Lack of efficacy of recombinant human thyrotropin versus thyroid hormone withdrawal for radioiodine therapy imaging in a patient with differentiated thyroid carcinoma lung metastases.

The treatment of lung metastases of thyroid cancer is nearly exclusively limited to the administration of iodine-131. For patients presented with micronodular lesions, the therapeutic response is often excellent, increasing life expectancy. Because of the necessity of multiple iodine-131 treatments in the course of this therapy, and subsequently, the lack of tolerance of hormonal withdrawal, the use of recombinant human thyrotropin (rhTSH) as a method of stimulation could represent an interesting alternative. However, as in the present case, the stimulation by rhTSH can be less effective than hormonal withdrawal, as shown in the posttherapy scan to detect metastatic lesions and thus could be detrimental to the treatment efficiency.