title: Permanent unilateral hearing loss after radiotherapy for parotid gland tumors.
abstract: BACKGROUND
  The purpose of this retrospective study was to determine the long-term effects of radiotherapy on hearing function in patients who underwent parotidectomy and postoperative radiotherapy for unilateral tumors of the parotid gland.
  
  
  METHODS
  An extensive set of tests was used to measure hearing loss. The mean dose on middle ear, cochlea, and Eustachian tube was estimated with a CT-planning system.
  
  
  RESULTS
  A hearing loss of > or = 15 dB in 3 frequencies was found in 32% of the 52 patients included in the study. Patients with an asymmetrical hearing loss received a higher mean dose on the hearing structures (p < .002). The threshold dose for clinically relevant hearing loss was found at 50 Gy on the cochlea and Eustachian tube.
  
  
  CONCLUSIONS
  Radiation-induced hearing loss is a common complication. A mean dose of > 50 Gy on the cochlea should be avoided.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, VU University Medical Center, de Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
authors.forename: Lisa
authors.initials: L
authors.lastname: van der Putten
authors.forename: Remco
authors.initials: R
authors.lastname: de Bree
authors.forename: John T
authors.initials: JT
authors.lastname: Plukker
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Langendijk
authors.forename: Cas
authors.initials: C
authors.lastname: Smits
authors.forename: Fred R
authors.initials: FR
authors.lastname: Burlage
authors.forename: C René
authors.initials: CR
authors.lastname: Leemans
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001299:Audiometry; D005260:Female; D046088:Hearing Loss, Unilateral / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000601:surgery; D010307:Parotid Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D011182:Postoperative Care; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D012189:Retrospective Studies