Thyroid carcinoma is the most prevalent endocrine malignancy and accounts for 1% of all human cancers. More than 90% of TCs are well-differentiated. (1,2) which is defined as a carcinoma derived from the follicular epithelium and retaining basic biological characteristics of healthy thyroid tissue, including expression of the sodium iodide symporter (NIS), the key cellular feature for specific iodine uptake. It represents 70% to 90% of Thyroid Cancer and includes papillary and follicular carcinoma with all its histological variants. DTC is an uncommon disease clinically but worldwide, its incidence shows a noticeable increase (3). In most cases, prognosis is favorable and treatment consisting of primary surgery and ablative radioiodine administration achieves a 10-y survival rate of 80%–90%
(4). Radioiodine is used in the management of differentiated thyroid carcinoma based on the premise that normal, as well as malignant thyroid tissues have selective uptake of radioactive iodine. It is used in various situations; diagnostic or therapeutic including ablative treatment of residual normal thyroid tissue and treatment of distant metastases (4-7). However when thyroid cancer cells lose their basic biological characteristics of taking up and concentrate iodine, this is called Cell De-differentiation, which is genetically based complex process that produces multiple molecular changes occurring in about 5% of cases and usually accompanied by more aggressive growth, metastatic spread, and inability to trap iodide, making the tumor resistant to radioiodine ablation and poorly responsive to conventional therapy (8).