title: Analysis of factors influencing the development of xerostomia during intensity-modulated radiotherapy.
abstract: OBJECTIVE
  Factors influencing xerostomia during intensity-modulated radiation therapy (IMRT) were assessed.
  
  
  METHODS
  A 6-week study of 32 head and neck cancer (HNC) patients was performed. Subjects completed the Xerostomia Inventory (XI) and provided stimulated saliva (SS) at baseline, week 2 and at end of IMRT. Influence of SS flow rate (SSFR), calcium and mucin 5b (MUC5b) concentrations and radiation dose on xerostomia was determined.
  
  
  RESULTS
  HNC subjects experienced mean SSFR decline of 36% by visit 2 (N = 27; P = .012) and 57% by visit 3 (N = 20; P = .0004). Concentrations of calcium and MUC5b increased, but not significantly during IMRT (P > .05). Xerostomia correlated most with decreasing salivary flow rate as determined by Spearman correlations (P < .04) and linear mixed models (P < .0001).
  
  
  CONCLUSIONS
  Although IMRT is sparing to the parotid glands, it has an early effect on SSFR and the constituents in saliva in a manner that is associated with the perception of xerostomia.
authors.affiliation: Department of Oral Health Practice, Division of Oral Medicine, Center for Oral Health Research, College of Dentistry, University of Kentucky, Lexington, KY, USA.
authors.forename: Ken
authors.initials: K
authors.lastname: Randall
authors.forename: Jason
authors.initials: J
authors.lastname: Stevens
authors.forename: Juan Fernando
authors.initials: JF
authors.lastname: Yepes
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Randall
authors.forename: Mahesh
authors.initials: M
authors.lastname: Kudrimoti
authors.forename: Jonathan
authors.initials: J
authors.lastname: Feddock
authors.forename: Jing
authors.initials: J
authors.lastname: Xi
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kryscio
authors.forename: Craig S
authors.initials: CS
authors.lastname: Miller
mesh_terms: D000328:Adult; D000368:Aged; D002118:Calcium / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D055257:Mucin-5B / Q000032:analysis*; D011878:Radiotherapy / Q000009:adverse effects / Q000379:methods; D012463:Saliva / Q000737:chemistry*; D011795:Surveys and Questionnaires; D014987:Xerostomia / Q000175:diagnosis / Q000209:etiology*
chemical_list: D055257:Mucin-5B; D002118:Calcium