title: Brachial plexus-associated neuropathy after high-dose radiation therapy for head-and-neck cancer.
abstract: OBJECTIVE
  To identify clinical and treatment-related predictors of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer.
  
  
  METHODS
  Three hundred thirty patients who had previously completed radiation therapy for head-and-neck cancer were prospectively screened using a standardized instrument for symptoms of neuropathy thought to be related to brachial plexus injury. All patients were disease-free at the time of screening. The median time from completion of radiation therapy was 56 months (range, 6-135 months). One-hundred fifty-five patients (47%) were treated by definitive radiation therapy, and 175 (53%) were treated postoperatively. Radiation doses ranged from 50 to 74 Gy (median, 66 Gy). Intensity-modulated radiation therapy was used in 62% of cases, and 133 patients (40%) received concurrent chemotherapy.
  
  
  RESULTS
  Forty patients (12%) reported neuropathic symptoms, with the most common being ipsilateral pain (50%), numbness/tingling (40%), motor weakness, and/or muscle atrophy (25%). When patients with <5 years of follow-up were excluded, the rate of positive symptoms increased to 22%. On univariate analysis, the following factors were significantly associated with brachial plexus symptoms: prior neck dissection (p = 0.01), concurrent chemotherapy (p = 0.01), and radiation maximum dose (p < 0.001). Cox regression analysis confirmed that both neck dissection (p < 0.001) and radiation maximum dose (p < 0.001) were independently predictive of symptoms.
  
  
  CONCLUSIONS
  The incidence of brachial plexus-associated neuropathies after radiation therapy for head-and-neck cancer may be underreported. In view of the dose-response relationship identified, limiting radiation dose to the brachial plexus should be considered when possible.
authors.affiliation: Department of Radiation Oncology, University of California, Davis School of Medicine, Sacramento, California, USA. allen.chen@ucdmc.ucdavis.edu
authors.forename: Allen M
authors.initials: AM
authors.lastname: Chen
authors.forename: William H
authors.initials: WH
authors.lastname: Hall
authors.forename: Judy
authors.initials: J
authors.lastname: Li
authors.forename: Laurel
authors.initials: L
authors.lastname: Beckett
authors.forename: D Gregory
authors.initials: DG
authors.lastname: Farwell
authors.forename: Derick H
authors.initials: DH
authors.lastname: Lau
authors.forename: James A
authors.initials: JA
authors.lastname: Purdy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001917:Brachial Plexus / Q000528:radiation effects*; D020516:Brachial Plexus Neuropathies / Q000175:diagnosis / Q000209:etiology*; D059248:Chemoradiotherapy / Q000009:adverse effects / Q000706:statistics & numerical data; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D037981:Neck Dissection / Q000009:adverse effects; D009367:Neoplasm Staging / Q000145:classification; D058958:Organs at Risk / Q000528:radiation effects; D011446:Prospective Studies; D011832:Radiation Injuries / Q000150:complications*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects* / Q000706:statistics & numerical data; D012044:Regression Analysis; D012307:Risk Factors