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.
Bohuslavizki
K H
KH
Clinic of Nuclear Medicine and Department of Pathology, Christian-Albrechts-University, Kiel, Germany.
Brenner
W
W
Klutmann
S
S
Hübner
R H
RH
Lassmann
S
S
Feyerabend
B
B
Lüttges
J
J
Tinnemeyer
S
S
Clausen
M
M
Henze
E
E
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