Objectives: 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.
Copyright © 2013 Elsevier Inc. All rights reserved.