{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T23:26:11Z","timestamp":1792106771549,"version":"4.4.0"},"reference-count":30,"publisher":"Oxford University Press (OUP)","issue":"8","license":[{"start":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T00:00:00Z","timestamp":1745366400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,8,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Precise patient positioning is crucial for successful radiotherapy, ensuring accurate delivery of radiation to tumors while minimizing exposure to healthy tissues. Positional errors can significantly impact treatment efficacy and increase side effects. This study evaluates the effectiveness of daily cone beam computed tomography (CBCT) imaging in the Halcyon system for detecting and correcting patient misalignments across various cancer types and treatment sites.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A retrospective analysis was conducted on 411 patients treated with the Varian Halcyon linear accelerator from August 2022 to August 2024. Patients were grouped based on tumor location: Head and Neck (118 patients), Chest (188 patients), and Pelvis (105 patients). Daily pre-treatment CBCT scans were performed to verify positioning, with shifts in the x, y, and z axes quantified and adjusted using automated couch corrections.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>The study revealed average positional shifts along the x-axis of ~0.112\u00a0cm, while both the Chest and Pelvic groups recorded 0.194\u00a0cm. The y-axis deviations were 0.135\u00a0cm for Head and Neck, 0.206\u00a0cm for Chest, and 0.195\u00a0cm for the Pelvis. On the z-axis, a mean deviation of 0.07\u00a0cm was found for the Head and Neck group, while 0.11\u00a0cm for the Chest group, and 0.085\u00a0cm for the Pelvic group. The Head and Neck group exhibited the smallest standard deviations across all axes, indicating greater positional consistency. Normalized density distributions showed distinct emergent patterns, the Head and Neck group showing tighter distributions compared to the broader distributions observed in the Chest and Pelvic groups.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Daily CBCT imaging in the Halcyon system significantly enhances patient positioning accuracy in radiotherapy. The findings demonstrate that this approach minimizes positional shifts, particularly in the Head and Neck region, essential for optimizing treatment outcomes and reducing the risk of adverse effects. Future studies should further explore the integration of advanced imaging techniques to improve precision in patient positioning.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jjco\/hyaf067","type":"journal-article","created":{"date-parts":[[2025,4,9]],"date-time":"2025-04-09T07:24:07Z","timestamp":1744183447000},"page":"925-932","source":"Crossref","is-referenced-by-count":10,"title":["Enhancing patient positioning accuracy: evaluating daily cone beam computed tomography in the halcyon system"],"prefix":"10.1093","volume":"55","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7276-8105","authenticated-orcid":false,"given":"Duong Thanh","family":"Tai","sequence":"first","affiliation":[{"name":"Department of Medical Physics, Faculty of Medicine, Nguyen Tat Thanh University , 298-300A Nguyen Tat Thanh Street, Ward 13, District 4, Ho Chi Minh City 700000 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Hanoi 12116 ,","place":["Vietnam"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2768-6503","authenticated-orcid":false,"given":"Nguyen Xuan","family":"Hai","sequence":"additional","affiliation":[{"name":"Center for Analytical Techniques, Dalat Nuclear Research Institute , 01 Nguyen Tu Luc Street, Ward 8, Da Lat City, Lam Dong Province 670000 ,","place":["Vietnam"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9962-7281","authenticated-orcid":false,"given":"Peter","family":"Sandwall","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, OhioHealth Mansfield Hospital , 330 Glessner Avenue, Mansfield, OH 44903 ,","place":["United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9485-5242","authenticated-orcid":false,"given":"David","family":"Bradley","sequence":"additional","affiliation":[{"name":"Applied Radiation Physics and Technologies Group, Department of Engineering, Sunway University , No. 5 Jalan Universiti, Bandar Sunway, Subang Jaya, 46150 Petaling Jaya, Selangor ,","place":["Malaysia"]},{"name":"School of Mathematics and Physics, University of Surrey , Stag Hill Campus, University Road, Guildford, Surrey GU2 7XH ,","place":["United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4202-4855","authenticated-orcid":false,"given":"James C L","family":"Chow","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University of Toronto , 610 University Avenue, Toronto, Ontario M5G 2M9 ,","place":["Canada"]},{"name":"Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network , 610 University Avenue, Toronto, Ontario M5G 1X6 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