title: Sensorineural hearing loss after concurrent chemoradiotherapy in nasopharyngeal cancer patients.
abstract: BACKGROUND
  Sensorineural hearing loss (SNHL) is one of the major long term side effects from radiation therapy (RT) in nasopharyngeal cancer (NPC) patients. This study aims to review the incidences of SNHL when treating with different radiation techniques. The additional objective is to determine the relationship of the SNHL with the radiation doses delivered to the inner ear.
  
  
  METHODS
  A retrospective cohort study of 134 individual ears from 68 NPC patients, treated with conventional RT and IMRT in combination with chemotherapy from 2004-2008 was performed. Dosimetric data of the cochlea were analyzed. Significant SNHL was defined as >15 dB increase in bone conduction threshold at 4 kHz and PTA (pure tone average of 0.5, 1, 2 kHz). Relative risk (RR) was used to determine the associated factors with the hearing threshold changes at 4 kHz and PTA.
  
  
  RESULTS
  Median audiological follow up time was 14 months. The incidence of high frequency (4 kHz) SNHL was 44% for the whole group (48.75% in the conventional RT, 37% with IMRT). Internal auditory canal mean dose of >50 Gy had shown a trend to increase the risk of high frequency SNHL (RR 2.02 with 95% CI 1.01-4.03, p=0.047).
  
  
  CONCLUSIONS
  IMRT and radiation dose limitation to the inner ear appeared to decrease SNHL.
authors.affiliation: Division of Radiation Oncology, Faculty of Medicine Siriraj Hospital, 2 Prannok Rd, Bangkoknoi, Bangkok, Thailand. sijps@mahidol.ac.th
authors.forename: Janjira
authors.initials: J
authors.lastname: Petsuksiri
authors.forename: Achariyaporn
authors.initials: A
authors.lastname: Sermsree
authors.forename: Kullathorn
authors.initials: K
authors.lastname: Thephamongkhol
authors.forename: Phawin
authors.initials: P
authors.lastname: Keskool
authors.forename: Kanthong
authors.initials: K
authors.lastname: Thongyai
authors.forename: Yaowalak
authors.initials: Y
authors.lastname: Chansilpa
authors.forename: Pittayapoom
authors.initials: P
authors.lastname: Pattaranutaporn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use; D002277:Carcinoma / Q000188:drug therapy* / Q000453:epidemiology / Q000532:radiotherapy*; D015331:Cohort Studies; D003131:Combined Modality Therapy / Q000009:adverse effects; D007758:Ear, Inner / Q000528:radiation effects; D006319:Hearing Loss, Sensorineural / Q000139:chemically induced / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects*; D012189:Retrospective Studies; D055815:Young Adult