Radioprotection of salivary glands by amifostine in high-dose radioiodine therapy.
Salivary gland impairment after high-dose radioiodine treatment is well recognized. Because differentiated thyroid cancer has a good prognosis, reduction of long-term side effects is important. This study investigated the radioprotective effects of amifostine in animals and humans receiving high-dose radioiodine therapy.


METHODS
Quantitative salivary gland scintigraphy was performed in five rabbits before and up to 3 mo after high-dose radioiodine therapy applying 1 GBq 131I. Three animals received 200 mg/kg amifostine before high-dose radioiodine therapy, and two served as controls. All animals were examined histopathologically. Quantitative salivary gland scintigraphy also was performed in 17 patients with differentiated thyroid cancer before and 3 mo after high-dose radioiodine therapy with 6 GBq 131I. Eight patients were treated with 500 mg/m2 amifostine before high-dose radioiodine therapy, and nine served as controls.


RESULTS
In two control rabbits, high-dose radioiodine therapy significantly reduced parenchymal function by 63% and 46% in parotid and submandibular glands, respectively. In contrast, there was no significant decrease in parenchymal function in amifostine-treated animals. Histopathologically, lipomatosis was observed in control animals but was negligible in amifostine-treated animals. Similar findings were observed in differentiated thyroid cancer patients. In nine control patients, high-dose radioiodine therapy significantly (p < 0.01) reduced parenchymal function by 37% and 31% in parotid and submandibular glands, respectively. Three patients exhibited Grade I (World Health Organization) xerostomia. In contrast, there was no significant decrease in parenchymal function in amifostine-treated patients and no incidence of xerostomia.


CONCLUSIONS
Parenchymal damage in salivary glands induced by high-dose radioiodine therapy can be reduced significantly by amifostine. This may increase the quality of life of patients with differentiated thyroid cancer.
Clinic of Nuclear Medicine and Department of Pathology, Christian-Albrechts-University, Kiel, Germany.
K H
KH
Bohuslavizki
W
W
Brenner
S
S
Klutmann
R H
RH
Hübner
S
S
Lassmann
B
B
Feyerabend
J
J
Lüttges
S
S
Tinnemeyer
M
M
Clausen
E
E
Henze
D018263:Adenocarcinoma, Follicular / Q000532:radiotherapy; D000328:Adult; D000368:Aged; D004999:Amifostine / Q000627:therapeutic use*; D000818:Animals; D002291:Carcinoma, Papillary / Q000532:radiotherapy; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011877:Radionuclide Imaging; D011879:Radiotherapy Dosage; D012469:Salivary Glands / Q000000981:diagnostic imaging / Q000528:radiation effects*; D013670:Sodium Pertechnetate Tc 99m; D013964:Thyroid Neoplasms / Q000532:radiotherapy*
D007457:Iodine Radioisotopes; D011837:Radiation-Protective Agents; D013670:Sodium Pertechnetate Tc 99m; D004999:Amifostine