In France, 3,700 new cases of thyroid cancer are diagnosed each year. Differentiated thyroid carcinoma represents more than 90% of all thyroid cancers; and has a 10-year survival of 90-95% of patients. This favorable prognosis is the result of an effective primary therapy, which consists of a total thyroidectomy that is followed by radio-iodine ablation with 3,7GBq (100mCi) in case of significant risk of persistent disease. Few centers investigated the possibility to administer lower doses of 131I (1GBq, 30 mCi), in order to limit the potential long-term adverse complications for patients and to respond to radioprotection rules for family members and medical staff.

Radio-iodine ablation requires TSH stimulation, which was historically achieved by thyroid hormone withdrawal for 3 to 5 weeks. During this period, patients suffered from symptoms of hypothyroidism. The recombinant human TSH (rhTSH, Thyrogen®, Genzyme Therapeutics, Cambridge, USA) was approved in Europe in 2005 as an alternative stimulation procedure to withdrawal during ablation. It allows patients to remain euthyroid on thyroid hormone therapy (that needs not to be withdrawn). However, this a costly drug (800 € per patient), whose economic efficiency needs to be checked.