Role of recombinant human TSH in the management of large euthyroid multinodular goitre: a new therapeutic option? Pros and cons

Conventional 131 I treatment has been used in the last 20 years for large nodular goitres when patients present high surgical risk or simply refuse surgery. 131 I therapy causes a mean goitre volume reduction of about 40% after one year. However, the individual response is variable and for low radioiodine uptake and very large goitres, high 131 I activities are needed in order to have a adequate 131 I accumulation in the thyroid. rhTSH is approved for thyroid cancer management and has been tested off label in large goitres, in whom increases 131 I uptake, thus reducing the 131 I amount to be administered. The use of lower 131 I activities allows to reduce the radiation burden to body and the time of social life restriction. Moreover, depending on the radiation regulations of the different countries, the 131 I therapy could be carried out either as outpatients or in a shorter hospitalization period, implying a decrease of costs. The effects of rhTSH on goitre may be due not only to the 131 I uptake increase, but also to a more homogeneous distribution of 131 I in the gland, and to the thyroid cell activation that makes them more radiosensitive. Acute adverse effects are due to the surge of thyroid hormone in blood and to the goitre volume increase, that cause cardiac symptoms and tracheal compression, respectively. These effects are probably dose dependent and are negligible for rhTSH lower doses.