Salivary gland protection by amifostine in high-dose radioiodine therapy of differentiated thyroid cancer

Background: Salivary gland impairment following high-dose radioiodine treat ment is a well-recognized side effect, in general caused by free radicals. Therefore, it seemed promising to evaluate the radioprotective effect of th e radical scavenger amifostine in patients receiving high-dose radioiodine therapy. Patients and Method: Quantitative salivary gland scintigraphy using 100 to 120 MBq Tc-99m-pertechnetate was performed in 17 patients with differentiat ed thyroid cancer prior to and 3 months after radioiodine treatment with 6 GBq I-131. Eight patients were treated with 500 mg/m(2) amifostine prior to high-dose radioiodine treatment and compared retrospectively with 9 contro l patients. Xerostomia was graded according to WHO criteria. Results: In 9 control patients high-dose radioiodine treatment significantl y (p < 0.01) reduced Tc-99m-pertechnetate uptake by 35.4 +/- 22.0% and 31.7 +/- 21.1% in parotid and submandibular glands, respectively. Of these 9 pa tients, 3 exhibited xerostomia Grade I (WHO). In contrast, in 8 amifostine- treated patients, there was no significant (p = 0.878) decrease in parenchy mal function following high-dose radioiodine treatment, and xerostomia did not occur in any of them. Conclusion: Parenchymal damage in salivary glands induced by high-dose radi oiodine treatment can be reduced significantly by amifostine. This may help to increase patients' quality of life in differentiated thyroid cancer.