title: Silent aspiration and swallowing physiology after radiotherapy in patients with nasopharyngeal carcinoma.
abstract: BACKGROUND
  There is a paucity of knowledge on dysphagia in patients with nasopharyngeal carcinoma postradiotherapy (NPC post-RT). The purpose of this study was to establish silent aspiration occurrence, safe bolus consistency, and their relationship with swallowing physiology in patients with dysphagic NPC post-RT.
  
  
  METHODS
  Eighty-five patients with dysphagic NPC post-RT were assessed across 4 bolus consistencies. We compared penetration-aspiration scores against 4 swallowing physiology impairments.
  
  
  RESULTS
  Silent aspiration occurred in 65.9% of patients with dysphagia, with 64.7% on thin fluids, 35.3% on thick fluids, 11.8% on pureed diet, and 5.9% on soft diet. Multivariate analysis of variance (MANOVA) indicated pharyngeal contraction and swallowing response had significant effect on thick fluids (p = .002), thin fluids (p = .017), and soft diet (p = .031).
  
  
  CONCLUSIONS
  Silent aspiration of thin fluids is a common occurrence in dysphagic NPC post-RT, with least aspiration noted on soft diet. Considering the high incidence of silent aspiration, instrumental assessment in this cohort is crucial.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Administrative Region, China.
authors.forename: Louisa K Y
authors.initials: LK
authors.lastname: Ng
authors.forename: Kathy Y S
authors.initials: KY
authors.lastname: Lee
authors.forename: Sung Nok
authors.initials: SN
authors.lastname: Chiu
authors.forename: Peter K M
authors.initials: PK
authors.lastname: Ku
authors.forename: C Andrew
authors.initials: CA
authors.lastname: van Hasselt
authors.forename: Michael C F
authors.initials: MC
authors.lastname: Tong
mesh_terms: D002277:Carcinoma / Q000532:radiotherapy; D003680:Deglutition Disorders / Q000503:physiopathology*; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009303:Nasopharyngeal Neoplasms / Q000532:radiotherapy; D011878:Radiotherapy / Q000009:adverse effects*; D053120:Respiratory Aspiration / Q000503:physiopathology*; D012189:Retrospective Studies