Mehrossadat Alavi - Medical Imaging Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
Fatemeh Zal - Biochemistry Department, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
Fahimeh Zamani - Biochemistry Department, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
Mehdi Kazemi - Nuclear Medicine Department, Shiraz University of Medical Sciences, Shiraz, Iran
Mozhgan Rasti - Biochemistry Department, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran

Background: This study aimed to assess several biochemical and oxidative stress parameters before and after radioiodine therapy in patients with well-differentiated thyroid cancer who consumed a low iodine diet and withdrawal of levothyroxine after total thyroidectomy.Methods: We enrolled ۴۰ candidates for radioiodine therapy. Blood sampling was performed prior to as well as ۷۲ h after consumption of ۱۲۵-۲۰۰ mCi of ۱۳۱I. Total protein, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and creatinine were measured. Oxidative stress parameters that included malondialdehyde and protein carbonyl levels were also assessed.Results: There were significantly decreased total protein, creatinine, aspartate aminotransferase, and alanine aminotransferase levels (P<۰.۰۰۱) after treatment. However, malondialdehyde levels increased significantly (P<۰.۰۵) over the studied time.Conclusion: We found that radioactive iodine absorption in peripheral tissues due to a low-iodine diet and levothyroxine withdrawal could relieve iodine deficiency in the liver and kidneys which resulted in reduced total protein, aspartate aminotransferase, alanine aminotransferase, and creatinine levels. However, it induced oxidative stress by increasing malondialdehyde levels in the blood.