Single, very low dose (0.03 mg) of recombinant human thyrotropin (rhTSH) effectively increases radioiodine uptake in the I-131 treatment of large nontoxic multinodular goiter

Recombinant human thyrotropin (rhTSH)-aided radioiodine treatment for non-toxic multinodular goitre

BACKGROUND

Multinodular goitre is common in women. Treatments for non-toxic multinodular goitre include surgery, levothyroxine suppressive therapy, and radioiodine. Radioiodine therapy is the only non-surgical alternative for non-toxic multinodular goitre. However, a high amount of radioiodine is needed to enable the thyroid nodules to adequately take up the radioiodine, because the multinodular goitre takes up a low amount of iodine. Recombinant human thyrotropin (rhTSH) has been used to increase radioiodine uptake and reduce thyroid volume of the multinodular goitre. Whether the improved reduction of the goitre resulting from rhTSH-stimulated radioiodine therapy is beneficial to the person remains controversial.

OBJECTIVES

To assess the effects of recombinant human thyrotropin-aided radioiodine treatment for non-toxic multinodular goitre.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Scopus as well as ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 18 December 2020.

SELECTION CRITERIA

We included randomised controlled clinical trials (RCTs) comparing the effects of rhTSH-aided radioiodine treatment compared with radioiodine alone for non-toxic multinodular goitre, with at least 12 months of follow-up.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts for relevance. Screening for inclusion, data extraction, and risk of bias assessment were carried out by one review author and checked by a second. Our main outcomes were health-related quality of life (QoL), hypothyroidism, adverse events, thyroid volume, all-cause mortality, and costs. We used a random-effects model to perform meta-analyses, and calculated risk ratios (RRs) for dichotomous outcomes, and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We evaluated the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included six RCTs. A total of 197 participants were allocated to rhTSh-aided radioiodine therapy, and 124 participants were allocated to radioiodine. A single dose of radioiodine was administered 24 hours after the intramuscular injection of a single dose of rhTSH. The duration of follow-up ranged between 12 and 36 months. Low-certainty evidence from one study, with 85 participants, showed uncertain effects for QoL for either intervention. RhTSH-aided radioiodine increased hypothyroidism compared with radioiodine alone (64/197 participants (32.5%) in the rhTSH-aided radioiodine group versus 15/124 participants (12.1%) in the radioiodine alone group; RR 2.53, 95% CI 1.52 to 4.20; 6 studies, 321 participants; moderate-certainty evidence in favour of radioiodine alone). A total of 118/197 participants (59.9%) in the rhTSH-aided radioiodine group compared with 60/124 participants (48.4%) in the radioiodine alone group experienced adverse events (random-effects RR 1.24, 95% CI 0.94 to 1.63; 6 studies, 321 participants; fixed-effect RR 1.23, 95% CI 1.02 to 1.49 in favour of radioiodine only; low-certainty evidence). RhTSH-aided radioiodine reduced thyroid volume with a MD of 11.9% (95% CI 4.4 to 19.4; 6 studies, 268 participants; moderate-certainty evidence). One study with 28 participants reported one death in the radioiodine alone group (very-low certainty evidence). No study reported on costs.

AUTHORS' CONCLUSIONS

RhTSH-aided radioiodine treatment for non-toxic multinodular goitre, compared to radioiodine alone, probably increased the risk of hypothyroidism but probably led to a greater reduction in thyroid volume. Data on QoL and costs were sparse or missing.

Recombinant Human Thyrotropin-Stimulated Radioiodine Therapy in Patients with Multinodular Goiters: A Meta-Analysis of Randomized Controlled Trials

A potential reduction of goiter volume (GV) of recombinant human thyrotropin (rhTSH) on multinodular goiters (MNG) was previously reported but controversial. Hence we conducted a meta-analysis to estimate the effect of rhTSH-stimulated radioiodine therapy in patients with MNG. PubMed, Cochrane, CNKI, VIP, and Wanfang databases were searched. Mean difference (MD) and odds ratios with 95% confidence intervals (95% CI) were derived by using an inverse variance random-effects model and fixed-effects model, respectively. Six studies (n=237) were involved in the analysis. For 12 months follow up, high dose (>0.1 mg) of rhTSH significantly reduced GV (MD=17.61; 95% CI=12.17 to 23.04; p<0.00001) compared with placebo. No effective pooled results of low dose of rhTSH (<0.1 mg) were applicable for only one study included. For 6 months follow up, the source of heterogeneity was determined by subgroup and sensitivity analysis. High dose group showed vast improvement in GV reduction (MD=16.62; 95% CI=1.34 to 31.90; p=0.03). The reduction of low dose group compared with placebo was inferior to high dose group. No available data were obtained to assess the influence of rhTSH after 36 months follow up for the only included study. Hypothyroidism incidence was higher for rhTSH group. No publication bias was seen. High dose of rhTSH treatment-stimulated radioactive ¹³¹I therapy after 6 months and 12 months follow up had a better effect in reducing GV, but with higher incidence of hypothyroidism. Owing to the limited methodological quality, more clinical researches are warranted in the future.

Fixed 30 mCi 131I-iodine therapy without recombinant human thyroid-stimulating hormone stimulation as an attractive therapeutic alternative in nontoxic nodular goiter

OBJECTIVE

To analyze outcomes of patients with compressive nontoxic multinodular goiter after 131I-iodine 30 mCi treatment without previous use of recombinant human thyroid-stimulating hormone or methimazole.

METHODS

We evaluated fixed-dose radioiodine therapy outcomes in patients with nontoxic multinodular goiter who did not accept thyroidectomy as a therapeutic option. Laboratory thyroid function and thyroid volume estimated by ultrasound were assessed before and one year after radioiodine therapy.

RESULTS

Twenty euthyroid female patients received 30 mCi of 131I-iodine without recombinant human thyroid-stimulating hormone or methimazole pretreatment. Median thyroid volume and Tc-99m sodium pertechnetate thyroid uptake before radioiodine therapy were 68.05 cm (31.3-295.3) and 0.5% (0.1%-1.2%), respectively. One year after radioiodine therapy, thyroid volume decreased to 55.4 cm (19.8-149.9), and merely 4 patients (20%) developed hypothyroidism. Thyroid volume decreased significantly after radioiodine therapy, presenting a variation of -21.1 cm (-161.3 to -0.8) and -30.61% (-73.88 to -1.02), both with P < 0.0001. Thyroid volume variation was positively correlated with thyroid uptake in Spearman's correlation (r = 0.4730; P = 0.0352). The group satisfied with radioiodine therapy (85%, n = 17) showed a significant reduction in thyroid volume, -25.8 cm (-161.3 to -6.2) and -36.74% (-73.88 to -9.95). The dissatisfied group (15%, n = 3) showed -1.0 cm (-2.0 to -0.8) and -1.67% (-3.38 to -1.02) in thyroid volume, P = 0.0081. Patients that complained about dysphagia presented a lower percentage of thyroid volume decrease after radioiodine therapy, -21.97% (-70.12 to -1.02, P = 0.0430).

CONCLUSIONS

A substantial reduction in thyroid volume associated with a low incidence of hypothyroidism and a high satisfaction rate support the use of conventional radioiodine therapy with a fixed dose of 30 mCi. This therapy is an attractive and cheaper therapeutic alternative in selected patients with nontoxic multinodular goiter.

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

PURPOSE

It is possible to raise the rate of the uptake of ¹³¹I in the thyroid gland (RAIU) by increasing the endogenous TSH level through appropriate use of methimazole (MMI) prior to ¹³¹I therapy. The purpose of this paper is to assess the impact of pre treatment with MMI on the efficacy of ¹³¹I therapy in non-toxic multinodular goitre (NMG).

METHODS

Thirty-one patients with NMG received ¹³¹I treatment in order to reduce the volume of the thyroid (TVR). Those in group 1 (n = 16) were administered 10 mg of methimazole for 6 weeks. Four days after its discontinuation, they received ¹³¹I. Patients in group 2 (n = 15) were given a placebo instead of MMI. The therapeutic activity of ¹³¹I was constant (800 MBq) and was repeated every 6 months. Treatment was discontinued when TVR reached <40 ml.

RESULTS

In group 1, RAIU increased approximately twofold. Ten patients from group 2 and four patients from group 1 received further doses of ¹³¹I. The median of time until TVR decreased below 40 ml was 9 months [6-12 months] and 18 months [14-22 months] in group 2. At 2 years after the ¹³¹I therapy, the occurrence of hypothyroidism did not differ significantly (36% in group 1 and 33% in group2, p = 0.074).

CONCLUSIONS

Radioiodine treatment of NMG preceded with appropriate application of MMI is efficient thanks to increased RAIU, shorter period of treatment, and lower frequency of ¹³¹I administration, without an increase in the incidence of post-treatment hypothyroidism.

Recombinant human thyrotropin stimulated 131I treatment for multinodular goiter

The aim of the study was to investigate the effects of rhTSH stimulation before ¹³¹I treatment in patients with MNG.

METHODS

Sources included the Cochrane Library, MEDLINE, EMBASE, and SCOPUS database (all until January 2016). Randomized controlled trials (RCTs) that assessed the efficacy of rhTSH-stimulated ¹³¹I treatment compared to placebo or ¹³¹I treatment alone were collected. Two authors performed the data extraction independently.

RESULTS

Six RCTs involving 294 patients with MNG were included in this review. Altogether 168 patients were randomized to rhTSH-stimulated ¹³¹I therapy, and 126 to either placebo and ¹³¹I or ¹³¹I alone. rhTSH-stimulated ¹³¹I vs placebo and ¹³¹I or ¹³¹I alone for MNG showed no statistically significant difference in quality of life and all-cause mortality. rhTSH- (at a dose of 0.03 mg and above) stimulated ¹³¹I treatment for MNG showed significant benefits in thyroid volume reduction. ¹³¹I treatment with rhTSH stimulation at high doses (0.03 mg, 0.1 mg, 0.3 mg and 0.45 mg) for MNG caused significantly higher adverse effects and hypothyroidism.

CONCLUSIONS

The overall results indicated that using rhTSH at high doses of 0.03-0.45 mg before ¹³¹I therapy resulted in a greater TVR than ¹³¹I therapy alone for patients with non-toxic MNG. However, an increased incidence of adverse effects and hypothyroidism was observed in patients receiving high-dose of rhTSH pretreatment than in patients who received low-dose rhTSH pretreatment. Therefore, a dose of 0.03 mg rhTSH pretreatment before ¹³¹I therapy may be more potent than ¹³¹I alone in treating patients with non-toxic MNG who either had a contraindication for or declined surgery.