title: Long-term sensorineural hearing deficit following radiotherapy in patients suffering from nasopharyngeal carcinoma: A prospective study.
abstract: BACKGROUND
  This was a prospective study to evaluate the effect of radical external irradiation on inner ear function after treatment of nasopharyngeal carcinoma.
  
  
  METHODS
  Pure tone audiograms were performed at regular intervals before, after, and up to 4.5 years following completion of radiotherapy.
  
  
  RESULTS
  Two hundred ninety-four patients (526 ears) were included. Within 3 months after radiotherapy, deterioration of bone conduction threshold at 4 kHz and pure tone average (average of 0.5 kHz, 1 kHz, and 2 kHz) were noted in 164 ears (31%) and 75 ears (14%), respectively. Patients older than 50 years and ears with threshold below 60 dB at 4 kHz before radiotherapy were significant factors (p < 0.01 and p < 0. 001) associated with a 4 kHz loss. In 40% of these ears, recovery was evident at 2 years. With follow-up for 4.5 years, the probability of significant threshold deterioration increased with time.
  
  
  CONCLUSIONS
  Sensorineural hearing loss started soon after radiotherapy. Early changes could be reversible while the probability of persistent hearing loss continued to increase.
authors.affiliation: Division of Otorhinolaryngology, Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: W K
authors.initials: WK
authors.lastname: Ho
authors.forename: W I
authors.initials: WI
authors.lastname: Wei
authors.forename: D L
authors.initials: DL
authors.lastname: Kwong
authors.forename: J S
authors.initials: JS
authors.lastname: Sham
authors.forename: P T
authors.initials: PT
authors.lastname: Tai
authors.forename: A P
authors.initials: AP
authors.lastname: Yuen
authors.forename: D K
authors.initials: DK
authors.lastname: Au
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000528:radiation effects; D001844:Bone Conduction / Q000528:radiation effects; D002277:Carcinoma / Q000188:drug therapy / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D016009:Chi-Square Distribution; D007758:Ear, Inner / Q000528:radiation effects; D005260:Female; D005500:Follow-Up Studies; D006319:Hearing Loss, Sensorineural / Q000209:etiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D011336:Probability; D011446:Prospective Studies; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D020127:Recovery of Function