Analysis of ¹³¹I therapy and correlation factors of Graves' disease patients: a 4-year retrospective study

Effect of Lugol's solution on 131I therapy efficacy in Graves' disease

PURPOSE

Lugol's solution could control thyroid function and suppress ¹³¹I uptake in hyperthyroidism. This study aimed to investigate the appropriate time to withdraw Lugol's solution before ¹³¹I therapy (RIT) in Graves' disease (GD) patients, and how this should influence ¹³¹I uptake and RIT outcome.

METHODS

Two groups (125 cases and 1805 cases) of GD patients received RIT, who were pre-treated with and without Lugol's solution (RI-CI group and RI group). The RI-CI group was further divided into the following sub-groups depending on the duration span between Lugol's solution withdrawal and RIT: sub-group A, 4-7 d (n = 49); sub-group B, 8-14 d (n = 41); and sub-group C, 15-30 d (n = 35). The highest radioactive iodine uptake rate (RAIU_max), effective half-life (T_eff), TRAb, and free triiodothyronine (FT₃) and free thyroxine (FT₄) levels were compared, and therapeutic outcome was evaluated.

RESULTS

There were no significant differences in RAIU_max, TRAb, and T_eff among the four sub-groups (P > 0.05). Both FT₃ and FT₄ levels in sub-groups A and B were lower than those in group RI and sub-group C (P < 0.05). The outcome of non-hyperthyroidism (euthyroidism + hypothyroidism) in groups RI-CI and RI was significantly different at post-RIT month 1 and 3 (P < 0.05). However, intergroup differences at 6 and 12 months were not significant (P > 0.05).

CONCLUSIONS

Withdrawal of Lugol's solution 4-7 or 8-14 d before RIT does not influence ¹³¹I uptake and RIT efficacy in GD. Moreover, in order to avoid a rapid increase in thyroid hormone levels at the same time, Lugol's solution should be withdrawn 4-7 d before RIT.

Machine learning identifies baseline clinical features that predict early hypothyroidism in patients with Graves' disease after radioiodine therapy

Background and objective

Radioiodine therapy (RAI) is one of the most common treatment solutions for Graves' disease (GD). However, many patients will develop hypothyroidism as early as 6 months after RAI. This study aimed to implement machine learning (ML) algorithms for the early prediction of post-RAI hypothyroidism.

Methods

Four hundred and seventy-one GD patients who underwent RAI between January 2016 and June 2019 were retrospectively recruited and randomly split into the training set (310 patients) and the validation set (161 patients). These patients were followed for 6 months after RAI. A set of 138 clinical and lab test features from the electronic medical record (EMR) were extracted, and multiple ML algorithms were conducted to identify the features associated with the occurrence of hypothyroidism 6 months after RAI.

Results

An integrated multivariate model containing patients' age, thyroid mass, 24-h radioactive iodine uptake, serum concentrations of aspartate aminotransferase, thyrotropin-receptor antibodies, thyroid microsomal antibodies, and blood neutrophil count demonstrated an area under the receiver operating curve (AUROC) of 0.72 (95% CI: 0.61-0.85), an F1 score of 0.74, and an MCC score of 0.63 in the training set. The model also performed well in the validation set with an AUROC of 0.74 (95% CI: 0.65-0.83), an F1 score of 0.74, and a MCC of 0.63. A user-friendly nomogram was then established to facilitate the clinical utility.

Conclusion

The developed multivariate model based on EMR data could be a valuable tool for predicting post-RAI hypothyroidism, allowing them to be treated differently before the therapy. Further study is needed to validate the developed prognostic model at independent sites.

Predictive factors for early hypothyroidism following the radioactive iodine therapy in Graves' disease patients

BACKGROUND

Radioactive iodine (RAI) therapy is an important treatment option for Graves' disease (GD), the main side effect of RAI treatment is hypothyroidism, and the factors resulting in hypothyroidism are still controversial. The purpose of this retrospective study was to clarify the possible risk factors of early hypothyroidism after RAI therapy in Graves' disease.

METHODS

We reviewed 312 GD patients treated with RAI between January 2017 to December 2018, collected the potential risk factors, and analyzed the relationship between these variables and early hypothyroidism.

RESULTS

After 6 months' follow-up, 218 (69.87%) patients were evaluated as early hypothyroid. Male gender, shorter duration of disease, smaller thyroid weight, lower 2-h radioactive iodine uptake (RAIU), 6-h RAIU, 24-h RAIU and 6/24-h uptake ratio, lower administered dosages were significantly associated with early hypothyroidism. Logistics regression analysis showed that male gender, smaller thyroid weight and lower 6-h RAIU were associated with early hypothyroidism. Multi-factors combined ROC curve analysis suggested that the predictive power of male gender, smaller thyroid weight and lower 6-h RAIU for early hypothyroidism was 0.711.

CONCLUSIONS

Our results show that RAI is an effective therapy for GD and most of the cured patients became to hypothyroid within 6 months. Male gender, smaller thyroid weight and lower 6-h RAIU are the main risk factors for early hypothyroidism.

Dose optimization of lithium to increase the uptake and retention of I-131 in rat thyroid

The present study was undertaken to optimize the dose of lithium, with an aim to increase the retention of I-131 in the thyroid follicles while maintaining the euthyroid state. 24 female Wistar rats weighing 110 ± 20 g were segregated into four groups. Animals in group I were fed standard laboratory feed and water throughout the period of experimentation. Animals in group II, III and IV were additionally fed with lithium in the form of lithium carbonate orally, at a dose of 10 mg/kg body weight, 20 mg/kg body weight, 30 mg/kg body weight respectively. The dose of lithium was started 1 week prior to radioiodine administration and continued thereafter for another 8 days. After 7 days of lithium treatment, 0.48 MBq of carrier-free I-131 was injected intraperitoneally into each rat, of the four groups. I-131 thyroidal uptake and biokinetics, as well as serum TSH, T3, T4 levels were estimated in all the treatment groups. A significant increase in the thyroid and whole body counts was observed after 4 and 24 h of I-131 aministration in lithium treated rats, compared to control animals. An increase in thyroidal effective t_1/2 and serum TSH levels, along with decrease in the levels of serum T3 and T4 was observed with a dose of 20 mg/kg or higher. In Conclusion, a Lithium dose of 10 mg/kg body weight in rats could increase the uptake of I-131 in the thyroid, without disturbing the control circulating levels of thyroid hormones.

Gender impact on the correlations between Graves' hyperthyroidism and hyperuricemia in Chinese

OBJECTIVE

An increased level of serum uric acid (SUA) can be observed in patients with hypothyroidism. Nonetheless, data on the relationship between hyperuricemia and hyperthyroidism was still controversial. Thus, we aimed to analyze the association between Graves' hyperthyroidism and hyperuricemia in Chinese men and women.

METHODS

We recruited 103 male and 254 female patients with Graves' hyperthyroidism, as well as the same number of control subjects. Anthropometric measurements and fasting blood tests were collected and analyzed statistically by binary logistic regressions to determine the risk of developing hyperuricemia in hyperthyroidism.

RESULTS

SUA levels in males were significantly higher than that in females in both patients and controls. SUA levels were also significantly increased in hyperthyroid patients compared to in controls in both genders. The incidence of hyperuricemia rose significantly in subjects with hyperthyroidism with a higher prevalence in males than in females. SUA was negatively correlated with age and fasting glucose in male hyperthyroid patients, while it was positively correlated with body height, body weight, free triiodothyronine, and free thyroxine in female patients. Hyperthyroidism was a risk factor for hyperuricemia with an odd ratio of 4.536 for men and 2.730 for women.

CONCLUSIONS

For hyperuricemia, hyperthyroidism was an important risk factor that should not be neglected, especially for men.

99mTc-pertechnetate thyroid scintigraphy predicts clinical outcomes in personalized radioiodine treatment for Graves' disease

OBJECTIVE

The aim of this study was, first, to ascertain the efficacy of radioiodine therapy (RIT) for Graves' disease (GD) based on a calculated-dose regime and, second, to determine the value of ^99mTc-pertechnetate thyroid scintigraphy in predicting the clinical outcomes of RIT.

METHODS

One hundred and thirty 9consecutive GD patients who underwent RIT using a calculated-dose method in our hospital from January 2015 to September 2015 were retrospectively evaluated. Radioiodine dose was calculated based on the Marinelli's formula. ^99mTc-pertechnetate uptake, age, gender, thyroid mass, duration of the disease, previous antithyroid drugs treatment, serum levels of TSH, FT3 and FT4, a positive rate of TPOAb and Anti-TRAb, radioiodine dose and follow-up were evaluated as potential interference factors for RIT success.

RESULTS

One hundred and 8(77.7%) GD patients including 71 (51.1%) euthyroid and 37 (26.6%) hypothyroid were successful, but 31 (22.3%) remained hyperthyroid (treatment failure). Significant differences were found between the treatment success group and the failure group in ^99mTc-pertechnetate uptake (p<0.0001), the duration of disease (P=.0140) and positive rate of Anti-TRAb (P=.0103). ^99mTc-pertechnetate uptake is an independent risk factor for predicting treatment failure (P=.0394). Using a cut-off value of 18.4%, ^99mTc-pertechnetate uptake could predict treatment failure with a sensitivity of 84.3%, and a specificity of 80.6%.

CONCLUSION

Our study has shown that a calculated radioiodine dose is effective in treating GD patients with a consequent low rate of hypothyroid. A ^99mTc-pertechnetate uptake above 18.4% is a significant predictor of treatment failure and these patients should receive a higher radioiodine dose in this scenario.

The effect of short-term treatment with lithium carbonate on the outcome of radioiodine therapy in patients with long-lasting Graves' hyperthyroidism

OBJECTIVE

The outcome of radioiodine therapy (RIT) in Graves' hyperthyroidism (GH) mainly depends on radioiodine (¹³¹I) uptake and the effective half-life of ¹³¹I in the gland. Studies have shown that lithium carbonate (LiCO₃) enhances the ¹³¹I half-life and increases the applied thyroid radiation dose without affecting the thyroid ¹³¹I uptake. We investigated the effect of short-term treatment with LiCO₃ on the outcome of RIT in patients with long-lasting GH, its influence on the thyroid hormones levels 7 days after RIT, and possible side effects.

METHODS

Study prospectively included 30 patients treated with LiCO₃ and ¹³¹I (RI-Li group) and 30 patients only with ¹³¹I (RI group). Treatment with LiCO₃ (900 mg/day) started 1 day before RIT and continued 6 days after. Anti-thyroid drugs withdrawal was 7 days before RIT. Patients were followed up for 12 months. We defined a success of RIT as euthyroidism or hypothyroidism, and a failure as persistent hyperthyroidism.

RESULTS

In RI-Li group, a serum level of Li was 0.571 ± 0.156 mmol/l before RIT. Serum levels of TT₄ and FT₄ increased while TSH decreased only in RI group 7 days after RIT. No toxic effects were noticed during LiCO₃ treatment. After 12 months, a success of RIT was 73.3% in RI and 90.0% in RI-Li group (P < 0.01). Hypothyroidism was achieved faster in RI-Li (1st month) than in RI group (3rd month). Euthyroidism slowly decreased in RI-Li group, and not all patients became hypothyroid for 12 months. In contrast, euthyroidism rapidly declined in RI group, and all cured patients became hypothyroid after 6 months.

CONCLUSION

The short-term treatment with LiCO₃ as an adjunct to ¹³¹I improves efficacy of RIT in patients with long-lasting GH. A success of RIT achieves faster in lithium-treated than in RI group. Treatment with LiCO₃ for 7 days prevents transient worsening of hyperthyroidism after RIT. Short-term use of LiCO₃ shows no toxic side effects.

An improved method for the establishment of a model of Graves' disease in BALB/c mice

The present study aimed to develop a stable Graves' disease (GD) model in BALB/c mice by immunization and electroporation (EP). A total of 90 mice were divided into experimental (n=50), control (n=20) and blank (n=20) groups. The recombinant plasmid pcDNA3.1/thyroid-stimulating hormone (TSH) receptor 268 was constructed and injected into the bilateral gastrocnemius of experimental group mice at weeks 1, 4, 7 and 10. Equal volumes of saline were injected into the control and blank groups at the same time. The experimental and control groups were subjected to EP at the same time and location to enhance immunization. The levels of total serum thyroxine (T₄) and serum TSH were examined by radioimmunoassay and immunoradiometric assay, respectively. The levels of serum thyrotropin receptor N-terminal (TRAb N) and C-terminal (TRAb C) antibodies were assessed by ELISA. Whole body pertechnetate (99mTcO₄-) imaging was performed. Mouse weight and thyroid morphology and pathology were analyzed. The GD BALB/c mouse model was successfully established, with a positive rate of 79.17% (38/48). T₄ levels increased from baseline levels of 12.05±4.23 to 52.51±23.58 ng/ml by week 12 (P<0.0001). TSH levels decreased from baseline levels of 5.53±2.78 to 1.43±0.89 µIU/ml by week 12 (P<0.0001). TRAb N antibody levels increased from baseline levels of 0.006±0.002 to 0.278±0.106 mIU/ml by week 12 (P<0.0001). TRAb C antibody levels increased from baseline levels of 11.111±2.808 to 46.701±26.436 arbitrary units/ml by week 12 (P<0.0001). At week 21, TSH levels remained reduced compared with pre-immunization levels (P<0.0001). Although T₄, and TRAb N and C levels decreased, they remained increased compared with preimmunization levels (P<0.0001, P<0.0001, P=0.001). There were no significant alterations in antibody levels between the control and blank groups. Following four immunizations, the uptake of 99mTcO₄- by the thyroid was significantly increased in the experimental group. The mean weight of the experimental mice was significantly reduced compared with the control and blank groups (all P<0.0001). Furthermore, the thyroid glands of the immunized mice were enlarged and exhibited lymphocyte infiltration, fewer colloid nodules and an increased height of epithelial cells. In conclusion, by injecting recombinant plasmid pcDNA3.1/TSHR268 and EP, a GD mouse model was successfully established.

Clinical and Dosimetric Variables Related to Outcome After Treatment of Graves' Disease With 550 and 1110 MBq of 131I: Results of a Prospective Randomized Trial

: Therapy of Graves' hyperthyroidism (HTG) with I is still mostly performed on an empirical basis. The present study was carried out to evaluate clinical and dosimetric variables associated with outcome in HTG therapy, which could contribute to planning and defining the most appropriate activity to be administered.

METHODS

Patients with HTG were randomly assigned to therapy with 555 MBq (15mci) or 1110 MBq (30 mCi) of I. Estimation of thyroid radiation absorbed dose was made according to MIRD methodology. Success was defined as clinical/laboratory euthyroidism or hypothyroidism one year after therapy. The association between clinical, laboratory, and dosimetric variables with 1-year outcome was measured using bivariate analysis, followed by logistic regression.

RESULTS

Ninety-one patients included completed the follow-up. Therapeutic success was observed in 77 (84.6%) of them, in a greater proportion when 1110 MBq of I was administered as compared with 550 MBq (94.8% vs 77.4%, P = 0.02). Besides administered activity, multivariate analysis indicated that outcome was related to patient age and gland mass. A higher therapeutic success rate was achieved with doses greater than 300 Gy as compared with doses less than 300 Gy (89% vs 60%, P = 0.01).

CONCLUSION

Administered activity, age, and gland mass were related to the outcome. Radiation absorbed dose, although not significant according to multivariate analysis, may be used as a quantitative parameter in therapy planning, with a target dose of 300 Gy. In cases where a rapid and efficient response to radioiodine treatment is required, adoption of a simplified protocol employing high activities is justified.

Wenxin Keli versus Sotalol for Paroxysmal Atrial Fibrillation Caused by Hyperthyroidism: A Prospective, Open Label, and Randomized Study

We aimed to compare effectiveness of Wenxin Keli (WK) and sotalol in assisting sinus rhythm (SR) restoration from paroxysmal atrial fibrillation (PAF) caused by hyperthyroidism, as well as in maintaining SR. We randomly prescribed WK (18 g tid) or sotalol (80 mg bid) to 91 or 89 patients. Since it was not ethical not to give patients antiarrhythmia drugs, no control group was set. Antithyroid drugs were given to 90 patients (45 in WK group, 45 in sotalol group); ¹³¹I was given to 90 patients (46 in WK group, 44 in sotalol group). Three months later, SR was obtained in 83/91 or 80/89 cases from WK or sotalol groups (P = 0.762). By another analysis, SR was obtained in 86/90 or 77/90 cases from ¹³¹I or ATD groups (P = 0.022). Then, we randomly assigned the successfully SR-reverted patients into three groups: WK, sotalol, and control (no antiarrhythmia drug was given) groups. After twelve-month follow-up, PAF recurrence happened in 1/54, 2/54, and 9/55 cases, respectively. Log-Rank test showed significant higher PAF recurrent rate in control patients than either treatment (P = 0.06). We demonstrated the same efficacies of WK and sotalol to assist SR reversion from hyperthyroidism-caused PAF. We also showed that either drug could maintain SR in such patients.

Differentiation between Graves' disease and painless thyroiditis by diffusion-weighted imaging, thyroid iodine uptake, thyroid scintigraphy and serum parameters

The aim of the present study was to assess the apparent diffusion coefficient (ADC) in diffusion-weighted imaging (DWI), thyroid radioactive iodine uptake (RAIU), thyroid scintigraphy and thyrotropin receptor antibody (TRAb) levels in the differential diagnosis between Graves' disease (GD) and painless thyroiditis (PT). A total of 102 patients with GD and 37 patients with PT were enrolled in the study. DWI was obtained with a 3.0-T magnetic resonance scanner, and ADC values were calculated. RAIU and thyroid scintigraphy were performed. Tissue samples were obtained from patients with GD (6 cases) following thyroidectomy, and from patients with PT (2 cases) following biopsy. Receiver operating characteristic (ROC) curves were drawn, optimal cut-off values were selected, and the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were assessed. It was found that the ADC, TRAb and RAIU were significantly higher in GD than in PT (P<0.05). ROC curves showed areas under the curves for RAIU, ADC and TRAb that were >0.900. RAIU was the reference method. Sensitivity, specificity, accuracy, PPV and NPV were 96.078, 91.892, 95.000, 97.059 and 89.474% for ADC, and 88.235, 75.676, 84.892, 90.909 and 70.000% for TRAb, after the optimal thresholds of 1.837×10^-3 mm²/sec and 1.350 IU/ml were determined respectively. Histopathology showed that tissue cellularity in PT was much higher than in GD due to massive lymphocytic infiltration. The results of the present study indicate that RAIU, ADC and TRAb are of diagnostic value for differentiating between GD and PT. DWI has great potential for thyroid pathophysiological imaging because it reflects differences in tissue cellularity between GD and PT.

[Efficacy of treatment with I(131) in paediatric Graves disease]

INTRODUCTION

Radioiodine is an important therapeutic option in young patients with Grave's disease (GD). In the United States it is a widespread therapy, but in Europe its use in paediatrics is still controversial.

AIM

To report our experience in radioiodine therapy of paediatric GD patients and analyse its effectiveness and safety.

PATIENTS AND METHODS

We retrospectively studied our paediatric population (<18 years of age) with GD, diagnosed from 1982 to 2012. A curative option was offered to patients who did not respond to anti-thyroid drug (AT) at puberty. We analysed, the patient characteristics, TSH, T4, T3 and thyroid antibodies levels, AT response, remission post I(131), side effects, and hypothyroidism rates.

RESULTS

A total of 50 patients were diagnosed with GD from 1982 to 2012. All patients received AT as initial treatment (mean duration: 35.3±25.9 months). Permanent remission was achieved in 46%. Thyroidectomy was performed in 5 patients, and 14 patients received I(131) (mean dose: 10.9±1.09 mCi). Remission with I(131) was obtained in 100%. The rate of permanent hypothyroidism was 90%. There was no progression of ophthalmopathy or side effects in any patients treated with I(131.)

CONCLUSION

Radioiodine treatment of paediatric GD patients is safe, leads to complete remission at the expense of hypothyroidism, and does not exacerbate ophthalmopathy. It can be considered in patients older than 5 years, who do no not respond to AT or with significant side effects with this medication.