Dosimetric factors associated with long-term dysphagia after definitive radiotherapy for squamous cell carcinoma of the head and neck

Int J Radiat Oncol Biol Phys. 2010 Feb 1;76(2):403-9. doi: 10.1016/j.ijrobp.2009.02.017. Epub 2009 May 19.

Abstract

Purpose: Intensification of radiotherapy and chemotherapy for head-and-neck cancer may lead to increased rates of dysphagia. Dosimetric predictors of objective findings of long-term dysphagia were sought.

Methods and materials: From an institutional database, 83 patients were identified who underwent definitive intensity-modulated radiotherapy for squamous cell carcinoma of the head and neck, after exclusion of those who were treated for a second or recurrent head-and-neck primary lesion, had locoregional recurrence at any time, had less than 12 months of follow-up, or had postoperative radiotherapy. Dosimetric parameters were analyzed relative to three objective endpoints as a surrogate for severe long-term dysphagia: percutaneous endoscopic gastrostomy (PEG) tube dependence at 12 months, aspiration on modified barium swallow, or pharyngoesophageal stricture requiring dilation.

Results: Mean dose greater than 41 Gy and volume receiving 60 Gy (V(60)) greater than 24% to the larynx were significantly associated with PEG tube dependence and aspiration. V(60) greater than 12% to the inferior pharyngeal constrictor was also significantly associated with increased PEG tube dependence and aspiration. V(65) greater than 33% to the superior pharyngeal constrictor or greater than 75% to the middle pharyngeal constrictor was associated with pharyngoesophageal stricture requiring dilation.

Conclusions: Doses to the larynx and pharyngeal constrictors predicted long-term swallowing complications, even when controlled for other clinical factors. The addition of these structures to intensity-modulated radiotherapy optimization may reduce the incidence of dysphagia, although cautious clinical validation is necessary.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Carcinoma, Squamous Cell / drug therapy
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / radiotherapy*
  • Catheterization / statistics & numerical data
  • Deglutition
  • Deglutition Disorders / etiology*
  • Esophageal Stenosis / etiology
  • Esophageal Stenosis / therapy
  • Female
  • Gastrostomy / statistics & numerical data
  • Head and Neck Neoplasms / drug therapy
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Male
  • Middle Aged
  • Pharyngeal Diseases / etiology
  • Pharyngeal Diseases / therapy
  • Radiotherapy Dosage
  • Radiotherapy, Intensity-Modulated / adverse effects*
  • Retrospective Studies
  • Tumor Burden
  • Young Adult