Hippokratia. 2012; 16(1):40-45

T. Aktoz, G. Durmus-Altun, U. Usta, N. Torun, A. Ergulen, I H. Atakan

Abstract

Background: Ablative radioiodine-131 (¹³¹I) therapy is used in the standart treatment procedure of thyroid carcinoma and procedures using ¹³¹I represent the majority of Nuclear Medicine therapeutic procedures. The principal route of ¹³¹I excretion after the administration of ¹³¹I is the urine. Amifostine is an organic thiophosphate ester prodrug and the kidney concentrations of the active metabolite WR-1065 are about 100 times higher than tumour concentrations. To our knowledge, there is no published data in literature presenting acute effect of radioiodine on renal tissue during high dose I-131 radioiodine treatment (RIT). Additionally, it is not known whether amifostine takes role in this process.
Materials and methods: In this study, 50 healthy female Wistar albino rats, weighing 200-250 g and averaging 16 weeks old were utilised. The rats were randomly divided into ten groups. 1- Sham group (n=5), 2- Amifostine group (n=5): rats pretreated with 1 cc amifostine (200 mg/kg) by intraperitoneal injection, 3- Radioactive iodine first day group (RI-1) (n=5): rats treated with 1 cc oral 185 MBq radioactive iodine-131 and sacrification performed after 1st day, 4- Amifostine + Radioactive iodine first day group (A+RI-1) (n=5): rats pretreated with amifostine (200 mg/kg) by intraperitoneal injection and rats treated with 5mCi radioactive iodine-131 and sacrification performed after 1st day. 5- Radioactive iodine third day group (RI-3) (n=5), 6- Amifostine + Radioactive iodine third day group (A+RI-3) (n=5), 7- Radioactive iodine fifth day group (RI-5) (n=5), 8- Amifostine + Radioactive iodine fifth day group (A+RI-5) (n=5), 9- Radioactive iodine seventh day group (RI-7) (n=5) and 10- Amifostine + Radioactive iodine seventh day group (A+RI-7) (n=5). The renal cast formation and tubular damage are evaluated by a pathologist in a blinded manner.
Results: Ablative radioiodine-131 therapy induced renal tubular damage was significantly higher in the radioactive iodine fifth day group (RI-5) when compared with the Sham group (p=0.01) and Amifostine group (p=0.01).
Conclusions: A marked ablative radioiodine-131 induced renal toxicity was seen at fifth day of the therapy after a single RIT application and the main histopathological change was tubular damage. Amifostine have protective effects against ablative radioiodine-131 therapy and this effect is significant at fifth day of the therapy.

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