Effect of 30 mCi radioiodine on multinodular goiter previously treated with recombinant human thyroid-stimulating hormone

Abstract

Recombinant human thyroid-stimulating hormone (rhTSH) enhances 131 I uptake, permitting a decrease in radiation for the treatment of multinodular goiter (MNG). Our objective was to evaluate the safety and efficacy of a single 0.1-mg dose of rhTSH, followed by 30 mCi 131 I, in patients with MNG. Seventeen patients (15 females, 59.0 ± 13.1 years), who had never been submitted to 131 I therapy, received a single 0.1-mg injection of rhTSH followed by 30 mCi 131 I on the next day. Mean basal thyroid volume measured by computed tomography was 106.1 ± 64.4 mL. 131 I 24-h uptake, TSH, free-T4, T3, thyroglobulin, anti-thyroid antibodies, and thyroid volume were evaluated at regular intervals of 12 months. Mean 131 I 24-h uptake increased from 18.1 ± 9.7 to 49.6 ± 13.4% (P < 0.001), a median 2.6-fold increase (1.2 to 9.2). Peak hormonal levels were 10.86 ± 5.44 mU/L for TSH (a median 15.5-fold increase), 1.80 ± 0.48 ng/dL for free-T4, 204.61 ± 58.37 ng/dL for T3, and a median of 557.0 ng/mL for thyroglobulin. The adverse effects observed were hyperthyroidism (17.6%), painful thyroiditis (29.4%) and hypothyroidism (52.9%). Thyroid volume was reduced by 34.3 ± 14.3% after 6 months (P < 0.001) and by 46.0 ± 14.6% after 1 year (P < 0.001). Treatment of MNG with a single 0.1-mg dose of rhTSH, followed by a fixed amount of radioactivity of 131 I, leads to an efficacious decrease in thyroid volume for the majority of the patients, with a moderate incidence of non-serious and readily treatable adverse effects.

Optimizing 131I Uptake After rhTSH Stimulation in Patients with Nontoxic Multinodular Goiter: Evidence from a Prospective, Randomized, Double-Blind Study

“…This observation is in line with previous studies (9,10,12). Consequently, patients with a low RAIU benefit the most from rhTSH stimulation.…”

“…Because the effect of rhTSH is highly dependent on the stable iodine load (21) and, especially, the baseline RAIU-but also to some extent on rhTSH dose-comparing this result with previous studies of NMG patients is difficult. In previous studies (9)(10)(11)(12)(13)22), an increase in 24-h RAIU between 68% and 335% was found using rhTSH doses from 0.01 to 0.45 mg. This considerable variation can mainly be attributed to differences in baseline RAIU (12%233%) and to the dose of rhTSH used.…”

“…Recombinant human thyroid-stimulating hormone (rhTSH) increases the thyroid RAIU by approximately 100% in both healthy individuals (7,8) and goiter patients (9)(10)(11)(12)(13). In 3 randomized controlled trials (13)(14)(15), rhTSH has been documented to enhance the goiter volume reduction by 35%256% when standard 131 I activities are used.…”

Time to reconsider nonsurgical therapy of benign non-toxic multinodular goitre: focus on recombinant human TSH augmented radioiodine therapy

“…In addition, measurements of RAIU are extremely prone to variation in the method used. Despite these shortcomings, studies in MNG patients (19,20,40,(43)(44)(45)(46) and healthy individuals (41,42,47) document an approximately twofold increase in RAIU, largely independent of rhTSH dose. In support of this observation, a small comparative trial found that 0.03 mg was not superior to 0.01 mg (40) and another comparative trial observed that 0.3 mg was not superior to 0.1 mg (45).…”

“…The remaining non-controlled studies (Table 2) have demonstrated considerable GVR between 35 and 53% (20, 43, 44, 46, 52, 53), 6-12 months after rhTSHaugmented 131 I therapy. Although lacking a control group, the results are promising since some of the latter studies (43,46) were carried out in patients with relatively low baseline RAIU, thus demonstrating the feasibility of 131-I therapy in such patients when employing rhTSH. One study, in 18 MNG patients with a baseline RAIU of 12%, documented a mean GVR of 39% after 6 months and 53% after 2 years (43, 54).…”