title: Dose constraints to prevent radiation-induced brachial plexopathy in patients treated for lung cancer.
abstract: OBJECTIVE
  As the recommended radiation dose for non-small-cell lung cancer (NSCLC) increases, meeting dose constraints for critical structures like the brachial plexus becomes increasingly challenging, particularly for tumors in the superior sulcus. In this retrospective analysis, we compared dose-volume histogram information with the incidence of plexopathy to establish the maximum dose tolerated by the brachial plexus.
  
  
  METHODS
  We identified 90 patients with NSCLC treated with definitive chemoradiation from March 2007 through September 2010, who had received >55 Gy to the brachial plexus. We used a multiatlas segmentation method combined with deformable image registration to delineate the brachial plexus on the original planning CT scans and scored plexopathy according to Common Terminology Criteria for Adverse Events version 4.03.
  
  
  RESULTS
  Median radiation dose to the brachial plexus was 70 Gy (range, 56-87.5 Gy; 1.5-2.5 Gy/fraction). At a median follow-up time of 14.0 months, 14 patients (16%) had brachial plexopathy (8 patients [9%] had Grade 1, and 6 patients [7%] had Grade ≥2); median time to symptom onset was 6.5 months (range, 1.4-37.4 months). On multivariate analysis, receipt of a median brachial plexus dose of >69 Gy (odds ratio [OR] 10.091; 95% confidence interval [CI], 1.512-67.331; p = 0.005), a maximum dose of >75 Gy to 2 cm(3) of the brachial plexus (OR, 4.909; 95% CI, 0.966-24.952; p = 0.038), and the presence of plexopathy before irradiation (OR, 4.722; 95% CI, 1.267-17.606; p = 0.021) were independent predictors of brachial plexopathy.
  
  
  CONCLUSIONS
  For lung cancers near the apical region, brachial plexopathy is a major concern for high-dose radiation therapy. We developed a computer-assisted image segmentation method that allows us to rapidly and consistently contour the brachial plexus and establish the dose limits to minimize the risk of brachial plexopathy. Our results could be used as a guideline in future prospective trials with high-dose radiation therapy for unresectable lung cancer.
authors.affiliation: Department of Radiation Oncology, University of Texas M D Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Arya
authors.initials: A
authors.lastname: Amini
authors.forename: Jinzhong
authors.initials: J
authors.lastname: Yang
authors.forename: Ryan
authors.initials: R
authors.lastname: Williamson
authors.forename: Michelle L
authors.initials: ML
authors.lastname: McBurney
authors.forename: Jeremy
authors.initials: J
authors.lastname: Erasmus
authors.forename: Pamela K
authors.initials: PK
authors.lastname: Allen
authors.forename: Mandar
authors.initials: M
authors.lastname: Karhade
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Komaki
authors.forename: Zhongxing
authors.initials: Z
authors.lastname: Liao
authors.forename: Daniel
authors.initials: D
authors.lastname: Gomez
authors.forename: James
authors.initials: J
authors.lastname: Cox
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: James
authors.initials: J
authors.lastname: Welsh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001917:Brachial Plexus / Q000000981:diagnostic imaging / Q000528:radiation effects*; D020516:Brachial Plexus Neuropathies / Q000453:epidemiology / Q000517:prevention & control*; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011832:Radiation Injuries / Q000453:epidemiology / Q000517:prevention & control*; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D047368:Tumor Burden