Tehran University of Medical Sciences
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Davood Beiki

Does vitamin E protect salivary glands from I-131 radiation damage in patients with thyroid cancer

Authors: Fallahi B, Beiki D, Abedi SM, Saghari M, Fard-Esfahani A, Akhzari F, Mokarami B, Eftekhari M,
Nucl Med Commun, Vol.34, No.8, 2013,Page:777-786

Objectives: Salivary gland impairment after high-dose radioiodine (131I) 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 131I 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 131I: 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 131I 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 99mTc-pertechnetate in two phases, one immediately before and the other 6 months after 131I 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.