TG and thyroid gland carcinoma: The Centres for Medicare and Medicaid Services (USA) began coverage of FDG-PET procedure in October 2003, for restaging of recurrent or residual thyroid cancer of follicular cell origin that has previously been treated by thyroidectomy and radioiodine ablation in patients with serum Tg levels of 10ng/ml or greater and negative I-131 WBS.