Fig 7. Parotid volume versus xerostomia (7A) and parotid ADC versus xerostomia (7B) in nasopharyngeal carcinoma patients treated by intensity-modulated radiotherapy.

The parotid volume is significant lower in grades 1 and 2 as compared to grade 0 (P < .005). On the contrary, the parotid ADC was significant higher in grades 1 and 2 as compared to grade 0 (P < .005). Note: Grade 0 represents no symptom of dry mouth; grade 1 represents slight dryness of the mouth with good response on stimulation; grade 2 represents moderate dryness with poor response on stimulation.