Salivary gland scintigraphy in evaluating parotid function of patients with nasopharyngeal carcinoma after radiotherapy

Objective To study the feasibility of salivary gland scintigraphy in evaluating parotid function of patients with nasopharyngeal carcinoma(NPC) after radiotherapy.Methods Forty patients with NPC who underwent intensity-modulation radiation therapy 30cases(IMRT) or conventional radiotherapy 10 cases were observed.The level of mouth dryness and parotid function before IMRT,at the end of IMRT and 5 month after IMRT were compared by each other.Results Different degrees of mouth dryness were common at the end of IMRT among the patients,but some of them recovered significantly 5 month after IMRT.The parotid scintigraphy signs between before and after IMRT were different,both of uptake index(UI) and excretion index(EI) after IMRT were significant lower than those of before IMRT(P0.05).However,the UI and EI of the patients treated with IMRT were significantly higher than those treated with conventional radiotherapy(P0.05).Conclusions IMRT can effectively protect parotid function.Salivary gland scintigraphy is sensitive and feasible for monitoring parotid function of NPC patients after radiotherapy.