{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T05:32:46Z","timestamp":1782279166836,"version":"3.54.5"},"reference-count":25,"publisher":"Wiley","issue":"9","license":[{"start":{"date-parts":[[2024,6,23]],"date-time":"2024-06-23T00:00:00Z","timestamp":1719100800000},"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":[[2024,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>A higher minimum monitor unit (minMU) for pencil\u2010beam scanning proton beams in intensity\u2010modulated proton therapy is preferred for more efficient delivery. However, plan quality may be compromised when the minMU is too large.<\/jats:p><jats:p>This study aimed to identify the optimal minMU (OminMU) to improve plan delivery efficiency while maintaining high plan quality.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We utilized clinical plans including six anatomic sites (brain, head and neck, breast, lung, abdomen, and prostate) from 23 patients previously treated with the Varian ProBeam system. The minMU of each plan was increased from the current clinical minMU of 1.1 to 3\u201324 MU depending on the daily prescribed dose (DPD). The dosimetric parameters of the plans were evaluated for consistency against a 1.1\u2010minMU plan for target coverage as well as organs\u2010at\u2010risk dose sparing. DPD\/minMU was defined as the ratio of DPD to minMU (cGy\/MU) to find the OminMU by ensuring that dosimetric parameters did not differ by\u00a0&gt;1% compared to those of the 1.1\u2010minMU plan.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>All plans up to 5 minMU showed no significant dose differences compared to the 1.1\u2010minMU plan. Plan qualities remained acceptable when DPD\/minMU \u226535 cGy\/MU. This suggests that the 35 cGy\/MU criterion can be used as the OminMU, which implies that 5 MU is the OminMU for a conventional fraction dose of 180 cGy. Treatment times were decreased by an average of 32% (max 56%, min 7%) and by an average of 1.6\u00a0min when the minMU was increased from 1.1 to OminMU.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>A clinical guideline for OminMU has been established. The minMU can be increased by 1 MU for every 35 cGy of DPD without compromising plan quality for most cases analyzed in this study. Significant treatment time reduction of up to 56% was observed when the suggested OminMU is used.<\/jats:p><\/jats:sec>","DOI":"10.1002\/acm2.14435","type":"journal-article","created":{"date-parts":[[2024,6,23]],"date-time":"2024-06-23T20:50:00Z","timestamp":1719175800000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Optimal minimum MU for intensity\u2010modulated proton therapy with pencil\u2010beam scanning proton beams"],"prefix":"10.1002","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8805-0250","authenticated-orcid":false,"given":"ByongYong","family":"Yi","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology University of Maryland School of Medicine  Baltimore Maryland USA"},{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9007-3112","authenticated-orcid":false,"given":"Sina","family":"Mossahebi","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology University of Maryland School of Medicine  Baltimore Maryland USA"},{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jenna","family":"Jatczak","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michelle","family":"Mundis","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thomas","family":"Houser","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Alicia","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4010-1220","authenticated-orcid":false,"given":"Dong","family":"Han","sequence":"additional","affiliation":[{"name":"New York Proton Center  New York New York USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-7516-6614","authenticated-orcid":false,"given":"Rosette","family":"Gonzalez","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-4705-4316","authenticated-orcid":false,"given":"Stephen","family":"Olis","sequence":"additional","affiliation":[{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4333-648X","authenticated-orcid":false,"given":"Mark","family":"Zakhary","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology University of Maryland School of Medicine  Baltimore Maryland USA"},{"name":"Maryland Proton Treatment Center  Baltimore Maryland USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2024,6,23]]},"reference":[{"key":"e_1_2_10_2_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/61\/12\/4665"},{"key":"e_1_2_10_3_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.4892057"},{"key":"e_1_2_10_4_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/61\/1\/400"},{"key":"e_1_2_10_5_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3314073"},{"key":"e_1_2_10_6_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ab3317"},{"key":"e_1_2_10_7_1","doi-asserted-by":"publisher","DOI":"10.1088\/0031-9155\/58\/15\/5113"},{"key":"e_1_2_10_8_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.12677"},{"key":"e_1_2_10_9_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ab2133"},{"key":"e_1_2_10_10_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ab4529"},{"key":"e_1_2_10_11_1","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/ac4212"},{"key":"e_1_2_10_12_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.16577"},{"key":"e_1_2_10_13_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.14363"},{"key":"e_1_2_10_14_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.13997"},{"key":"e_1_2_10_15_1","doi-asserted-by":"publisher","DOI":"10.3390\/cancers15164084"},{"key":"e_1_2_10_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2023.01.048"},{"key":"e_1_2_10_17_1","doi-asserted-by":"publisher","DOI":"10.3390\/cancers13143549"},{"key":"e_1_2_10_18_1","doi-asserted-by":"publisher","DOI":"10.14316\/pmp.2016.27.4.258"},{"key":"e_1_2_10_19_1","volume-title":"Eclipse Proton Algorithms Reference Guide (P1026475\u2010002\u2010B)","author":"Varian Medical Systems","year":"2019"},{"key":"e_1_2_10_20_1","volume-title":"RayStation 11B RayPhysics Manual (RSL\u2010D\u2010RS\u201011B\u2010RPHY\u2010EN\u20101.0\u20102021\u201012\u201010)","author":"RaySearch LaboratoriesLaboratorie","year":"2021"},{"key":"e_1_2_10_21_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3683640"},{"key":"e_1_2_10_22_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.radonc.2021.03.016"},{"key":"e_1_2_10_23_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2017.09.043"},{"key":"e_1_2_10_24_1","doi-asserted-by":"publisher","DOI":"10.1002\/mp.12504"},{"key":"e_1_2_10_25_1","doi-asserted-by":"publisher","DOI":"10.1118\/1.3259742"},{"key":"e_1_2_10_26_1","doi-asserted-by":"publisher","DOI":"10.1002\/acm2.12043"}],"container-title":["Journal of Applied Clinical Medical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/acm2.14435","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,10,21]],"date-time":"2024-10-21T12:20:31Z","timestamp":1729513231000},"score":1,"resource":{"primary":{"URL":"https:\/\/aapm.onlinelibrary.wiley.com\/doi\/10.1002\/acm2.14435"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,6,23]]},"references-count":25,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2024,9]]}},"alternative-id":["10.1002\/acm2.14435"],"URL":"https:\/\/doi.org\/10.1002\/acm2.14435","archive":["Portico"],"relation":{},"ISSN":["1526-9914","1526-9914"],"issn-type":[{"value":"1526-9914","type":"print"},{"value":"1526-9914","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,6,23]]},"assertion":[{"value":"2024-03-04","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-06-04","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-06-23","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e14435"}}