Nucl Med Commun. 2013 (May 23) [Epub ahead of print]
Fallahi B, Beiki D, Abedi SM, Saghari M, Fard-Esfahani A,
Akhzari F, Mokarami B, Eftekhari M.
Research Center for Nuclear Medicine,
Tehran University of Medical Sciences,
OBJECTIVES: Salivary gland impairment after high-dose radioiodine (I) treatment is well recognized. The aim of this study was to determine the protective effect of vitamin E on radiation-induced salivary gland dysfunction in patients undergoing I treatment for differentiated thyroid cancer.
METHODS: Thirty-six patients with differentiated thyroid carcinoma were enrolled in this study. They were randomly divided into two groups before postsurgical ablation therapy with 3700-5550 MBq I: the control group, comprising 17 patients, and the vitamin E group, comprising 19 patients. All 19 patients in the experimental group received vitamin E at a dose of 800 IU/day for a duration of 1 week before to 4 weeks after I therapy and the 17 patients in the control group received a placebo for the same duration. Salivary gland function was assessed using salivary gland scintigraphy with intravenous injection of 370 MBq Tc-pertechnetate in two phases, one immediately before and the other 6 months after I ablative therapy. First-minute uptake ratio, maximum uptake ratio, maximum secretion percentage, and excretion fraction (EF) of each salivary gland were measured and compared between the study phases for the two groups.
RESULTS: There was no significant difference between preablative and postablative salivary scintigraphic indices in the experimental vitamin E group, whereas maximum secretion percentage and EF of the right submandibular gland and EF of the left parotid gland were significantly decreased in the control group. There was also a higher significant decrease in the EF of the left parotid gland in the control group compared with the vitamin E group.
CONCLUSION: Vitamin E consumption may be associated with a significant protective effect against radiation-induced dysfunction in salivary glands following single-dose I therapy in patients with differentiated thyroid cancer.