Endocrine Abstracts

Recombinant human TSH (rhTSH) has recently been used as an adjuvant to the treatment of non-toxic multinodular goitre (MNG) by means of ¹³¹I. The aim of our study was to evaluate the efficacy of 0.2 mg rhTSH or placebo administered im on 2 consecutive days before a fixed therapeutic dose of 14 mCi of ¹³¹I. Thirteen elderly patients (71±7 years) with large non-toxic MNG (group 1) were treated with rhTSH plus ¹³¹I. While a control group of 8 patients, matched for age and non-toxic MNG volume, was treated with placebo plus ¹³¹I (group 2). In all patients, surgery was either contraindicated or refused. Examinations were performed before and 3–180 days after the first rhTSH or placebo administration and then 6–24 months after therapy. Before and after ¹³¹I therapy thyroid volume (TV) was evaluated by ultrasound. The number and severity of side-effects was similar in both groups of subjects. On final examination, the number of patients symptomatic for goitre was significantly lower in group 1 than in group 2 (P=0.03). In group 1, TSH levels peaked to 40.3±9.5 mU/l on day 3 from the baseline value of 0.5±0.1 mU/l (P<0.001). While a marked increase in f-T3, f-T4 and thyroglobulin (P<0.001) was noted in both groups during the first 2 weeks of treatment, peak values were much higher in group 1 than in group 2. At the end of the study the percentage of patients who did not need therapy to control TSH secretion was higher (P=0.06) in group 1 (83%) than in group 2 (38%). In group 1, TV was reduced from 78±11 ml to 49±13 ml (P=0.004) and from 90±25 ml to 67±20 ml in group 2. Median TV reduction from baseline values was 48% and 28% in groups 1 and 2, respectively. In conclusion, this long-term controlled study demonstrates that 0.2 mg administered on 2 consecutive days increases the efficacy of low ¹³¹I (14mCi) doses in the treatment of non-toxic MNG in elderly subjects. ß-blockers generally prevent side-effects due to short-term but marked thyrotoxicosis, which is enhanced by rhTSH administration. The most important effect of rhTSH administration before ¹³¹I is to reduce TV.