Radioprotection of salivary glands by amifostine in high-dose radioiodine treatment - Results of a double-blinded, placebo-controlled study in patients with differentiated thyroid cancer

Background and Purpose: Parenchymal impairment of salivary glands following high-dose radioiodine treatment is a well-known side effect in general cau sed by free radicals. Therefore, the radioprotective effect of the radical scavenger amifostine was evaluated prospectively in patients receiving high -dose radioiodine treatment. Patients and Methods: Parenchymal function was assessed by quantitative sal ivary gland scintigraphy performed in 50 patients with differentiated thyro id cancer prior to and 3 months after high-dose radioiodine treatment with either 3 GBq I-131 (n = 21) or 6 GBq I-131 (n = 29) in a double-blinded, pl acebo-controlled study. Twenty-five patients treated with 500 mg/m(2) amifo stine intravenously prior to high-dose radioiodine treatment were compared to 25 control patients receiving physiological saline solution. Xerostomia was graded according to WHO-criteria. Results: In 25 control patients high-dose radioiodine treatment significant ly (p < 0.001) reduced parenchymal function of parotid and submandibular gl ands by 40.2 +/- 14.1% and 39.9 +/- 15.3%, respectively. Nine out of these 25 patients developed Grade I and 2 Grade II xerostomia. In contrast, in 25 amifostine-treated patients there was no significant (p = 0.691) decrease in parenchymal function following high-dose radioiodine treatment, and xero stomia did not occur in any of them. Conclusion: Parenchymal damage of salivary glands induced by high-dose radi oiodine treatment can be significantly reduced by amifostine which may impr ove quality of life of patients with differentiated thyroid cancer.