Prognostic factor analysis in 325 patients with Graves' disease treated with radioiodine therapy

Clinical factors influencing the success rate of radioiodine treatment for Graves' disease

AIMS

To investigate the impact of various clinical factors associated with Graves' disease on the success rate of radioiodine (RAI) therapy for Graves' disease within 3 years, and to determine the optimal range of iodine dosage per unit volume that yields the highest cure rate for Graves' disease within 1 year.

MATERIALS AND METHODS

This retrospective study included patients diagnosed with Graves' disease who underwent RAI therapy at the Second Affiliated Hospital of Anhui Medical University between October 2012 and October 2022. The cumulative success rate was analysed using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression models were employed to evaluate factors associated with successful treatment of Graves' disease. Outcomes were categorized as either success or failure for all patients.

RESULTS

Overall, 1994 patients were enrolled in this study, including 594 (29.8%) male and 1399 (70.2%) female patients. The success and failure groups comprised 1645 (82.4%) and 349 patients (17.6%), respectively, after a 3-year follow-up period. Multivariate regression analysis demonstrated that sex, antithyroid drug (ATD) use before RAI therapy, age, thyroid receptor antibody (TRAb) levels, iodine dose, thyroid mass, and early ATD use before RAI therapy were independent influencing factors for Graves' disease cure.

CONCLUSIONS

We found that female patients and those with TRAbs ≥31.83 IU/L and thyroid mass ≥ 73.42 g had a lower cure rate. Therefore, thyroid size, disease severity, and duration of disease should be comprehensively considered when making treatment decisions and iodine dose selection in clinical practice.

Radioactive Iodine Treatment of Graves' Disease: Predictors of Time Interval Greater than 90 Days for Treatment Success

Objective

Radioactive iodine (RAI) is often used for treating Graves' disease. We study predictors for a time interval greater than 90 days between RAI treatment and success.

Methods

This was a retrospective study of 106 patients with Graves' disease seen at a public hospital in suburban New York City. Predictor variables were from demographics, prior treatment history, iodine 131 RAI treatment, and thyroid function prior to RAI treatment.

Results

There were 62.3% that had a time interval greater than 90 days between RAI treatment and success. Only the thyroid function prior to RAI treatment variable of free thyroxine (FT4) had statistically significantly increased odds for time interval greater than 90 days between RAI treatment and success (OR:1.28, 95% CI:1.02, 1.61, p = 0.03). Demographics, prior treatment history, and iodine 131 RAI treatment variables were not significantly associated with time interval greater than 90 days between RAI treatment and success.

Conclusion

Thyroid function measured by FT4 was significantly associated with time interval greater than 90 days between RAI treatment and success. We suggest that the thyroid function variable of FT4 levels at initial diagnosis is most helpful for understanding the prognosis and success rate for using RAI treatment in patients with Graves' disease.

A retrospective study with long term follow-up of Graves' disease patients treated with low activities of 131Iodine

BACKGROUND

Previous studies have shown that application of relatively low 131I-Iodine activities can successfully be used to treat patients with Graves' disease (GD). We assessed treatment outcome in the long-term follow-up of our GD patients and influencing factors.

METHODS

We evaluated 521 GD patients in this retrospective clinical single-center study. In all patients we performed scintigraphy and thyroid uptake measurement after 4 and 24 hours using 10 MBq 123I and calculated administered activity using Marinellis' formula. Treatment was done according to national regulations. Minimal routine clinical evaluation of all patients was available after 6 weeks and after 3, 6 and 12 months. Success of treatment was defined as euthyroid state or hypothyroidism 6 months after therapy.

RESULTS

We usually applied relatively low 131I activities. Three hundred seven patients (58.9%) became hypothyroid within 21 years of follow-up. One hundred thirty-nine patients (26.7%) became euthyroid and stayed euthyroid until the end of follow-up. We found a plateau after 7 years of initial therapy with only a few patients becoming hypothyroid after that time and identified 75 patients (14.4%) with persistent hyperthyroidism or recurrence.

CONCLUSIONS

Treatment with relatively low 131I activities produce favorable responses as shown in previous works. We found a high proportion of patients with long-term euthyroid state. Application of low activities reduces radiation burden of patients and, depending on radiation protection legislation, may lead to shortened hospital stay and reduced costs. Therefore, we feel that application of higher activities to treat GD patients as recommended in several current guidelines should be reconsidered.

Factors affecting timing of hypothyroidism following radioactive iodine therapy (RAIT) for patients with Graves' disease: A 12-month observational study

BACKGROUND

This retrospective study analyzed factors influencing hypothyroidism development after radioactive iodine therapy for Graves' disease.

PATIENTS AND METHODS

Three hundred and three patients with Graves' disease treated with radioactive iodine (RAI) from 2013 to 2022 at two Egyptian hospitals were included. Data collected included demographics, lab values, thyroid imaging, RAI doses, and outcomes. Patients were followed for ≥1 year to assess hypothyroidism onset.

RESULTS

At the end of 1 year, around 79.5% of the individuals developed hypothyroidism while 12.5% continued to experience hyperthyroidism. The onset of hypothyroidism occurred earlier in those with thyroid volume (≤75.5 cm 3 ), lower thyroid weight (≤84.7 g), thyroid uptake (≤18.8%), and higher RAI dose/volume (≥0.1022 mCi/ml) ( P  < 0.001). Additionally, there was a correlation between anti-thyroid peroxidase (anti-TPO) antibodies and faster development of hypothyroidism compared to those who were negative for antibodies (2.9 vs 8.9 months, P  = 0.001). When considering factors in analysis it was found that anti-TPO antibodies were the only independent predictor, for developing hypothyroidism (hazard risk 30.47, P  < 0.001). Additionally, thyroid volume and uptake independently predicted successful treatment outcomes ( P  < 0.05).

CONCLUSION

Positive anti-TPO antibodies strongly predict hypothyroidism risk after RAI therapy for Graves' disease. Smaller thyroid size, lower uptake, and higher RAI dose/volume correlate with earlier hypothyroidism onset but are less significant predictors than anti-TPO status. Findings can guide RAI therapy personalization to optimize outcomes.

Ultrasound combined with Ki-67 to construct the prognostic model for radioactive iodine therapy outcomes in Graves' disease patients

The aim of this study was to develop a prognostic model for radioactive iodine (RAI) therapy outcome in patients with Graves' disease. We enrolled 127 patients. Information on RAI therapy, ultrasound indexes of thyroid, and other lifestyle factors was collected. The competing risk model was used to estimate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for nonhealing or recurrence of hyperthyroidism (NHRH). The performance of the model was assessed by receiver operator characteristic analysis and the Brier score and internally validated by bootstrap resampling. Then, a nomogram was developed. Forty-one cases (32.2%) of NHRH were documented. Positive Ki-67 expression, a higher dose of per-unit thyroid volume, and females showed lower risks of NHRH (all P < 0.05). The HR values (95% CI) were 0.42 (0.23, 0.79), 0.01 (0.00, 0.02), and 0.47 (0.25, 0.89), respectively. The bootstrap validation showed that the model had the highest accuracy and good calibration for predicting cumulative risk of NHRH at 180 days after RAI therapy (AUC = 0.772; 95% CI: 0.640-0.889, Brier score = 0.153). By decision curve analysis, the nomogram was shown to have a satisfactory net benefit between thresholds of 0.20 and 0.40. Ki-67, ultrasound volumetry, and scintigraphy techniques can play important roles in evaluating RAI therapy outcome in Graves' disease patients. The prediction nomogram shows reasonable accuracy in predicting NHRH.

[Ultrasound combined with Ki67 detection for analyzing contributing factors of failure to cure and recurrence of hyperthyroidism in patients with Graves disease after 131I treatment]

OBJECTIVE

To analyze factors associated with failure to cure or recurrence of hyperthyroidism in patients with Graves disease (GD) after 131I treatment using ultrasound combined with Ki67 detection.

METHODS

Eighty-nine patients with GD receiving 131I treatment in the Department of Nuclear Medicine at our hospital from January, 2020 to November, 2021 were enrolled. Before treatment, thyroid volume, shear wave elastic value and Ki67 expression in the follicular epithelial cells were measured using three-dimensional ultrasonic virtual organ computer-aided analysis, shear-wave elastic imaging and ultrasound-guided fine needle aspiration. The data including age, gender, antithyroid drug (ATD) history, dose of 131I, and TRAb were collected from all the cases. The patients were followed up for up to 1 year, starting at 1 month after 131I treatment, and the follow-up results of the patients were divided into failure to cure or recurrence of hyperthyroidism, premature hypothyroidism and euthyroidism or loss to follow-up. The proportional hazards model and fine-Gray test were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (95% CI) for patients with failure to cure or recurrence of hyperthyroidism.

RESULTS

Among the 89 patients, 27 patients were found to have failure to cure or recurrence of hyperthyroidism, 50 had premature hypothyroidism, 1 patient had euthyroidism, and 11 patients were lost to follow-up at the end of the 1-year follow-up. Analysis of the competitive risk model showed that status of Ki67 expression, 131I dose and thyroid volume were independently correlated with failure to cure or recurrence of hyperthyroidism after the treatment with HR (95% CI) of 0.36 (0.15, 0.86), 0.81 (0.68, 0.96) and 1.11 (1.07, 1.15), respectively.

CONCLUSION

In patients with GD, the expression of Ki67 in thyroid follicular epithelial cells, 131I dose and thyroid volume are independently correlated with failure to cure or recurrence of hyperthyroidism after 131I treatment. New ultrasound techniques can play an important role in evaluating the therapeutic outcome of 131I treatment in GD patients.

Clinical Outcomes of Repeated Radioactive Iodine Therapy for Graves' Disease

BACKGRUOUND

Radioactive iodine (RAI) therapy is a successful therapeutic modality for Graves' disease. However, RAI therapy can fail, and RAI therapy after antithyroid drugs (ATDs) has a lower remission rate. Therefore, many patients require repeated RAI therapy. This study investigated the clinical outcomes of repeated RAI therapy for Graves' disease.

METHODS

Patients who underwent RAI therapy as second-line therapy after failure of ATD treatment between 2001 and 2015 were reviewed. Remission was defined as hypothyroid or euthyroid status without ATD, and with or without levothyroxine at 12 months after RAI therapy.

RESULTS

The 1-year remission rate after 2nd RAI therapy (66%, 152/230) is significantly higher than that after 1st RAI therapy (48%, 393/815) or long-term ATD treatment after 1st RAI therapy failure (42%). The clinical response to 2nd RAI therapy was more rapid. The median time intervals from the 2nd RAI therapy to ATD discontinuation (1.3 months) and to the start of levothyroxine replacement (2.5 months) were significantly shorter than those for the 1st RAI therapy. A smaller goiter size, a longer time interval between the 1st and 2nd RAI therapies, and a longer ATD discontinuation period predicted remission after the 2nd RAI therapy. Finally, in 78 patients who failed the 2nd RAI therapy, the mean ATD dosage significantly reduced 5.1 mg over 12 months.

CONCLUSION

Repeated RAI therapy can be a good therapeutic option, especially in patients with smaller goiters and those who are more responsive to the 1st RAI therapy.

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.

Meta-Analysis of Randomized Controlled Trials Comparing the Efficacy of Radioactive Iodine Monotherapy versus Radioactive Iodine Therapy and Adjunctive Lithium for the Treatment of Hyperthyroidism

Background: The objective of this article is to evaluate the outcomes in patients undergoing radioactive iodine (RAI) with adjunctive lithium (Li) therapy versus (vs.) RAI therapy alone for the treatment of hyperthyroidism.Methods: A systematic review of the literature was undertaken to analyze clinical trials comparing RAI with adjunctive Li therapy vs. RAI therapy alone for the treatment of hyperthyroidism.Results: Six randomized-controlled trials (RCT) involving 755 patients were analyzed. RAI with adjunctive Li was associated with a significantly higher cure rate for hyperthyroidism when compared to RAI alone. Furthermore, a significantly higher cure rate for hyperthyroidism at 12 months was achieved with RAI and adjunctive Li. Adjuvant Li with RAI for ≤ 7 days showed significantly higher cure rate compared to RAI alone, whereas > 7 days of adjuvant Li with RAI did not show any difference in cure rate compared to RAI alone. RAI with adjunctive Li was associated with a significantly higher cure rate for patients with Graves' disease compared to RAI alone. There was no significant difference between RAI with adjunctive Li and RAI alone for toxic nodular thyroid disorder (toxic nodule and toxic multinodular goiter) and thyroid volume >40 grams and ≤40 grams.Conclusions: RAI with adjunctive Li therapy demonstrated superiority over RAI therapy alone with regards to both curing hyperthyroidism and, reduced time till cure, with a limited side effect profile. A large multicenter RCT is required, and if this confirms the data from these smaller trials, then this could change current practice.

Predictive factors of radioiodine therapy failure in Graves' Disease: A meta-analysis

BACKGROUND

I-131 therapy is a common treatment modality for adults with Graves' Disease (GD). Utilizing meta-analysis, we examined patient specific factors that predict I-131 therapy failure.

METHODS

Literature search followed PRISMA. Comprehensive Meta-analysis (version 3.0) was used. Mantel-Haenszel test with accompanying risk ratio and confidence intervals evaluated categorical variables. Continuous data was analyzed using inverse variance testing yielding mean difference or standardized mean difference. Decision tree algorithms identified variables of high discriminative performance.

RESULTS

4822 collective patients across 18 studies were included. Male sex (RR = 1.23, 95%CI = 1.08-1.41, p = 0.002), I-131 therapy 6 months after GD diagnosis (RR = 2.10, 95%CI = 1.45-3.04, p < 0.001) and history of anti-thyroid drugs (RR = 2.05, 95%CI = 1.49-2.81, p < 0.001) increased the risk of I-131 therapy failure. Elevated free thyroxine, 24-h radioactive iodine uptake scan ≥60.26% and thyroid volume ≥35.77 mL were also associated with failure.

CONCLUSION

Patient characteristics can predict the likelihood of I-131 therapy failure in GD. Definitive surgical treatment may be a reasonable option for those patients.

Age moderates the associations between TRAbs, free T3 and outcomes of Graves' disease patients with radioactive iodine treatment

OBJECTIVE

This study aimed to explore whether age moderates the associations between TSH receptor antibodies (TRAbs) with thyroid hormones and remission in patients with Graves' disease (GD) who undergo radioactive iodine (RAI) treatment.

DESIGN

A single-centre retrospective study.

PATIENTS

A total of 435 eligible consecutive patients diagnosed with GD and treated with RAI therapy were included.

METHODS

TRAbs and thyroid hormones prior to RAI were recorded. Pearson's correlation, t tests and analysis of covariance were conducted to identify the associations between TRAbs, thyroid hormones and remission. Moderation analyses were conducted to test age as a moderator.

RESULTS

Overall, 75.4% of the patients achieved remission with a single dose of iodine-131. TRAb levels before RAI were positively correlated with the circulating thyroid hormones (ps < 0.001). Age moderated the association between TRAbs and free T3 (FT3) (P = .01), but did not moderate the association between TRAbs and free T4 (FT4) (P = .07). TRAb levels before RAI only significantly predicted remission status in young patients (P = .03), but not in middle-aged (P = .36) or older patients (P = .74), after adjusting for covariates. When age was included as a continuous variable, moderation analyses revealed that the association between TRAbs and remission status was stronger in younger patients (P = .03).

CONCLUSIONS

The majority of Graves' disease patients experienced a long-term remission following a single dose of iodine-131. Associations between TRAbs, FT3 and remission are moderated by age. TRAb level prior to RAI is a significant remission in younger patients, but not in middle-aged or older patients.

[Radiological Technology for Targeted Radionuclide Therapy]

Targeted radioisotope therapy (TRT) is a radiotherapy using radioisotope or drug incorporating it and has been used as a treatment for selectively irradiating cancer cells. In recent years, interest in TRT has increased due to improvements in radionuclide production technology, development of new drugs and imaging modalities, and improvements in radiation technology. In order to enhance the effect of TRT, measurement of individual radiation doses to tumor tissue and organs at risk is important using highly quantitative nuclear medicine images. In this paper, we present a review of literature on optimization of TRT, which is a new research area from the perspective of radiation technology.

Effectiveness of radioactive iodine (131I) in the treatment of Graves' disease: single center experience in Assiut University hospital

To evaluate the effectiveness of radioactive iodine (¹³¹I) therapy in patients with Graves' disease (GD) in Assiut University Hospital. We retrospectively evaluated two hundred and seven patients with GD, after their therapy with ¹³¹I. Before therapy all the included patients underwent neck ultrasound, hormonal assay and ^99mTechnetium-pertechntate (^99mTc) thyroid scintigraphy to evaluate percentage uptake of the thyroid gland, after therapy all patients followed up clinically and laboratory every 3 months for at least one year to detect outcome; where euthyroid or hypothyroid status denotes successful therapy. Successful outcome obtained in 165/207 patients representing 79.7% of the study population while in the remaining 42 (20.3%) patients a second dose was required. In Univariate analysis only dose of ¹³¹I and previous thyroid surgery are the important factors (P value = 0.003 and 0.001 respectively). We concluded that ¹³¹I therapy is highly effective and cost-effective method for treatment of GD, higher doses are associated with higher success rate.

[Role and effectiveness of radioactive-iodine therapy for the treatment of Grave's disease]

The treatment of Graves' disease is based on three therapies: medical treatment with synthetic antithyroid agents, surgery and radioactive-iodine therapy. The purpose of our study was to study the role and effectiveness of radioactive-iodine therapy for the treatment of Graves' disease. We conducted a retrospective, descriptive study of the epidemiological, clinical, paralclinical and therapeutic features of 54 patients with Graves' disease managed and treated with iodine-131 as well as of their short- and medium-term remission rate. The sex ratio was 0.45. The average age of patients was 38,33 ± 12.7 years. The most common functional signs were weight loss, tremors and palpitations. Mean FT4 was 54,51 ± 19,56 ng/dl (ranging from 8,90 and 100). Mean TSHus was 0,074 ± 0,29 µIU/ml. Synthetic antithyroid drugs were used in 49 patients; 83,67% of cases had persistent hyperthyroidism. Radioactive-iodine therapy was used as first-line therapy in 9,3% of cases and as second-line therapy in 90,7% of cases. Mean activity was 13,29 mCi ± 1,46 ranging from 10 to 15 mCi. The first assessment of hormonal status was performed after an average post-treatment period of 1,91 months; 29 patients (53,7%) achieved remission (eu- or hypo-thyroidism). After a 12 month-follow-up, patients' course was marked by remission in 88,88% of cases (euthyroidism in 14,8% and hypothyroidism in 74% of cases). Radioactive-iodine therapy is an effective treatment for Graves' disease. High radioactive iodine dose provides high remission rate.

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.

Long-term outcome and prognostic factors of single-dose Radioiodine Therapy in patients with Graves' disease

BACKGROUND/PURPOSE

Few studies exist investigating the effectiveness of radioiodine (RAI) therapy for hyperthyroidism patients in Asia. We herein investigated the real-world efficacy of single-dose RAI therapy in Taiwanese patients with Graves' disease (GD).

METHODS

This is a retrospective study of 243 patients with GD recorded between 1989 and 2016 in a tertiary referral hospital. Eu- or hypothyroid after RAI therapy were defined as the successful group. Kaplan-Meier curve and cox-regression model were used for analysis of prognostic factors.

RESULTS

Of the 243 patients, 187 were females, with mean age of 46.9 ± 13.6 years. Most patients (63.8%) did not choose RAI as the first-line therapy. The median dose was 7 mCi, with a mean follow-up period of 107.1 ± 82.8 months. The overall success rate was 70.9%. Univariate analysis revealed calculated- or fixed-dose (P = 0.015), goiter size (P < 0.001), and RAI dose (P = 0.022) were the factors affecting RAI effectiveness, multivariate analysis indicated goiter size was the independent factor. Patients with grade 0-2 goiter had a higher success rate than patients with grade 3 goiter (HR = 2.1, 95%CI = 1.34-3.27, P = 0.001), although the former were treated with lower RAI dose than the latter (7.8 ± 3.2 mCi vs 8.8 ± 3.3 mCi, P = 0.049). However, if the grade 3 goiters became smaller within 3 months of therapy, the success rate was not inferior to grade 0-2 goiter.

CONCLUSION

In Taiwan, RAI therapy for GD patients reached an overall success rate of 70.9%, with a median dose of 7 mCi. This study identified patients with grade 3 goiter need a more aggressive RAI regimen.

Radiosensitivity-related postirradiation hypothyroidism in Graves' disease patients

PURPOSE

The cumulative incidence of hypothyroidism, in ¹³¹I-treated patients with hyperthyroidism caused by Graves' disease, has been gradually increasing each year. Meanwhile, the role of the genes that control radiation sensitivity (GCRS) involved in ¹³¹I therapy is yet to be defined. The main purpose of the present study is to find GCRS that could indicate hypothyroidism in Graves' disease patients treated with ¹³¹I.

METHODS

Thyroid tissue was collected from 59 patients who were diagnosed with Graves' disease. GCRS (including Bcl-2, NF-κB, Survivin, Ku-70, Tob1, EGFR, Egr-1, TP-53, BRCA-1, and ATM) mRNA levels were analyzed with qRT-PCR before radioiodine therapy. Patients were followed up and then grouped by end-point outcomes. The association of the variation of target genes with susceptibility to hypothyroidism was analyzed.

RESULTS

Altogether 44 patients were enrolled, including 11 men and 33 women with an average age of 44.79 ± 12.94 years. Based on their clinical outcomes after at least 2-year follow-up, 59% (26/44) patients were evaluated as hypothyroid, while the remaining 41% (18/44) patients were non-hypothyroid, including 18% (8/44) with persistent hyperthyroidism. The hypothyroid group showed significantly lower Ku-70 mRNA expression levels than the non-hypothyroid group (p = 0.022), whereas no significance was detected regarding other target genes (p > 0.1). Multivariate analysis showed that Ku-70 was significantly correlated with hypothyroidism after ¹³¹I treatment (p = 0.033).

CONCLUSIONS

The opposing changes in mRNA expression levels of Ku-70 in patients with hypothyroidism indicate its potential as a prognostic marker for hypothyroidism induced by ¹³¹I treatment.

Apoptosis gene reprograming of human peripheral blood mononuclear cells induced by radioiodine-131 (131I) irradiation

Background & objectives

The nature of adaptable change of B-cell lymphoma-2 (BCL-2) and/or Bcl2-associated X protein (BAX) gene expression in the human peripheral blood mononuclear cells (PBMCs) irradiated by radioiodine in thyroid diseases therapy is not fully understood. In this study, the alternation of apoptotic gene expression was evaluated while the PBMCs collected from healthy volunteers were irradiated by the radioiodine-131 (¹³¹I).

Methods

Fasting blood samples were obtained from healthy volunteers. PBMCs from group 0 to 6 were incubated and exposed to different doses of ¹³¹I in cell suspension for 6, 12, 24 and 48 h. The apoptosis rates and expression of BCL-2 and BAX genes of PBMCs were examined.

Results

The apoptosis rate in the human PBMCs was gradually enhanced after six hour irradiation. The values of BCL-2 and BAX gene expression in groups 1-6 were higher than in group 0 within 6 h of irradiation, and then, these were decreased gradually from 6 to 12 h.

BCL

-2 gene expression increased in groups 1-3 after 12 h irradiation, but there was no difference in groups 4-6. The ratio of BCL-2/BAX gene expression among groups 4-6 gradually decreased during the period from 6 to 12 h, and it was significantly lower than in the group 0 at 12, 24 and 48 h.

Interpretation & conclusions

The expression of BCL-2 and BAX genes was initially upregulated following irradiation. Later, the balance of BCL-2/BAX genes expression was adjusted, and then, PBMCs underwent apoptosis at higher doses of radiation.

Radioiodine treatment for graves' disease: a 10-year Australian cohort study

BACKGROUND

Radioactive iodine (I131) is a common definitive treatment for Graves' Disease. Potential complications include worsening, or new development of Graves' eye disease and development of a radiation thyroiditis. The purpose of the present study was to assess outcomes of patients treated with I131 in an Australian tertiary centre over 10 years.

METHODS

Data from 101 consecutive patients treated with I131 for a diagnosis of Graves' disease between 2005 to 2015 was collected and reviewed retrospectively. Baseline TSH receptor antibody titre, pre-treatment free thyroxine (FT4), technetium scan uptake, initial treatment, duration of treatment, reason for definitive therapy, complications, and time to remission (defined as euthyroidism or hypothyroidism after 12 months) were recorded.

RESULTS

Of the 92 patients with adequate outcome data, 73 (79.3%) patients achieved remission with a single dose of I131. Of the remaining 19 patients, 12 had a second dose and became hypothyroid. TSH receptor antibody titre at diagnosis was significantly lower in the group that achieved remission with the first dose compared with those who did not (P = 0.0071). There was no difference in technetium uptake, I131 dose, duration of therapy or pre-treatment free thyroxine (FT4). I131 was complicated by development of eye disease in 3 patients and 1 (of 11 with pre-existing eye disease) had worsening eye disease. A clinically apparent flare of hyperthyroidism following I131 was evident in 8 patients (8.6%).

CONCLUSION

Radioiodine is an effective therapy for Graves' Disease with few complications. The majority of patients achieve remission with a single dose. Those who require a second dose are more likely to have higher TSH receptor antibody titres at diagnosis. To the best of our knowledge, this is the first study to report outcomes from radioiodine treatment for Graves' disease in an Australian population.

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.