Development of a standardized method for contouring the larynx and its substructures

Radiat Oncol. 2014 Dec 11;9:285. doi: 10.1186/s13014-014-0285-4.

Abstract

Objectives: Limiting radiation dose to the larynx can diminish effects of laryngeal dysfunction. However, no clear guidelines exist for defining the larynx and its substructures consistently on cross-sectional imaging. This study presents computed tomography (CT)- and magnetic resonance imaging (MRI)-based guidelines for contouring laryngeal organs-at-risk (OARs).

Materials and methods: Standardized guidelines for delineating laryngeal OARs were devised and used to delineate on CT and MRI for head-and-neck cancer patients. Volumetric comparisons were performed to evaluate consistency and reproducibility of guideline-based contours.

Results: For the initial 5 patients the mean CT and MRI based larynx volume did not differ significantly between imaging modalities; 34.39 ± 9.85 vs. 35.01 ± 9.47 (p = .09). There was no statistical difference between the CT based mean laryngeal volume in the subsequent 44 patients compared to the initial 5 patients outlined on CT and the MRI scan (p = 0.53 and 0.62). The OAR volume for laryngeal substructures were not statistically different among patients or between imaging modalities. Once established, the guidelines were easy to follow.

Conclusion: The guidelines developed provide a precise method for delineating laryngeal OARs. These guidelines need to be validated and clinical significance of outlining laryngeal substructures and dose-volume constraints should be investigated before routine implementation in clinic practice.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Atlases as Topic
  • Carcinoma, Squamous Cell / radiotherapy*
  • Female
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Imaging, Three-Dimensional / methods
  • Imaging, Three-Dimensional / standards
  • Larynx / anatomy & histology*
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Multimodal Imaging / methods
  • Multimodal Imaging / standards
  • Organs at Risk / anatomy & histology*
  • Radiation Injuries / prevention & control*
  • Radiotherapy Planning, Computer-Assisted / methods
  • Radiotherapy Planning, Computer-Assisted / standards*
  • Squamous Cell Carcinoma of Head and Neck
  • Tomography, X-Ray Computed