{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T19:09:04Z","timestamp":1792782544956,"version":"4.5.0"},"reference-count":26,"publisher":"Springer Science and Business Media LLC","license":[{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T00:00:00Z","timestamp":1789603200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Rheinische Friedrich-Wilhelms-Universit\u00e4t Bonn","id":[{"id":"https:\/\/ror.org\/041nas322","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Strahlenther Onkol"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>The optimal boost technique following breast-conserving surgery for patients with high-risk early breast cancer remains controversial. This study compared oncologic outcomes following an intraoperative radiotherapy (IORT) boost using low-energy X\u2011rays with those of a\u00a0conventional external beam radiotherapy (EBRT) boost in a\u00a0matched-pair cohort.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Patients treated with breast-conserving surgery followed by either an upfront IORT boost (20\u202fGy prescribed to the applicator surface) or a\u00a0postoperative EBRT boost (16\u202fGy in 8\u00a0fractions), sequentially after whole-breast radiotherapy, between 2014 and 2019 were retrospectively identified from a\u00a0prospectively maintained institutional database. Whole-breast irradiation was delivered after IORT using either conventional or moderately hypofractionated schedules according to institutional practice. The primary endpoint was ipsilateral breast tumour recurrence (IBTR). Secondary endpoints included nodal recurrence, distant metastasis, overall survival (OS), and breast cancer-specific survival (BCSS). Time-to-event outcomes were estimated using the Kaplan-Meier method, whereas treatment comparisons were performed using Cox proportional hazards regression with robust sandwich variance estimates clustered by matched pair.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Following 1:1\u00a0matching, 400 patients (200 per group) were included. After a\u00a0median follow-up of 58\u00a0months, the cumulative incidence of local recurrence was 3.5% and 2.0%, respectively, with no statistically significant difference between treatment groups (HR\u00a01.80, 95% CI 0.58\u20135.58;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u20090.312). Likewise, no significant differences were observed for nodal recurrence-free survival (HR\u00a00.98, 95% CI 0.19\u20135.16;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u20090.980), distant metastasis-free survival (HR\u00a00.92, 95% CI 0.38\u20132.23;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u20090.859), breast cancer-specific survival (HR\u00a00.79, 95% CI 0.30\u20132.10;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u20090.634), or overall survival (HR\u00a01.19, 95% CI 0.59\u20132.40;\n                      <jats:italic>p<\/jats:italic>\n                      \u202f=\u20090.636).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In this matched-pair analysis, an intraoperative low-energy X\u2011ray boost achieved oncologic outcomes comparable to those of a\u00a0conventional postoperative EBRT boost in patients undergoing breast-conserving therapy for high-risk early breast cancer. These findings support IORT boost as an effective and well-tolerated alternative that may simplify treatment delivery without compromising long-term oncologic outcomes.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1007\/s00066-026-02592-3","type":"journal-article","created":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T17:30:51Z","timestamp":1789666251000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Intraoperative or postoperative radiotherapy boost in high-risk breast cancer: a\u00a0matched-pair analysis"],"prefix":"10.1007","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5929-7270","authenticated-orcid":false,"given":"Gustavo R.","family":"Sarria","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cas","family":"Dejonckheere","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jorge","family":"Fernandez","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jose","family":"Burgos","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adela","family":"Heredia","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eleni","family":"Gkika","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gustavo J.","family":"Sarria","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paola","family":"Fuentes-Rivera","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,9,17]]},"reference":[{"key":"2592_CR1","doi-asserted-by":"publisher","first-page":"1227","DOI":"10.1056\/NEJMoa020989","volume":"347","author":"U Veronesi","year":"2002","unstructured":"Veronesi\u00a0U et\u00a0al (2002) Twenty-year follow-up of a\u00a0randomized study comparing breast-conserving surgery with radical mastectomy for early breast cancer. N Engl J Med 347:1227\u20131232","journal-title":"N Engl J Med"},{"key":"2592_CR2","doi-asserted-by":"publisher","first-page":"597","DOI":"10.1016\/S1470-2045(21)00080-2","volume":"22","author":"R Orecchia","year":"2021","unstructured":"Orecchia\u00a0R et\u00a0al (2021) Intraoperative irradiation for early breast cancer (ELIOT): long-term recurrence and survival outcomes from a single-centre, randomised, phase 3 equivalence trial. Lancet Oncol 22:597\u2013608","journal-title":"Lancet Oncol"},{"key":"2592_CR3","doi-asserted-by":"publisher","first-page":"47","DOI":"10.1016\/S1470-2045(14)71156-8","volume":"16","author":"H Bartelink","year":"2015","unstructured":"Bartelink\u00a0H et\u00a0al (2015) Whole-breast irradiation with or without a\u00a0boost for patients treated with breast-conserving surgery for early breast cancer: 20-year follow-up of a\u00a0randomised phase\u00a03\u00a0trial. Lancet Oncol 16:47\u201356","journal-title":"Lancet Oncol"},{"key":"2592_CR4","doi-asserted-by":"publisher","first-page":"1707","DOI":"10.1016\/S0140-6736(11)61629-2","volume":"378","author":"S Darby","year":"2011","unstructured":"Darby\u00a0S et\u00a0al (2011) Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet 378:1707\u20131716","journal-title":"Lancet"},{"key":"2592_CR5","doi-asserted-by":"crossref","unstructured":"Sperk, E. et\u00a0al. A\u00a0cohort analysis to identify eligible patients for intraoperative radiotherapy (IORT) of early breast cancer. Radiat Oncol\u00a09, (2014).","DOI":"10.1186\/1748-717X-9-154"},{"key":"2592_CR6","doi-asserted-by":"crossref","unstructured":"Kindts, I., Laenen, A., Depuydt, T. & Weltens, C.\u00a0Tumour bed boost radiotherapy for women after breast-conserving surgery. Cochrane Database Syst Rev\u00a011, (2017).","DOI":"10.1002\/14651858.CD011987.pub2"},{"key":"2592_CR7","doi-asserted-by":"publisher","first-page":"2124","DOI":"10.1016\/S0140-6736(23)00619-0","volume":"401","author":"CE Coles","year":"2023","unstructured":"Coles\u00a0CE et\u00a0al (2023) Dose-escalated simultaneous integrated boost radiotherapy in early breast cancer (IMPORT HIGH): a multicentre, phase 3, non-inferiority, open-label, randomised controlled trial. Lancet 401:2124\u20132137","journal-title":"Lancet"},{"key":"2592_CR8","doi-asserted-by":"crossref","unstructured":"Vicini, F. A. et\u00a0al. NRG RTOG 1005: A\u00a0Phase\u00a0III Trial of Hypo Fractionated Whole Breast Irradiation with Concurrent Boost vs. Conventional Whole Breast Irradiation Plus Sequential Boost Following Lumpectomy for High Risk Early-Stage Breast Cancer. 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Long-Term Outcomes of an International Cooperative Study of Intraoperative Radiotherapy Upfront Boost With Low Energy X\u2011Rays in Breast Cancer. Front Oncol\u00a012, (2022).","DOI":"10.3389\/fonc.2022.850351"},{"key":"2592_CR17","doi-asserted-by":"publisher","first-page":"2512","DOI":"10.1245\/s10434-020-09432-3","volume":"28","author":"SA Valente","year":"2021","unstructured":"Valente\u00a0SA et\u00a0al (2021) TARGIT\u2011R (Retrospective): 5\u2011Year Follow-Up Evaluation of Intraoperative Radiation Therapy (IORT) for Breast Cancer Performed in North America. Ann Surg Oncol 28:2512\u20132521","journal-title":"Ann Surg Oncol"},{"key":"2592_CR18","doi-asserted-by":"publisher","first-page":"349","DOI":"10.1007\/s00066-019-01525-7","volume":"196","author":"M Pez","year":"2020","unstructured":"Pez\u00a0M et\u00a0al (2020) Long-term outcome after intraoperative radiotherapy as a\u00a0boost in breast cancer. 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The study was conducted in accordance with the principles of the Declaration of Helsinki. No personal patient data are reported.","order":1,"name":"Ethics","label":"Ethical standards","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"G.R.\u00a0Sarria: personal fees, travel expenses, grants, speaker bureau and advisor\u2014Carl Zeiss Meditec AG. Personal fees and travel expenses\u2014AstraZeneca AG. Personal fees\u2014Roche AG. Personal fees and travel expenses\u2014MedWave Clinical Trials. Personal fees and travel expenses\u2014Guerbet SA. G.J.\u00a0Sarria: travel expenses and personal fees\u2014Carl Zeiss Meditec AG. C.\u00a0Dejonckheere, J.\u00a0Fernandez, J.\u00a0Burgos, A.\u00a0Heredia, E.\u00a0Gkika and P.\u00a0Fuentes-Rivera declare that they have no competing interests.","order":2,"name":"Ethics","label":"Conflict of interest","group":{"name":"EthicsHeading","label":"Declarations"}}]}}