To investigate the effectiveness of ultrasound in evaluating the degree of xerostomia in the patients with nasopharyngeal carcinoma (NPC) receiving intensity-modulated radiotherapy (IMRT).

A total of 30 NPC patients who were admitted to our hospital from May 2013 to December 2014 were enrolled in this study. The degree of xerostomia in these NPC patients was scored according to the Radiation Therapy Oncology Group scoring criteria. Color Doppler ultrasound was used to measure the peak systolic blood flow velocity of the parotid gland and submandibular gland and the changes in vascular diameter of the parotid gland in the NPC patients before, during, and after IMRT. The correlation between each parameter and the degree of xerostomia was determined by analysis of variance.

In the 28 NPC patients included in the statistical analysis, the degree of xerostomia during IMRT was significantly higher than that before IMRT (P=0.024), and the degree of xerostomia at 3 months after IMRT was significantly lower than that during IMRT (P=0.035). The peak systolic blood flow velocity of the parotid gland and submandibular gland and the proportion of patients with decreases in vascular diameter of the parotid gland during IMRT were significantly higher than those before IMRT (P=0.001 and 0.003; P=0.001); the above parameters at 3 months after IMRT were significantly lower than those during IMRT (P=0.008 and 0.012; P=0.001). During IMRT and after IMRT, the degree of xerostomia was significantly correlated with the peak systolic blood flow velocity of the parotid gland (r=0.563, P=0.026; r=0.409, P=0.031).

Ultrasound can be used as a noninvasive detection for the hemodynamic changes in the parotid gland, and it has a certain clinical reference value for evaluating the degree of xerostomia in NPC patients during and after IMRT.

Blood flow of parotid gland; Xerostomia; B ultrasound detection; Nasopharyngeal neoplasms/radiotherapy