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Surgery is the standard therapy for a large, severely compressive multinodular
goiter. In elderly patients or in cases of goiter recurrence after partial
thyroidectomy, surgery may be contraindicated. Then and also when tracheal
compression is not serious, radioiodine (131I) represents an effective
alternative to surgery, especially since in these cases, thyroid hormone
suppresion therapy is usually inefficient and badly tolerated by the patient.
An ablative dose of 131I ranging between 3.7 and 5.55 MBq (100-150 µCi) of 131I/g of thyroid tissue retained at 24 hr is used. It is notorious that whatever the method used (palpation, neck circumference, thyroid scintigraphy), the estimation of the volume of the thyroid gland remains imprecise. Echography is not applicable for the evaluation of the volume of large goiters, especially in the case of intrathoracic goiters. Nuclear magnetic resonance imaging can be used but may raise problems of accessibility or costs. All these considerations practically lead to the administration of 131I doses of 1,000 to 370,000 MBq (about 30 to 100 mCi). Doses of 131I of that magnitude imply hospitalization of the patient for reasons of radioprotection and for the risk of radiation thyroiditis which can result in a thyrotoxic crisis and/or a thyroid swelling aggravating any compressive symptoms of the trachea. The clinician has to carefully watch these potential complications which can usually be handled by corticosteroid therapy. Since these patients are expected to become hypothyroid sooner or later, they have to be started on substitution thyroid therapy shortly after 131I administration. According to the literature, the results of 131I treatment even of large goiters are encouraging and rarely accompanied by significant side effects. The administration of radioiodine in these patients undoubtly remains a reasonable therapeutic approach. |
