{"key":"e_1_2_11_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmp.2020.10.022"},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2021.07.582"},{"key":"e_1_2_11_11_1","doi-asserted-by":"publisher","DOI":"10.7759\/cureus.68904"},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejmp.2023.102645"},{"key":"e_1_2_11_13_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41598\u2010024\u201057644\u20104"},{"key":"e_1_2_11_14_1","doi-asserted-by":"publisher","DOI":"10.1038\/srep34511"},{"key":"e_1_2_11_15_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3438081"},{"key":"e_1_2_11_16_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3190392"},{"key":"e_1_2_11_17_1","doi-asserted-by":"publisher","DOI":"10.1120\/jacmp.v17i1.5792"},{"key":"e_1_2_11_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.14992"},{"key":"e_1_2_11_19_1","doi-asserted-by":"publisher","DOI":"10.4236\/ijmpcero.2016.52017"},{"key":"e_1_2_11_20_1","doi-asserted-by":"publisher","DOI":"10.1007\/s12194\u2010020\u201000602\u20102"},{"key":"e_1_2_11_21_1","doi-asserted-by":"publisher","DOI":"10.1016\/s0360\u20103016(00)00518\u20106"},{"key":"e_1_2_11_22_1","doi-asserted-by":"publisher","DOI":"10.3389\/fonc.2019.00319"},{"key":"e_1_2_11_23_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12197"},{"key":"e_1_2_11_24_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.597475"},{"key":"e_1_2_11_25_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.1800712"},{"key":"e_1_2_11_26_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361\u20106560\/aab231"},{"key":"e_1_2_11_27_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.14470"},{"key":"e_1_2_11_28_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13014\u2010019\u20101334\u20109"}],"container-title":["Journal of Applied Clinical Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.70383","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/acm2.70383","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.70383","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T13:43:29Z","timestamp":1791985409000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/acm2.70383"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2]]},"references-count":27,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2026,2]]}},"alternative-id":["10.1002\/acm2.70383"],"URL":"https:\/\/doi.org\/10.1002\/acm2.70383","archive":["Portico"],"relation":{},"ISSN":["1526-9914","1526-9914"],"issn-type":[{"value":"1526-9914","type":"print"},{"value":"1526-9914","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2]]},"assertion":[{"value":"2025-08-13","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-11-03","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-02-12","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70383"}}