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

Area of Science:

• Radiotherapy and Radiation Oncology
• Medical Imaging
• Head and Neck Cancer Treatment

Background:

• Radiation dose to the larynx can cause dysfunction.
• Current cross-sectional imaging lacks consistent guidelines for defining the larynx and its substructures.
• Accurate delineation of laryngeal organs-at-risk (OARs) is crucial for minimizing radiation-induced side effects.

Purpose of the Study:

• To develop and present standardized computed tomography (CT) and magnetic resonance imaging (MRI)-based guidelines for contouring laryngeal OARs.
• To establish reproducible methods for delineating laryngeal structures in head and neck cancer patients.

Main Methods:

• Standardized guidelines for delineating laryngeal OARs were created.
• Guidelines were applied to delineate OARs on CT and MRI scans of head and neck cancer patients.
• Volumetric comparisons were conducted to assess consistency and reproducibility of the contours.

Main Results:

• No significant difference in mean larynx volume was observed between CT and MRI modalities for initial patients.
• Laryngeal volumes showed no statistical difference between initial and subsequent patient cohorts on CT, or between CT and MRI scans.
• Volumes of laryngeal substructures were consistent across patients and imaging modalities.
• The developed guidelines were found to be easy to follow once established.

Conclusions:

• The developed guidelines offer a precise method for delineating laryngeal OARs on cross-sectional imaging.
• Further validation is required.
• Clinical significance and dose-volume constraints for laryngeal substructures need investigation before routine clinical implementation.