{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T17:52:38Z","timestamp":1790963558397,"version":"4.1.0"},"reference-count":21,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T00:00:00Z","timestamp":1790899200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Background\/Objectives: Tumours abutting or involving the brachial plexus can cause pain and neurological deficits. We evaluated six-fraction ultra-hypofractionated radiotherapy with a simultaneous integrated boost (uhRT-SIB) in a predominantly palliative cohort. Methods: We retrospectively analysed consecutive patients treated from April 2022 to June 2026, with a data cut-off of 7 July 2026. Image-guided VMAT delivered 33 Gy and 24 Gy to the high- and lower-dose planning target volumes, respectively. Outcomes included the best documented CTCAE-based symptom response, study-defined volumetric response (&gt;30% GTV reduction), freedom from local progression (FFLP), overall survival (OS), and neurological findings in routine clinical records. Results: Forty-four patients with 45 lesions were treated; 29\/45 lesions (64.4%) contacted the plexus. The median observed follow-up was 7.8 months (range 0.6\u201340.6). Symptoms improved by at least one grade in 16\/19 evaluable symptomatic patients (84.2%, 95% CI 62.4\u201394.5%). The median times to first documented benefit and best symptom grade among responders were 9 and 23 days. The first-scan volumetric response occurred in 24\/30 evaluable lesions (80.0%, 95% CI 62.7\u201390.5%). Six- and 12-month FFLP were 84.7% (95% CI 63.9\u201394.0%) and 73.7% (95% CI 49.7\u201387.6%), respectively. The median OS was 9.6 months. No clinical diagnosis of radiation-induced brachial plexopathy was documented; neurological assessment was not standardised. Conclusions: In this predominantly palliative cohort, six-fraction uhRT-SIB was associated with symptom improvement in 84.2% of evaluable symptomatic patients, study-defined volumetric response in 80.0% of evaluable lesions, and 12-month FFLP of 73.7%. No clinical diagnosis of radiation-induced brachial plexopathy was documented during routine follow-up, although the assessment of late neurological toxicity was limited.<\/jats:p>","DOI":"10.3390\/cancers18193189","type":"journal-article","created":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T16:50:38Z","timestamp":1790959838000},"page":"3189","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Six-Fraction Ultra-Hypofractionated Radiotherapy for Tumours Adjacent to or Involving the Brachial Plexus: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-7505-7240","authenticated-orcid":false,"given":"Maximilian","family":"Sturz","sequence":"first","affiliation":[{"name":"Department of Radiation Oncology, University Teaching Hospital Luzern, Spitalstrasse, 6004 Luzern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8780-7701","authenticated-orcid":false,"given":"Gabriela","family":"Studer","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University Teaching Hospital Luzern, Spitalstrasse, 6004 Luzern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"given":"Christoph","family":"Glanzmann","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University Teaching Hospital Luzern, Spitalstrasse, 6004 Luzern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3996-7043","authenticated-orcid":false,"given":"Sergejs","family":"Unterkirhers","sequence":"additional","affiliation":[{"name":"Medical Physics, Radiotherapy Hirslanden, Witellikerstrasse 40, 8032 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"given":"Philippe","family":"Logaritsch","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University Teaching Hospital Luzern, Spitalstrasse, 6004 Luzern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-8746-3814","authenticated-orcid":false,"given":"Olga","family":"Unterkirhere","sequence":"additional","affiliation":[{"name":"Department of Radiation Oncology, University Teaching Hospital Luzern, Spitalstrasse, 6004 Luzern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,2]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/S0733-8619(18)30253-6","article-title":"Nerve plexus metastases","volume":"9","author":"Jaeckle","year":"1991","journal-title":"Neurol. 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