title: Dysphagia in head and neck cancer patients following intensity modulated radiotherapy (IMRT).
abstract: BACKGROUND
  To evaluate the objective and subjective long term swallowing function, and to relate dysphagia to the radiation dose delivered to the critical anatomical structures in head and neck cancer patients treated with intensity modulated radiation therapy (IMRT, +/- chemotherapy), using a midline protection contour (below hyoid, ~level of vertebra 2/3).
  
  
  METHODS
  82 patients with stage III/IV squamous cell carcinoma of the larynx, oropharynx, or hypopharynx, who underwent successful definitive (n = 63, mean dose 68.9Gy) or postoperative (n = 19, mean dose 64.2Gy) simultaneous integrated boost (SIB) -IMRT either alone or in combination with chemotherapy (85%) with curative intent between January 2002 and November 2005, were evaluated retrospectively. 13/63 definitively irradiated patients (21%) presented with a total gross tumor volume (tGTV) >70cc (82-173cc; mean 106cc). In all patients, a laryngo-pharyngeal midline sparing contour outside of the PTV was drawn. Dysphagia was graded according subjective patient-reported and objective observer-assessed instruments. All patients were re-assessed 12 months later. Dose distribution to the swallowing structures was calculated.
  
  
  RESULTS
  At the re-assessment, 32-month mean post treatment follow-up (range 16-60), grade 3/4 objective toxicity was assessed in 10%. At the 32-month evaluation as well as at the last follow up assessment mean 50 months (16-85) post-treatment, persisting swallowing dysfunction grade 3 was subjectively and objectively observed in 1 patient (1%). The 5-year local control rate of the cohort was 75%; no medial marginal failures were observed.
  
  
  CONCLUSIONS
  Our results show that sparing the swallowing structures by IMRT seems effective and relatively safe in terms of avoidance of persistent grade 3/4 late dysphagia and local disease control.
authors.affiliation: Department of Radiation Oncology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Peponi
authors.forename: Christoph
authors.initials: C
authors.lastname: Glanzmann
authors.forename: Bettina
authors.initials: B
authors.lastname: Willi
authors.forename: Gerhard
authors.initials: G
authors.lastname: Huber
authors.forename: Gabriela
authors.initials: G
authors.lastname: Studer
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000532:radiotherapy*; D003680:Deglutition Disorders / Q000453:epidemiology / Q000209:etiology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000453:epidemiology / Q000209:etiology*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors