Radiation-induced narrowing of the tracheobronchial tree: An in-depth analysis

Chris R. Kelsey, Daniel Kahn, Donna R. Hollis, Keith L. Miller, Su Min Zhou, Robert W. Clough, Lawrence B. Marks

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Purpose: Symptomatic narrowing of the tracheobronchial tree is not a common clinical problem after conventional-dose external beam radiation therapy but has been described when higher doses are utilized. This in-depth study quantifies changes in the caliber of the trachea and mainstem bronchi after high-dose external beam radiation therapy (EBRT). Methods and materials: As part of an IRB-approved prospective clinical trial to assess for radiation-induced lung injury, patients with thoracic malignancies had pre- and serial post-RT CT scans in the radiation oncology department. This report focuses on 18 enrolled patients who received high-dose (≥73.6 Gy) EBRT for NSCLC. The caliber of the trachea, right mainstem bronchus, and left mainstem bronchus were measured utilizing three-dimensional coordinates in axial and coronal planes such that multiple measurements were made of each structure. The decrease in airway caliber was tested for significance using a one-sided Wilcoxon matched-pairs signed-ranks test. The correlation between airway caliber changes, dose, and follow-up interval was tested using the Spearman rank correlation coefficient and the effect of chemotherapy on airway narrowing was evaluated with a one-sided exact Wilcoxon rank sum test. Results: There was no significant narrowing of the trachea for all dose and time points. There were significant decreases in the caliber of both mainstem bronchi on axial measurements (p = 0.07 and 0.005 for right and left mainstem bronchi, respectively). Decrease in airway caliber ranged from 6 to 57% and appeared to be dose dependent (p = 0.08), progressed with increasing time post-RT (p = 0.04), and was worse in patients who also received chemotherapy (p = 0.04). Conclusion: High-dose EBRT (≥73.6 Gy) appears to cause narrowing of the mainstem bronchi as early as 3 months post radiation therapy. Additional study is needed to assess the impact of such narrowing on RT-induced pulmonary symptoms.

Original languageEnglish (US)
Pages (from-to)111-116
Number of pages6
JournalLung Cancer
Issue number1
StatePublished - Apr 2006
Externally publishedYes


  • Bronchial stenosis
  • Dose escalation
  • External beam radiation therapy
  • Late effects
  • Lung cancer
  • Pulmonary complications

ASJC Scopus subject areas

  • Oncology
  • Pulmonary and Respiratory Medicine
  • Cancer Research

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