title: Dose to larynx predicts for swallowing complications after intensity-modulated radiotherapy.
abstract: OBJECTIVE
  To evaluate early swallowing after intensity-modulated radiotherapy for head and neck squamous cell carcinoma and determine factors correlating with aspiration and/or stricture.
  
  
  METHODS
  Consecutive patients treated with intensity-modulated radiotherapy with or without chemotherapy between September 2004 and August 2006 at the Dana Farber Cancer Institute/Brigham and Women's Hospital were evaluated with institutional review board approval. Patients underwent swallowing evaluation after completion of therapy; including video swallow studies. The clinical- and treatment-related variables were examined for correlation with aspiration or strictures, as well as doses to the larynx, pharyngeal constrictor muscles, and cervical esophagus. The correlation was assessed with logistic regression analysis.
  
  
  RESULTS
  A total of 96 patients were evaluated. Their median age was 55 years, and 79 (82%) were men. The primary site of cancer was the oropharynx in 43, hypopharynx/larynx in 17, oral cavity in 13, nasopharynx in 11, maxillary sinus in 2, and unknown primary in 10. Of the 96 patients, 85% underwent definitive RT and 15% postoperative RT. Also, 28 patients underwent induction chemotherapy followed by concurrent chemotherapy, 59 received concurrent chemotherapy, and 9 patients underwent RT alone. The median follow-up was 10 months. Of the 96 patients, 31 (32%) had clinically significant aspiration and 36 (37%) developed a stricture. The radiation dose-volume metrics, including the volume of the larynx receiving >or=50 Gy (p = 0.04 and p = 0.03, respectively) and volume of the inferior constrictor receiving >or=50 Gy (p = 0.05 and p = 0.02, respectively) were significantly associated with both aspiration and stricture. The mean larynx dose correlated with aspiration (p = 0.003). Smoking history was the only clinical factor to correlate with stricture (p = 0.05) but not aspiration.
  
  
  CONCLUSIONS
  Aspiration and stricture are common side effects after intensity-modulated radiotherapy for head-and-neck squamous cell carcinoma. The dose given to the larynx and inferior constrictors correlated with these side effects.
authors.affiliation: Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Hale B
authors.initials: HB
authors.lastname: Caglar
authors.forename: Roy B
authors.initials: RB
authors.lastname: Tishler
authors.forename: Megan
authors.initials: M
authors.lastname: Othus
authors.forename: Elaine
authors.initials: E
authors.lastname: Burke
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Laura
authors.initials: L
authors.lastname: Goguen
authors.forename: Lori J
authors.initials: LJ
authors.lastname: Wirth
authors.forename: Robert I
authors.initials: RI
authors.lastname: Haddad
authors.forename: Carl M
authors.initials: CM
authors.lastname: Norris
authors.forename: Laurence E
authors.initials: LE
authors.lastname: Court
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Aninno
authors.forename: Marshall R
authors.initials: MR
authors.lastname: Posner
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Allen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D003680:Deglutition Disorders / Q000175:diagnosis / Q000209:etiology*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications / Q000532:radiotherapy*; D006801:Humans; D007830:Larynx / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D009928:Organ Specificity; D011379:Prognosis; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016896:Treatment Outcome