Evaluation of salivary function by sialoscintigraphy in locally advanced nasopharyngeal cancer patients after intensity modulated radiotherapy.

Purpose: This study aimed to evaluate the salivary gland function changes by sialoscintigraphy in locally advanced nasopharyngeal cancer (NPC) after intensity modulated radiotherapy (IMRT).
Materials and Methods: Salivary function was assessed by sialoscintigraphy. Quantitative sialoscintigraphy was performed in 24 NPC patients prior to and after IMRT. Results were categorized in four groups according to the duration of treatment. The sialoscintigraphy parameters were examined.
Results: Sialoscintigraphy showed a significant difference in the secretion of each interval groups. The parameters of scintigraphy, except maximum accumulation (MA) of submandibular glands, decreased first after radiotherapy, and then recovered. However, the MA of submandibular glands was continuously downhill after radiation.
Conclusions: The sialoscintigraphy parameters of each gland changed with the different radiation dose and follow-up intervals. The salivary function was influenced after radiotherapy in locally advanced NPC, especially, in the submandibular gland. Strategies to improve the salivary function should be assessed.