{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,9]],"date-time":"2026-10-09T18:29:57Z","timestamp":1791570597276,"version":"4.3.4"},"reference-count":19,"publisher":"Wiley","issue":"3","license":[{"start":{"date-parts":[[2026,3,3]],"date-time":"2026-03-03T00:00:00Z","timestamp":1772496000000},"content-version":"vor","delay-in-days":2,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,3,1]],"date-time":"2026-03-01T00:00:00Z","timestamp":1772323200000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100018893","name":"Scania","doi-asserted-by":"publisher","award":["2022\u20101459"],"award-info":[{"award-number":["2022\u20101459"]}],"id":[{"id":"10.13039\/501100018893","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["aapm.onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["J Applied Clin Med Phys"],"published-print":{"date-parts":[[2026,3]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Precise radiotherapy relies on accurately targeting tumours while minimising exposure to healthy tissue, yet patient and organ motion complicate treatment delivery. To address intra\u2010fractional motion, multi\u2010leaf collimator (MLC) tracking systems have recently been adopted, adapting beam shapes in real\u2010time. The American Association of Physicists in Medicine (AAPM) Task Group 264 (TG\u2010264) provides guidelines for safely commissioning such tracking systems, yet these guidelines were initially developed for conventional linear accelerators and require evaluation, especially for newer platforms such as Radixact Synchrony.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>This study aimed to: (i) evaluate the clinical performance and dosimetric accuracy of the Radixact Synchrony MLC tracking system according to AAPM TG\u2010264 guidelines, from commissioning to clinical implementation; and (ii) critically assess and suggest practical refinements to these guidelines based on experiences with this novel tracking technology.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Commissioning followed TG\u2010264 recommendations, adapted for Radixact Synchrony, utilizing three tracking modes: fiducial\u2010based, markerless adaptive, and marker\u2010based adaptive tracking. Performance was assessed with multiple test systems, including the Delta4 Phantom+, HexaMotion, Quasar platform, and film dosimetry. Measurements included geometric accuracy of phantom trace tracking, dosimetric accuracy of delivered dose to movable phantom, and system latency. Clinical protocols established treatment planning, quality assurance (QA), safety procedures, and clinical decision pathways, focusing on prostate and lung cancer treatments.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The Synchrony system demonstrated substantial improvements in geometric accuracy compared to non\u2010MLC\u2010tracking approaches. Fiducial\u2010based tracking achieved a root mean square error (RMSE) of 0.76\u00a0\u00b1\u00a00.27\u00a0mm compared to 3.99\u00a0\u00b1\u00a02.84\u00a0mm without tracking (\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a00.008), with a mean absolute error (MAE) reduction to 0.36\u00a0\u00b1\u00a00.12\u00a0mm. Markerless adaptive tracking resulted in similar accuracy (RMSE 0.80\u00a0\u00b1\u00a00.15\u00a0mm, MAE 0.68\u00a0\u00b1\u00a00.15\u00a0mm). Dosimetric evaluations revealed consistent improvements, with gamma pass rate \u2265 95% (criteria 2%\/2\u00a0mm) for tracked plans, significantly outperforming static plans under dynamic conditions (\n                      <jats:italic>V<\/jats:italic>\n                      \u00a0=\u00a07.0,\n                      <jats:italic>p<\/jats:italic>\n                      \u00a0=\u00a0.037). System latency was measured one time at approximately 630\u00a0ms for fiducial tracking without external breathing monitoring, slightly exceeding TG\u2010264\u2032s ideal threshold (500\u00a0ms), yet well within the manufacturer's tolerance (1.5 s). Clinical cases confirmed feasibility, showing median deviations of 2.0\u20133.9\u00a0mm for prostate tracking and around 3.3\u00a0mm for markerless lung tracking. Safety protocols and clinical pathways developed during implementation ensured treatment robustness.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>The Radixact Synchrony MLC tracking system successfully met TG\u2010264 guidelines, significantly improving geometric and dosimetric accuracy during real\u2010time tumour tracking. However, practical implementation highlighted necessary adaptations to TG\u2010264 recommendations for non\u2010standard platforms such as Radixact, specifically regarding QA protocols, latency tolerance, and handling of the system's unique characteristics (pneumatic MLC, jaw tracking, and flattening\u2010filter\u2010free beams). Our findings underscore the importance of maintaining conservative margins initially, rigorous QA, specialized staff training, and careful patient selection strategies. Further clinical trials focusing on safe margin reduction strategies are essential for optimizing the clinical benefits of advanced tracking technologies.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/acm2.70492","type":"journal-article","created":{"date-parts":[[2026,3,8]],"date-time":"2026-03-08T23:13:26Z","timestamp":1773011606000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Commissioning and clinical implementation of an MLC tracking system: An evaluation of AAPM TG\u2010264 guidelines"],"prefix":"10.1002","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1694-3738","authenticated-orcid":false,"given":"Andr\u00e9","family":"Haraldsson","sequence":"first","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"},{"name":"Medical Radiation Physics, Department of Clinical Sciences Lund University  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tobias","family":"Pommer","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1509-6431","authenticated-orcid":false,"given":"Emilia","family":"Persson","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"},{"name":"Medical Radiation Physics, Department of Translational Medicine Lund University  Malm\u00f6 Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hedda","family":"Enocsson","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"},{"name":"Medical Radiation Physics, Department of Clinical Sciences Lund University  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mustafa","family":"Kadhim","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"},{"name":"Medical Radiation Physics, Department of Clinical Sciences Lund University  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adalsteinn","family":"Gunnlaugsson","sequence":"additional","affiliation":[{"name":"Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Per","family":"Munck af Rosensch\u00f6ld","sequence":"additional","affiliation":[{"name":"Radiation Physics, Department of Hematology, Oncology &amp; Radiation Physics Sk\u00e5ne University Hospital  Lund Sweden"},{"name":"Medical Radiation Physics, Department of Clinical Sciences Lund University  Lund Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,3,3]]},"reference":[{"key":"e_1_2_9_2_1","doi-asserted-by":"publisher","DOI":"10.1186\/s13014\u2010018\u20100978\u20101"},{"key":"e_1_2_9_3_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2004.11.032"},{"key":"e_1_2_9_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2006.11.014"},{"key":"e_1_2_9_5_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031\u20109155\/61\/4\/1546"},{"key":"e_1_2_9_6_1","unstructured":"AccurayI.Synchrony on the Radixact Real\u2010Time Delivery Adaptation Treatment Delivery System.2021."},{"key":"e_1_2_9_7_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.14171"},{"key":"e_1_2_9_8_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.prro.2021.01.010"},{"key":"e_1_2_9_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12978"},{"key":"e_1_2_9_10_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.15410"},{"key":"e_1_2_9_11_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.13600"},{"key":"e_1_2_9_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12292"},{"key":"e_1_2_9_13_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00066\u2010018\u20101286\u20102"},{"key":"e_1_2_9_14_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2006.10.026"},{"key":"e_1_2_9_15_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2007.11.054"},{"key":"e_1_2_9_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.13034"},{"key":"e_1_2_9_17_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12847"},{"key":"e_1_2_9_18_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.14625"},{"key":"e_1_2_9_19_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41597\u2010019\u20100280\u20106"},{"key":"e_1_2_9_20_1","unstructured":"Real\u2010time motion management during prostate and lung radiotherapy.2023.https:\/\/clinicaltrials.gov\/study\/NCT05844761"}],"container-title":["Journal of Applied Clinical Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.70492","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/full-xml\/10.1002\/acm2.70492","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.70492","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,22]],"date-time":"2026-03-22T03:48:23Z","timestamp":1774151303000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/acm2.70492"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3]]},"references-count":19,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,3]]}},"alternative-id":["10.1002\/acm2.70492"],"URL":"https:\/\/doi.org\/10.1002\/acm2.70492","archive":["Portico"],"relation":{},"ISSN":["1526-9914","1526-9914"],"issn-type":[{"value":"1526-9914","type":"print"},{"value":"1526-9914","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3]]},"assertion":[{"value":"2025-08-19","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-12-29","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-03-03","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e70492"}}