{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,10]],"date-time":"2026-10-10T14:59:55Z","timestamp":1791644395411,"version":"4.3.4"},"reference-count":32,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T00:00:00Z","timestamp":1779408000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>This study aimed to compare the dosimetric differences between the use of range shifter and bolus in spot-scanning proton arc (SPArc) therapy for postoperative radiotherapy after left-sided breast cancer modified radical mastectomy, with a primary focus on target volume dose coverage and organs-at-risk sparing. By comparison with VMAT, this study further explored the potential of SPArc to reduce the normal tissue complication probability (NTCP) and the effective dose to immune cells (EDIC).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>This retrospective study utilized the imaging datasets of 18 patients who treated with VMAT. Three SPArc plans were designed for each patient using the RayStation v2025: 1. SPArc with bolus (SPArcB); 2. SPArc with range shifter (SPArcR); 3. SPArc with both bolus and range shifter (SPArcRB). The target volumes included the supraclavicular target volume and the chest wall target volume. The Lyman\u2013Kutcher\u2013Birman NTCP model was adopted to evaluate pulmonary and cardiac toxicities and the EDIC model was applied to assess the immune cell dose across different plans. Robustness optimization accounting for a\u202f\u00b1\u202f3.5% range uncertainty and a 5\u202fmm setup error was incorporated into all SPArc treatment plans.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>All SPArc plans met robustness criteria and significantly reduced doses to the heart and left lung, as well as EDIC, compared to VMAT. The SPArcR plan demonstrated superior cardiac protection, achieving the lowest mean heart dose and the most significant reduction in NTCP for both the heart and lungs. While SPArcB showed a slight advantage in reducing the mean left lung dose, SPArcR yielded the highest conformity index for target coverage.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>This study confirms that, in postoperative radiotherapy for left-sided breast cancer after modified radical mastectomy, the standalone application of a range shifter can optimally reduce cardiac dose and the associated risk of complications while ensuring adequate target volume coverage, and it circumvents the issues of setup variability and hygiene concerns associated with the clinical use of bolus.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fpubh.2026.1773124","type":"journal-article","created":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T06:11:43Z","timestamp":1779430303000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["A study on the application of range shifter and bolus in spot-scanning proton arc (SPArc) therapy after modified radical mastectomy for left-sided breast cancer"],"prefix":"10.3389","volume":"14","author":[{"given":"Linsen","family":"Zhou","sequence":"first","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yiwen","family":"He","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shiyan","family":"Shen","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaobin","family":"Wang","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuokai","family":"Jia","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hexiang","family":"Feng","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinjian","family":"Yang","sequence":"additional","affiliation":[{"name":"Sichuan University","place":["Chengdu, China"]},{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xianhu","family":"Zeng","sequence":"additional","affiliation":[{"name":"Department of Radiotherapy Physics & Technology, West China Hospital, Sichuan University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,22]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"229","DOI":"10.3322\/caac.21834","article-title":"Global cancer statistics 2022: globocan estimates of incidence and mortality worldwide for 36 cancers in 185 countries","volume":"74","author":"Bray","year":"2024","journal-title":"CA Cancer J Clin"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"259","DOI":"10.21147\/j.issn.1000-9604.2019.02.02","article-title":"National guidelines for diagnosis and treatment of breast cancer 2022 in China (English version)","volume":"31","year":"2022","journal-title":"Chin J Cancer Res"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"2091171656","DOI":"10.1177\/15330338211053752","article-title":"Cardiac dose control and optimization strategy for left breast cancer radiotherapy with non-uniform VMAT technology","volume":"20","author":"Qiu","year":"2021","journal-title":"Technol Cancer Res Treat"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"55","DOI":"10.1016\/j.canrad.2020.05.017","article-title":"Radioth\u00e9rapie et toxicit\u00e9 m\u00e9dullaire: actualit\u00e9s et perspectives. [Radiotherapy and spinal toxicity: news and perspectives]","volume":"25","author":"Peyraga","year":"2021","journal-title":"Cancer Radiother"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"150","DOI":"10.1016\/j.chest.2019.03.033","article-title":"Radiation-induced lung injury: assessment and management","volume":"156","author":"Hanania","year":"2019","journal-title":"Chest"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"730","DOI":"10.1080\/0284186X.2017.1299218","article-title":"Model-based approach for quantitative estimates of skin, heart, and lung toxicity risk for left-side photon and proton irradiation after breast-conserving surgery","volume":"56","author":"Tommasino","year":"2017","journal-title":"Acta Oncol"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1107","DOI":"10.1016\/j.ijrobp.2016.08.049","article-title":"Spot-scanning proton arc (SPArc) therapy: the first robust and delivery-efficient spot-scanning proton arc therapy","volume":"96","author":"Ding","year":"2016","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"1305","DOI":"10.1002\/mp.16098","article-title":"Spot scanning proton arc therapy reduces toxicity in oropharyngeal cancer patients","volume":"50","author":"de Jong","year":"2023","journal-title":"Med Phys"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"104816","DOI":"10.1016\/j.ejmp.2024.104816","article-title":"Investigate potential clinical benefits and linear energy transfer sparing utilizing proton arc therapy for hepatocellular carcinoma","volume":"126","author":"Liu","year":"2024","journal-title":"Phys Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"199","DOI":"10.1016\/j.ijrobp.2016.01.044","article-title":"An analysis of plan robustness for esophageal tumors: comparing volumetric modulated arc therapy plans and spot scanning proton planning","volume":"95","author":"Warren","year":"2016","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"232","DOI":"10.1186\/s13014-020-01676-3","article-title":"Feasibility study: spot-scanning proton arc therapy (SPArc) for left-sided whole breast radiotherapy","volume":"15","author":"Chang","year":"2020","journal-title":"Radiat Oncol"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"154","DOI":"10.1118\/1.3259742","article-title":"Commissioning of the discrete spot scanning proton beam delivery system at the University of Texas M.D. Anderson cancer center, proton therapy center, Houston","volume":"37","author":"Gillin","year":"2010","journal-title":"Med Phys"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1016\/j.radonc.2021.09.012","article-title":"A delphi study and international consensus recommendations: the use of bolus in the setting of postmastectomy radiation therapy for early breast cancer","volume":"164","author":"Kaidar-Person","year":"2021","journal-title":"Radiother Oncol"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"1151","DOI":"10.1080\/0284186X.2020.1826573","article-title":"RBE for proton radiation therapy\u2014a nordic view in the international perspective","volume":"59","author":"Toma-Dasu","year":"2020","journal-title":"Acta Oncol"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"1335","DOI":"10.1118\/1.4908208","article-title":"Impact of range shifter material on proton pencil beam spot characteristics","volume":"42","author":"Shen","year":"2015","journal-title":"Med Phys"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"103938","DOI":"10.1016\/j.clon.2025.103938","article-title":"Evaluation of radiotherapy plan robustness: a systematic literature review","volume":"48","author":"Kim","year":"2025","journal-title":"Clin Oncol (R Coll Radiol)"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"555","DOI":"10.1016\/j.canrad.2011.04.003","article-title":"State of the art on dose prescription, reporting and recording in intensity-modulated radiation therapy (ICRU report no. 83)","volume":"15","author":"Gr\u00e9goire","year":"2011","journal-title":"Cancer Radiother"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"724","DOI":"10.1016\/s0360-3016(02)03986-x","article-title":"Comparing different NTCP models that predict the incidence of radiation pneumonitis. Normal tissue complication probability","volume":"55","author":"Seppenwoolde","year":"2003","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"18166","DOI":"10.1038\/s41598-021-97605-9","article-title":"Mean heart dose-based normal tissue complication probability model for pericardial effusion: a study in oesophageal cancer patients","volume":"11","author":"Fukada","year":"2021","journal-title":"Sci Rep"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"6193","DOI":"10.3390\/cancers13246193","article-title":"Higher radiation dose to the immune cells correlates with worse tumor control and overall survival in patients with stage III NSCLC: a secondary analysis of RTOG0617","volume":"13","author":"Jin","year":"2021","journal-title":"Cancers (Basel)"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"768956","DOI":"10.3389\/fonc.2022.768956","article-title":"Radiation induced lymphopenia is associated with the effective dose to the circulating immune cells in breast cancer","volume":"12","author":"Chen","year":"2022","journal-title":"Front Oncol"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"164","DOI":"10.1002\/acm2.12241","article-title":"Quantifying the effect of air gap, depth, and range shifter thickness on TPS dosimetric accuracy in superficial PBS proton therapy","volume":"19","author":"Shirey","year":"2018","journal-title":"J Appl Clin Med Phys"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"101478","DOI":"10.1016\/j.adro.2024.101478","article-title":"Dosimetric comparison of CPAP and DIBH for left-sided breast cancer radiation therapy","volume":"9","author":"Choi","year":"2024","journal-title":"Adv Radiat Oncol"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"299","DOI":"10.1007\/s12282-019-01023-9","article-title":"Meta-analysis of deep inspiration breath hold (DIBH) versus free breathing (FB) in postoperative radiotherapy for left-side breast cancer","volume":"27","author":"Lai","year":"2020","journal-title":"Breast Cancer"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"e377","DOI":"10.1016\/j.prro.2017.06.006","article-title":"Postmastectomy radiation therapy technique and cardiopulmonary sparing: a dosimetric comparative analysis between photons and protons with free breathing versus deep inspiration breath hold","volume":"7","author":"Patel","year":"2017","journal-title":"Pract Radiat Oncol"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"1032","DOI":"10.3109\/0284186X.2015.1011756","article-title":"Proton beam versus photon beam dose to the heart and left anterior descending artery for left-sided breast cancer","volume":"54","author":"Lin","year":"2015","journal-title":"Acta Oncol"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"105774","DOI":"10.1016\/j.ejmp.2026.105774","article-title":"Dosimetric comparison of intensity modulated proton therapy and knowledge-based volumetric arc therapy for left-sided breast cancer","volume":"145","author":"Huynh","year":"2026","journal-title":"Phys Med"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"56","DOI":"10.2340\/1651-226X.2024.28591","article-title":"Spot-scanning proton therapy for early breast cancer in free breathing versus deep inspiration breath-hold","volume":"63","author":"Stick","year":"2024","journal-title":"Acta Oncol"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"103782","DOI":"10.1016\/j.clon.2025.103782","article-title":"A systematic review of deep inspiration breath hold and free breathing in proton beam therapy plans for breast cancer radiotherapy","volume":"40","author":"Wilson","year":"2025","journal-title":"Clin Oncol (R Coll Radiol)"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"749","DOI":"10.1002\/acm2.12416","article-title":"Redefine the role of range shifter in treating bilateral head and neck cancer in the era of intensity modulated proton therapy","volume":"19","author":"Ding","year":"2018","journal-title":"J Appl Clin Med Phys"},{"key":"ref31","doi-asserted-by":"publisher","DOI":"10.1088\/1361-6560\/aca874","article-title":"Introduce a rotational robust optimization framework for spot-scanning proton arc (sparc) therapy","volume":"68","author":"Chang","year":"2022","journal-title":"Phys Med Biol"},{"key":"ref32","doi-asserted-by":"publisher","first-page":"110653","DOI":"10.1016\/j.radonc.2024.110653","article-title":"Evaluating and reporting LET and RBE-weighted dose in proton therapy for glioma\u2014the dutch approach","volume":"202","author":"Wagenaar","year":"2025","journal-title":"Radiother Oncol"}],"container-title":["Frontiers in Public Health"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2026.1773124\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,22]],"date-time":"2026-05-22T06:11:46Z","timestamp":1779430306000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2026.1773124\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,22]]},"references-count":32,"alternative-id":["10.3389\/fpubh.2026.1773124"],"URL":"https:\/\/doi.org\/10.3389\/fpubh.2026.1773124","relation":{},"ISSN":["2296-2565"],"issn-type":[{"value":"2296-2565","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,22]]},"article-number":"1773124"}}