THERAPY OF ENDOCRINE DISEASE: Recombinant human TSH and radioactive iodine therapy in the management of benign multinodular goiter

Abstract

Multinodular goiter (MNG) is a very common thyroid disorder determined by diverse goitrogenic factors, the most important one being iodine deficiency. The clinical presentation of a patient with MNG varies from a completely asymptomatic goiter to a life-threatening disease due to upper airway compression. Patients can develop underlying subclinical or overt hyperthyroidism due to autonomously hyperfunctioning nodules. In the absence of clinical, ultrasonographic, or cytological findings suggestive of malignancy, the best therapeutic approach for a patient with MNG will depend on the size and location of the goiter, the presence and severity of compressive symptoms, and the presence or absence of thyrotoxicosis. There is still no consensus regarding the treatment of atoxic MNGs. Hence, its optimal management remains controversial; possible therapies include levothyroxine (LT 4 ), surgery, and radioactive iodine ( 131 I). Suppressive treatment with LT 4 is discouraged due to the development of sub-clinical or overt hyperthyroidism and to its low efficacy when compared with surgery or 131 I. Total thyroidectomy is effective; however, it is associated with the risk of surgical complications and is often refused by the patient. 131 I therapy is an alternative to thyroid surgery to reduce the size of benign MNGs. Based on the ability of recombinant human TSH (rhTSH) to more than double thyroid 131 I uptake, this compound has been evaluated as an adjuvant to 131 I in the treatment of MNG. Very small doses of rhTSH have been used in patients with MNG and few safety concerns have been observed, but the ideal dose, both effective and safe, is yet to be defined.

Enhancing the efficacy of 131I therapy in non-toxic multinodular goitre with appropriate use of methimazole: an analysis of randomized controlled study

“…Admittedly, this result may be affected by an estimation error due to the relatively small patient sample (31 persons). Nevertheless, other authors reached similar conclusions, even though in their studies, the rise in RAIU was achieved through administration of rhTSH, instead of MMI [16,17].…”

Which Is the Ideal Treatment for Benign Diffuse and Multinodular Non-Toxic Goiters?

“…Most studies analyzing rhTSH in this setting have used fixed doses of radioiodine ranging from ~14 to ~42 mCi ( 37 ) and treatment with one or two rhTSH doses ranging from 0.1 to 0.3 mg administered 24 h prior to the radioiodine. However, the dose with ideal efficacy and safety is yet to be defined ( 47 ).…”

The Presence of Anti-TPO Antibodies Increase the Likelihood of Post-I131 Hypothyroidism

“…RAI can be used to cure the hyperthyroid state, but can also lead to a decrease in thyroid size [7]. In patients with MNG, radioactive iodine therapy can cause a decrease in thyroid size by up to 34 % in 12 months and 55 % after 24 months [8].…”