Controversies in the management of Graves' disease

Success rate of radioactive iodine treatment for children and adolescent with hyperthyroidism

PURPOSE

To assess the success rate of first dose radioiodine for treatment of hyperthyroidism in children and adolescent.

METHODS

This is a retrospective data analysis of children and adolescent with hyperthyroidism who received radioiodine (RAI) therapy from January 2013 to December 2017. Age, gender, family history of hyperthyroidism, duration of anti-thyriod drugs (ATDs) treatment, rapid turnover status, 2 h and 24 h I-131 radioiodine uptake (RAIU), thyroid volume, and treatment dose were also analyzed. The goal of RAI therapy was to achieve hypothyroidism within 3-6 months after treatment. Treatment result was evaluated at 6 months after treatment and divided into 2 groups: treatment success (hypothyroid and euthyroid) and treatment failure (hyperthyroid). The same parameters were compared between both groups.

RESULTS

32 hyperthyroid patients, 26 female with mean age at treatment of 13.84 ± 1.83 years. All patients had prior treatment with ATDs, with a median treatment duration of 32.5 months (range 2-108). The median estimated thyroid gland size was 24.62 g, range 9.29-72.8. RAI doses ranged from 4.1 to 29.9 mCi (median dose = 7.54 mCi). Significant difference in 24-h I-131 uptake and RI status was demonstrated. Successful treatment rate after single dose of therapeutic I-131 was 65.63%.

CONCLUSION

With the I-131 dose of 220 μCi/g of thyroid tissue, successful treatment rate after single dose of therapeutic I-131 was 65.63%. RAI therapy with I-131 dose of 250-400 μCi/g of thyroid tissue might be suitable in patients with medical failure from ATDs. Possible role of RI as the predictor for RAI therapy failure are needed to investigate in both adult and children clinical settings.

Graves' disease: Introduction, epidemiology, endogenous and environmental pathogenic factors

Graves' disease is the most frequent cause of hyperthyroidism. Many questions remain about the choice of diagnostic evaluations and treatment strategy according to clinical context (age, gender, pregnancy, etc.) and about the best management of the main extrathyroidal complication that is Graves orbitopathy. The exact pathogenic mechanisms are not fully clear. They associate genetic factors, interactions between endogenous and environmental factors, and immune system dysregulation. Graves' orbitopathy is one of the consequences of this partial understanding. Iatrogenic Graves' disease induced by the new targeted therapies are described and could help to better understand the molecular pathways involved in the disease and to develop new therapeutic approaches.

Radioiodine thyroid ablation in graves' hyperthyroidism: merits and pitfalls

Ablative approaches using radioiodine are increasingly proposed for the treatment of Graves′ disease (GD) but their ophthalmologic and biological autoimmune responses remain controversial and data concerning clinical and biochemical outcomes are limited. The aim of this study was to evaluate thyroid function, TSH-receptor antibodies (TRAb) and Graves′ ophthalmopathy (GO) occurrence after radioiodine thyroid ablation in GD. We reviewed 162 patients treated for GD by iodine-131 (¹³¹I) with doses ranging from 370 to 740 MBq, adjusted to thyroid uptake and sex, over a 6-year period in a tertiary referral center. Collected data were compared for outcomes, including effectiveness of radioiodine therapy (RIT) as primary endpoint, evolution of TRAb, and occurrence of GO as secondary endpoints. The success rate was 88.3% within the first 6 months after the treatment. The RIT failure was increased in the presence of goiter (adjusted odds ratio = 4.1, 95% confidence interval 1.4–12.0, P = 0.010). The TRAb values regressed with time (r = −0.147; P = 0.042) and patients with a favorable outcome had a lower TRAb value (6.5 ± 16.4 U/L) than those with treatment failure (23.7 ± 24.2 U/L, P < 0.001). At the final status, 48.1% of patients achieved normalization of serum TRAb. GO occurred for the first time in 5 patients (3.7%) who were successfully cured for hyperthyroidism but developed early and prolonged period of hypothyroidism in the context of antithyroid drugs (ATD) intolerance (P = 0.003) and high TRAb level (P = 0.012). On the basis the results of this study we conclude that ablative RIT is effective in eradicating Graves’ hyperthyroidism but may be accompanied by GO occurrence, particularly in patients with early hypothyroidism and high pretreatment TRAb and/or ATD intolerance. In these patients, we recommend an early introduction of LT4 to reduce the duration and the degree of the radioiodine-induced hypothyroidism.

Greater Efficacy of Total Thyroidectomy versus Radioiodine Therapy on Hyperthyroidism and Thyroid-Stimulating Immunoglobulin Levels in Patients with Graves' Disease Previously Treated with Antithyroid Drugs

AIMS

We compared the effects of total thyroidectomy (TTx) and radioiodine (RAI) administration on the course of thyroid hormones and thyroid-stimulating immunoglobulins (TSI) in patients with Graves' disease.

METHODS

We retrospectively studied 80 patients initially treated with antithyroid drugs and requiring either RAI (8.3 ± 1.7 mCi of (131)I; n = 40) or TTx (n = 40) as second-line therapy.

RESULTS

The TTx and RAI groups were not different, except for larger goiter, higher FT3 and more frequent Graves' orbitopathy at diagnosis in the surgery group (p < 0.05). A persistent remission of hyperthyroidism was observed in 97% of operated patients versus 73% of the RAI patients at 3 years (p < 0.01). TTx was followed by a rapid and steady decrease in TSI during the first 9 months, while a surge of antibodies was observed during the first 6 months after RAI, followed by a slow decrease over the next 18 months. At the last visit, high TSI levels were still observed in 18 and 60% of patients in the surgery and RAI groups, respectively (p < 0.001).

CONCLUSIONS

TTx is more efficient than RAI to induce a rapid and permanent correction of hyperthyroidism and TSI decrease in patients previously treated with antithyroid drugs.

Graves' ophthalmopathy as an indication increased the risk of hypoparathyroidism after bilateral thyroidectomy

Background

Studies have evaluated the effect of thyroidectomy on the course of Graves’ ophthalmopathy (GO) but it is unclear how GO as an indication might affect surgical outcomes. We aimed to evaluate the impact of this indication on surgical outcomes in Graves’ disease (GD).

Methods

From 1995 to 2008, 329 patients with GD underwent thyroidectomy. Patients were stratified into two groups, namely, those with GO as indication (GO) and those with non-GO indication (non-GO). Outcomes were compared between the groups and outcomes with significance were further analyzed by multivariate analyses to determine independent factors.

Results

The GO group was significantly older (P < 0.001), had more males (P < 0.001), and fewer relapses (P < 0.001) than the non-GO group. It also had a higher proportion of total/near-total thyroidectomy (P < 0.001), despite a shorter operating time (P = 0.024) and less blood loss (P = 0.010). When only total/near-total thyroidectomy was considered, the GO group had significantly more permanent hypoparathyroidism than the non-GO group (9.2 vs. 1.6%, P = 0.038), but the rate of permanent hypoparathyroidism was similar in the two groups when only those with parathyroid autotransplantation were considered. Other complications were similar between the two groups. By multivariate analysis, GO as indication was an independent risk factor for temporary (OR 1.97, P = 0.033) and permanent hypoparathyroidism (OR 4.76, P = 0.007).

Conclusion

GO as a surgical indication (i.e., unstable or active GO requiring ophthalmic treatment or follow-up) was associated with increased risk of temporary and permanent hypoparathyroidism after bilateral thyroidectomy. Routine parathyroid autotransplantation may reduce the risk of permanent hypoparathyroidism in this select patient group.

Orbital decompression for Graves' orbitopathy in England

AIMS

The purpose of this study was to obtain data on orbital decompression procedures performed in England, classed by hospital and locality, to evaluate regional variation in care.

METHODS

Data on orbital decompression taking place in England over a 2-year period between 2007 and 2009 were derived from CHKS Ltd and analysed by the hospital and primary care trust.

RESULTS AND CONCLUSIONS

In all, 44% of these operations took place in hospitals with an annual workload of 10 or fewer procedures. Analysis of the same data by primary care trust suggests an almost 30-fold variance in the rates of decompression performed per unit population. Expertise available to patients with Graves' orbitopathy and rates of referral for specialist care in England appears to vary significantly by geographic location. These data, along with other outcome measures, will provide a baseline by which progress can be judged.

Total thyroidectomy: a safe and effective treatment for Graves' disease

BACKGROUND

Thyroidectomy as a first line treatment for Graves' disease is rarely utilized in the US. The purpose of this study was to analyze the safety and efficacy of thyroid surgery among patients with Graves' disease.

METHODS

Fifty-six patients with Graves' disease underwent thyroid surgery between May 1994 and May 2008 at a single academic institution. Preoperative, intraoperative, and postoperative variables were analyzed.

RESULTS

A total of 58 surgeries were performed: 55.1% (n = 32) total thyroidectomy, 41.3% (n = 24) subtotal/lobectomy, 3.4% (n = 2) completion thyroidectomy. The average gland weight was 47.3 ± 10.8 gm, with 70% weighing > 30 gm. Reasons for having thyroid surgery were persistent disease despite medical therapy (46.6%), patient preference (24.1%), multinodular goiter/cold nodules (20.3%), failed RAI (radioactive iodine) treatment (16%), and opthalmopathy (12.1%). Of those patients that failed prior RAI therapy, the only factor that was predictive of failure was disease severity, as demonstrated by a markedly elevated initial free-T4 value (11.8 ± 4.5 ng/dL, P = 0.04). Transient symptomatic hypocalcemia occurred in 10.7% (n = 6) of patients, and one patient (1.8%) had symptomatic hypocalcemia lasting > 6 mo. There were no permanent recurrent laryngeal nerve injuries. There was no difference in overall complication rates between patients based on surgical procedure (subtotal versus total thyroidectomy), preoperative RAI treatment, or gland size. Recurrences occurred in 6% of the subtotal thyroidectomy group and 0% of the total thyroidectomy group (P = 0.008).

CONCLUSION

Thyroidectomy for patients with Graves' disease can be performed with very low complication rates and when a total thyroidectomy is performed, there is almost no risk of recurrence.

Antithyroid drug regimen for treating Graves' hyperthyroidism

BACKGROUND

Antithyroid drugs are widely used in the therapy of hyperthyroidism. There are wide variations in the dose, regimen or duration of treatment used by health professionals.

OBJECTIVES

To assess the effects of dose, regimen and duration of antithyroid drug therapy for Graves' hyperthyroidism.

SEARCH STRATEGY

We searched seven databases and reference lists.

SELECTION CRITERIA

Randomised and quasi-randomised trials of antithyroid medication for Graves' hyperthyroidism.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. Pooling of data for primary outcomes, and select exploratory analyses were undertaken.

MAIN RESULTS

Twenty-six randomised trials involving 3388 participants were included. Overall the quality of trials, as reported, was poor. None of the studies investigated incidence of hypothyroidism, changes in weight, health-related quality of life, ophthalmopathy progression or economic outcomes. Four trials examined the effect of duration of therapy on relapse rates, and when using the titration regimen 12 months was superior to six months, but there was no benefit in extending treatment beyond 18 months. Twelve trials examined the effect of block-replace versus titration block-regimens. The relapse rates were similar in both groups at 51% in the block-replace group and 54% in the titration block-group (OR 0.86, 95% confidence interval (CI) 0.68 to1.08) though adverse effects (rashes (10% versus 6%) and withdrawing due to side effects (16% versus 9%)) were significantly higher in the block-replace group. Three studies considered the addition of thyroxine with continued low dose antithyroid therapy after initial therapy with antithyroid drugs. There was significant heterogeneity between the studies and the difference between the two groups was not significant (OR 0.58, 95% CI 0.05 to 6.21). Four studies considered the addition of thyroxine alone after initial therapy with antithyroid drugs. There was no significant difference in the relapse rates between the groups after 12 months follow-up (OR 1.15, 95% CI 0.79 to 1.67). Two studies considered the addition of immunosuppressive agents. The results which were in favour of the interventions would need to be validated in other populations.

AUTHORS' CONCLUSIONS

The evidence suggests that the optimal duration of antithyroid drug therapy for the titration regimen is 12 to 18 months. The titration (low dose) regimen had fewer adverse effects than the block-replace (high dose) regimen and was no less effective. Continued thyroxine treatment following initial antithyroid therapy does not appear to provide any benefit in terms of recurrence of hyperthyroidism. Immunosuppressive therapies need further evaluation.

Prognostic value of thyrotropin receptor antibodies (TRAb) in Graves' disease: a 120 months prospective study

In most trials, at least 30-60% of patients with Graves' disease treated with antithyroid drugs relapse within 2 years after therapy withdrawal. At present, there are no prognostic parameters available early in treatment to indicate patients likely to achieve long-term remission. Because thyrotropin receptor autoantibodies (TRAb) are specific for Graves' disease, we evaluated the ability of their levels and of their rate of change to predict long-term prognosis. In our study 216 consecutive patients with newly diagnosed Graves' disease started a therapy with methimazole. Patients were treated until they achieved euthyroidism and TRAb were measured at 6-month intervals throughout a follow up of 120 months. Our study demonstrated that at the onset of hyperthyroidism patients' age, sex, fT4 levels and goiter size had no prognostic value in predicting long-term prognosis (respectively p = 0.79; p = 0.98; p = 0.83; p = 0.89). On the contrary, at the time of diagnosis TRAb titer was a good predictor of the final outcome (p<0.001); a titer equal to (or) more than 46.5 UI/L could identify patients who had never achieved long-term remission with a sensitivity of 52% and a specificity of 78%. Also fall rate of TRAb at 6 months of follow up and after therapy withdrawal were useful to predict the final outcome (p<0.001). At 6 months of follow up the time of therapy withdrawal, a decrease of TRAb lower than 52.3% or even its increase could identify patients who had never achieved permanent remission with a sensitivity of 55% and a specificity of 79.1%. No single parameter among TRAb, satisfactory identified a sub-set of patients who achieved long remission. Accordingly to our data, the best result in predicting long term remission is probably given by the presence of at least one of the two features evaluated at 6 months (TRAb titer and/or percentage of TRAb fall rate), with a sensitivity of 63% and specificity of 88%. TRAb titers evaluated both at the onset of hyperthyroidism that at 6 months of therapy or their rate of fall at 6 months and at ATD withdrawal are predictors of outcome. However, the presence of at least one, between titers of TRAb or their rate of fall at six months, resulted to be the best predictor of remission with the higher sensitivity and specificity.

Avaliação da radioiodoterapia com doses fixas de 10 e 15 mCi em pacientes com doença de graves

As opções terapêuticas para a hipertireoidismo da doença de Graves são as drogas antitireoidianas, a cirurgia e o radioiodo, porém nenhuma delas é considerada ideal pois não atuam diretamente na etiopatogênese da doença. O radioiodo vem sendo cada vez mais utilizado como primeira escolha, sendo um tratamento definitivo, seguro e de fácil administração. Há autores que preferem doses mais altas para induzir deliberadamente o hipotireoidismo, enquanto outros recomendam doses mais baixas que, a curto prazo, implicam menor incidência de hipotireoidismo e maior de eutireoidismo. Não há consenso sobre o melhor esquema de doses fixas a ser utilizado, sendo esse o principal enfoque deste estudo, no qual comparamos doses de 10 e 15 mCi. Dos 164 pacientes analisados, 61 (37,2%) foram submetidos a 10 mCi e 103 (62,8%), a 15 mCi de 131I. Na análise longitudinal, observou-se que a remissão do hipertireoidismo foi estatisticamente diferente no sexto mês (p < 0,001), sendo maior no grupo em que foi empregada a dose de 15 mCi. Contudo, foi semelhante nos dois grupos após 12 e 24 meses. É possível concluir que doses fixas de 10 e 15 mCi promovem semelhante remissão do hipertireoidismo após 12 meses de tratamento. A remissão do hipertireoidismo não teve associação com idade, sexo ou uso prévio de drogas antitireoidianas.

Two-day thionamide withdrawal prior to radioiodine uptake sufficiently increases uptake and does not exacerbate hyperthyroidism compared to 7-day withdrawal in Graves' disease

The appropriate period of antithyroid drug (ATD) discontinuation before radioiodine therapy is the most critical problem in Graves' disease patients under going treatment with ATD. To determine the optimal period that does not alter the outcome of radioiodine therapy or exacerbate hyperthyroidism, we compared serum FT4 levels at radioiodine uptake (RAIU) and therapy outcomes between a 2-day withdrawal group and 7-day withdrawal group. We prospectively recruited 43 patients for the 2-day withdrawal protocol and retrospectively reviewed 49 patients treated with radioiodine following the protocol of 7-day withdrawal. There was no significant difference in RAIU between the 2 groups. The mean serum FT4 level measured on the first day of 24-h RAIU of the 7-day group was significantly higher than that in the 2-day group. There were no significant differences in the outcomes at each point (6 months, 1 year, and 2 years after therapy) between the 2 groups. Our results indicated that withdrawal of ATD for 2 days is superior to 7 days in that 2 days discontinuation did not exacerbate hyperthyroidism. In order to prevent serum thyroid hormone increase after ATD withdrawal and radioiodine therapy, a 2-day ATD withdrawal period before radioiodine therapy may be useful for high-risk patients such as the elderly and patients with cardiac complications. We believe that the 2-day ATD withdrawal method may be useful for patients undergoing treatment with ATD who are to undergo radioiodine therapy.

Optimized radioiodine therapy for Graves?? disease: Two MIRD-based models for the computation of patient-specific therapeutic 131I activity

AIM

(131)I therapy is increasingly used for Graves' hyperthyroidism. Debate remains about the best method for calculating the activity to administer, as well as about the potential benefit of such computed activity. Several arguments plead, nevertheless, in favour of a personalized computation, such as inter-individual variations of thyroid volume and biokinetics.

METHODS

A MIRD-based dosimetric approach, with an additional extension that takes into account the variation of thyroid mass during the treatment, has been developed. This approach includes the benefits of a personalized determination of biokinetics. Results were compared with those of six methods widely used in routine practice. Forty-one patients were enrolled (34 women, seven men; mean age +/-SD: 48.11 +/- 6.4 years). (131)I uptakes were measured at 4, 24 and 96 h (36.2 +/- 14.6%, 42.8 +/- 9.7% and 27.6 +/- 6.8%, respectively), following administration of the tracer. The kinetics of iodine in the thyroid were evaluated using a two-compartment model (effective half-life of 5.1 +/- 1.6 days). Computations of activities to deliver the doses prescribed by the physician were done with the eight formalisms.

RESULTS

There was no statistical difference between results of the two MIRD-based formalisms (227 +/- 148 MBq and 213 +/- 124 MBq), which were also not significantly different from those obtained with the majority of the other methods (from 128 +/- 95 MBq to 275 +/- 223 MBq). However, a large intra-individual difference up to a factor of 2 between two given methods was found.

CONCLUSION

The formalism developed appears to be a good compromise between all the common formalisms already used in many institutions. Furthermore, it allows the exposures of target volumes and non-target volumes to be planned individually and practical individual radiation protection recommendations to be implemented.

The surgical management of Graves' disease

BACKGROUND

The historical aspects of the pathophysiology and treatment of Graves' disease are briefly discussed in this paper.

MATERIALS AND METHODS

The three treatment modalities of Graves' disease are anti-thyroid drug therapy, radioactive iodine therapy, and surgery. Although the majority of patients with Graves' disease in the U.S. are treated with radioactive iodine, surgery still plays an important role when patients cannot tolerate anti-thyroid drug therapy, when medical treatment is rejected by patients, or when surgery is deemed the fastest and safest route in managing the patient.

CONCLUSIONS

The indications for surgical management of Graves' disease are discussed with emphasis on available data supporting the extent of thyroid resection based on the incidences of hypothyroidism, recurrence of hyperthyroidism, recurrent laryngeal nerve injury and hypoparathyroidism.

Sensitive thyrotropin and thyrotropin-receptor antibody determinations one month after discontinuation of antithyroid drug treatment as predictors of relapse in Graves' disease

OBJECTIVE

After primary successful antithyroid drug treatment (ATDT), Graves' disease has a relapse rate of 30% to 50%. Previous studies have evaluated age, gender, goiter volume, smoking habits, and the presence of thyrotropin-receptor antibodies (TRAb) as predictive markers to facilitate an individualized patient management. Despite higher sensitivity and specificity of the new second generation human TSH-receptor assay, the predictive value of TRAb for relapse of hyperthyroidism is still controversial. In a recent prospective multicenter study we have previously shown that suppressed or low TSH values predict both early (persistence) and late relapse of Graves' disease. We now present a more detailed analysis of the predictive value of TSH and TRAb for recurrent hyperthyroidism.

METHODS

Four weeks after withdrawal of ATDT, 96 patients were available for thyroid function tests, including a sensitive third-generation TSH assay and a second-generation recombinant TSH receptor assay. Relapse of Graves' disease was evaluated for a total follow-up of 2 years.

RESULTS

Within 2 years, 47 of 96 patients (49%) developed relapse of hyperthyroidism. Nine patients relapsed within the first 4 weeks after withdrawal of ATDT and were thus considered to have persistent Graves' disease. Ten of 15 other patients with TSH levels below 0.3 mU/L without overt hyperthyroidism relapsed within 2 years. Twenty-five of 65 patients with normal TSH (0.3-3.0 mU/L) and 3 of 4 patients with TSH values above 3 mU/L also had recurrent hyperthyroidism. After ATDT cessation, TSH had a positive predictive value of 70% and a negative predictive value of 62% (specificity 85%) for relapse of Graves 'disease. Mean TRAb levels in the group of patients with relapse were significantly higher (11.1 IU/L +/- 0.17) than TRAb values in the remission group (4.5 IU/L +/- 0.6), p < 0.001. Using a cutoff value of 1.5 IU/L, TRAb had low positive and negative predictive values of 49% and 54%, respectively (specificity, 14%), but with a cutoff level of 10 IU/L, predictive values improved to 83% and 62%, respectively (specificity, 92%). Combination of TSH and TRAb determinations did not further improve prediction of relapse. Other factors such as gender, age, goiter volume, smoking habits, presence of thyroid-associated ophthalmopathy, and urinary iodine excretion did not show a significant influence on relapse rate.

CONCLUSION

Low TSH values 4 weeks after ATDT withdrawal predict relapse of Graves' disease, both early (persistence) and, to a lesser extend, within 2 years of follow-up. Also, TRAb above 10 IU/L found in a small subset of patients, correlated with a higher relapse rate.

Antithyroid drug regimen for treating Graves' hyperthyroidism

BACKGROUND

Antithyroid drugs are widely used in the therapy of hyperthyroidism. There are wide variations in the dose, regimen or duration of treatment used by health professionals.

OBJECTIVES

To assess the effects of dose, regimen and duration of antithyroid drug therapy for Graves' hyperthyroidism.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Central), MEDLINE, EMBASE, BIOSIS, CINAHL, HEALTHSTAR, Current Controlled Trials and reference lists. We contacted investigators and hand searched conference abstracts. Most recent search: July 2004.

SELECTION CRITERIA

Randomised and quasi-randomised trials of antithyroid medication for Graves' hyperthyroidism were used.

DATA COLLECTION AND ANALYSIS

Trial allocation to included, excluded and awaiting assessment categories was made by consensus. Two reviewers independently extracted data and assessed trial quality. Pooling of data for primary outcomes, and select exploratory analyses were undertaken.

MAIN RESULTS

Twenty-three randomised trials involving 3115 participants were included. Overall the quality of trials as reported was poor; specifically in terms of allocation concealment, assessor blinding and loss to follow-up. Four trials examined the effect of duration of therapy on relapse rates of Graves' hyperthyroidism. In one trial using the Titration regimen, longer duration therapy (18 months) had significantly fewer relapses (37% versus 58%) than six month therapy (Odds ratio (OR) 0.42, 95% confidence interval (CI) 0.18 to 0.96). In one quasi-randomised trial using the Block-Replace regimen, there was no significant difference between the six and 12 month (relapses rates 41% versus 35%) arms of the study. Extending the duration of therapy to over 18 months was not associated with improved relapse rates (Peto OR 0.75, 95% CI 0.39 to 1.43). Twelve trials examined the effect of Block-Replace versus Titration regimen. The relapse rates were similar in both groups at 51% in the Block-Replace group and 54% in the Titration group (Peto OR 0.86, 95% CI 0.68 to 1.08). Participants reporting rashes (10% versus 5%) and withdrawing due to side effects (16% versus 9%) were significantly higher in the Block-Replace group compared to the Titration group respectively. Three studies considered the addition of thyroxine with continued low dose antithyroid therapy after initial therapy with antithyroid drugs. There was significant heterogeneity between the studies and the difference between the two groups were not significant (Odds ratio 0.58, 95% CI 0.05 to 6.21). Four studies considered the addition of thyroxine alone after initial therapy with antithyroid drugs. There was no significant difference in the relapse rates between the groups after 12 months follow-up with relapse rates being 31% (88/282) with thyroxine and 29% (82/284) with placebo (Peto OR 1.15, 95% CI 0.79 to 1.67).

AUTHORS' CONCLUSIONS

The evidence (based on four studies) suggests that the optimal duration of antithyroid drug therapy for the Titration regimen is 12 to 18 months. The six month Block-Replace regimen was found to be as effective as the 12 month treatment in one quasi-randomised study. The Titration (low dose) regimen had fewer adverse effects than the Block-Replace (high dose) regimen and was no less effective in trials (based on 12 trials) of equal duration. Continued thyroxine treatment following initial antithyroid therapy does not appear to provide any benefit in terms of recurrence of hyperthyroidism. The incidence of hypothyroidism was not reported and there were no deaths reported in the study populations.

Advantages and disadvantages of surgical therapy and optimal extent of thyroidectomy for the treatment of hyperthyroidism

Surgery is excellent therapy for hyperthyroidism, with no mortality,and few complications or recurrences. It achieves euthyroidism rapidly and consistently, avoids long-term risks of radioactive iodine and antithyroid medications, provides tissue for histology,renders childbearing immediately possible, and allows absolute titration of thyroid hormone. Advancements such as preoperative preparation and intraoperative parathyroid hormone monitoring have decreased risks greatly and improved outcomes. Hartley-Dunhill procedure is the treatment of choice. Patients should be rendered euthyroid before operation to decrease thyroid vascularity, to improve surgical planes, and to prevent life threatening thyroid storm. Patients must be monitored carefully for hypocalcemia, a potentially serious complication. Patients will require lifelong thyroid hormone replacement. Radioactive iodine ablation should be considered for disease recurrence after surgery.

Surgical Treatment of Thyroid Cancers With Concurrent Graves Disease

BACKGROUND

Thyroid cancers with concurrent Graves disease are relatively rare. Accordingly, the natural history and optimal surgical treatment of thyroid cancers with Graves disease are controversial.

METHODS

Sixty-one thyroid cancers with concurrent Graves disease were retrospectively reviewed. Histopathologic diagnoses included 58 papillary thyroid carcinomas (95.1%), 1 follicular carcinoma (1.6%), 1 medullary carcinoma (1.6%), and 1 Hürthle cell carcinoma (1.6%).

RESULTS

The sample included 54 females and seven males. Subjects' ages ranged from 20 to 73 years (mean +/- SD, 35.9 +/- 10.6 years; median, 37 years). Average tumor size was 10.7 +/- 15.9 mm (range, 1-70 mm). Forty-nine tumors (80.3%) were 10 mm or smaller. Surgical procedures included subtotal thyroidectomy (40 patients), total thyroidectomy (16 patients), total thyroidectomy plus neck dissection (2 patients), near-total thyroidectomy (1 patient), and lobectomy with contralateral subtotal lobectomy (1 patient). Thirty-seven patients (60.7%) underwent postoperative 131I ablation for thyroid remnant. Neck lymph node metastases occurred in three patients and lung metastases in two patients. Patients who developed metastases were younger and had significantly larger tumors and higher pretreatment serum T3 level than those who did not develop metastases. No deaths occurred during the 6.2 +/- 4.1 year follow-up period (range, 1 year and 2 months to 18 years and 11 months).

CONCLUSIONS

Most thyroid cancers with concurrent Graves disease were 10 mm or smaller. Subtotal thyroidectomy is adequate for patients with Graves disease with concurrent carcinoma 10 mm or smaller.

Use of an artificial neural network to predict Graves' disease outcome within 2 years of drug withdrawal

BACKGROUND

Graves' disease (GD) is an autoimmune disorder characterized by hyperthyroidism, which can relapse in many patients after antithyroid drug treatment withdrawal. Several studies have been performed to predict the clinical course of GD in patients treated with antithyroid drugs, without conclusive results. The aim of this study was to define a set of easily achievable variables able to predict, as early as possible, the clinical outcome of GD after antithyroid therapy.

METHODS

We studied 71 patients with GD treated with methimazole for 18 months: 27 of them achieved stable remission for at least 2 years after methimazole therapy withdrawal, whereas 44 patients relapsed. We used for the first time a perceptron-like artificial neural network (ANN) approach to predict remission or relapse after methimazole withdrawal. Twenty-seven variables obtained at diagnosis or during treatment were considered.

RESULTS

Among different combinations, we identified an optimal set of seven variables available at the time of diagnosis, whose combination was useful to efficiently predict the outcome of the disease following therapy withdrawal in approximately 80% of cases. This set consists of the following variables: heart rate, presence of thyroid bruits, psycological symptoms requiring psychotropic drugs, serum TGAb and fT4 levels at presentation, thyroid-ultrasonography findings and cigarette smoking.

CONCLUSIONS

This study reveals that perceptron-like ANN is potentially a useful approach for GD-management in choosing the most appropriate therapy schedule at the time of diagnosis.

17. Immunologic endocrine disorders

Immune-mediated tissue destruction or disregulation is the cause of multiple common, as well as rare, endocrine disorders including type 1 diabetes, Graves' disease, Hashimoto thyroiditis, and Addison's disease. Each of these disorders can be divided into a series of stages beginning with genetic susceptibility, environmental triggering events, and active autoimmunity, followed by metabolic abnormalities with overt disease. Common genetic susceptibility is suggested by the clustering of a series of disorders in the same individual and his or her family. A major portion of the genetic susceptibility lies in the HLA region, but for several disorders, mutation of transcription factors underlies disease susceptibility (eg, X-linked polyendocrinopathy, immune deficiency and diarrhea, and autoimmune polyendocrine syndrome type 1). With improving immunogenetic and pathogenic understanding, type 1A diabetes is now predictable, and excellent autoantibody screening assays are available. This knowledge, combined with studies in animal models, has led to trials for the prevention of diabetes. In addition, aberrant immunologic reactions (eg, insulin autoantibodies after insulin therapy, Graves' disease after monoclonal anti-T-cell therapy in multiple sclerosis) can complicate standard and experimental therapies. We therefore believe that an understanding of the immunogenetics and immunopathogenesis of endocrine disorders can aid in the prevention of morbidity and mortality for these related diseases.

[Prognostic factors of thyroid function following surgical therapy in Graves-Basedow's disease]

BACKGROUND

The goals of this work are to describe late thyroid function and to determine predictive factors of permanent hypothyroidism following surgery in Graves-Basedow's disease.

PATIENTS AND METHOD

From 1979 to 1999, 107 patients with hyperthyroidism due to Graves-Basedow's disease underwent subtotal thyroidectomy. We performed life-table analysis and calculated the cumulative incidence of hypothyroidism by means of the Kaplan-Meier's method. Survival (euthyroidism)within patients groups was compared using the Mantel-Cox method. Variables influencing long-term thyroid function were determined by estimating the Odds ratio with a logistic regression model.

RESULTS

The probability of euthyroidism among all 107 patients at 240 months was 51.4%.Age, gender, duration of both hyperthyroidism and antithyroid therapy and weight of resected thyroid tissue did not influence the eventual outcome. The weight of thyroid remnant was 5.4 (1.5)g and the conditional logistic regression analysis showed that weight of thyroid remnant was the only variable influencing long-term thyroid function. Hyperthyroidism relapsed in 5 patients.

CONCLUSIONS

In our experience,surgery represents a definitive alternative treatment with a risk of hypothyroidism within the first 2 years of 43.9%. The weight of thyroid remnant is the only variable influencing long-term thyroid function.

Management of Graves' disease in Australia

BACKGROUND

Surveys of physicians in Europe, the USA and elsewhere have shown marked international differences in the management of Graves' disease. There are no comparable data on clinical practice in Australia.

AIMS

To examine the current management of Graves' disease by Australian endocrinologists, particularly controversial aspects of management.

METHODS

A questionnaire, modified from previous studies, was sent to members of the Endocrine Society of Australia, asking how they would manage a 43-year-old female with a first episode of Graves' disease. Eight variations on this index case (goitre size, age, sex, severity, recurrent disease) were then introduced. A novel ninth variation, recurrent Graves' disease accompanied by moderate ophthalmopathy, was added.

RESULTS

Responses from 130 endocrinologists who regularly managed Graves' disease in adults were analysed. For the index case, medical treatment with antithyroid drugs was recommended by 81% of respondents and radioiodine by 19%. Most respondents also recommended medical treatment for a patient aged 19 years, a patient with a large goitre, no goitre or severe hyperthyroidism. For an older patient aged 71 years, however, 57% of endocrinologists recommended radioiodine, and the remainder medical treatment. For recurrent Graves' disease after previous medical treatment, 76% of respondents recommended radioiodine, 22% medical treatment and 2% surgery. By contrast, for an identical case accompanied by moderate ophthalmopathy, 54% recommended medical treatment, 27% surgery and only 19% radioiodine.

CONCLUSIONS

Most endocrinologists in Australia recommend medical treatment for a first episode of Graves' disease. Radioiodine is used mainly in older patients and for recurrent disease. In the presence of significant ophthalmopathy, most endocrinologists avoid the use of radioiodine.

Treatment of Graves' disease: the advantages of surgery

The authors and others believe that surgery (thyroidectomy) is underused in the treatment for patients with Graves' disease. It is the most rapid and consistent method of making the patient euthyroid; it avoids the possible long-term risks of radioactive iodine; and it provides tissue for histologic examination. Children, young women, pregnant women, and patients with coexistent thyroid nodules are ideal candidates for thyroidectomy. It also is the treatment of choice for patients with Graves' ophthalmopathy. Patients should be rendered euthyroid before thyroidectomy. Although the operation is technically more difficult than operating on patients with nontoxic goiter or thyroid neoplasms because of the vascularity of the thyroid gland, this difference is small, and the complication rates are low. The authors recommend the Hartley-Dunhill operation (total thyroidectomy on one side and subtotal thyroidectomy on the other side, leaving about 4 to 5 g of thyroid tissue) for most patients and total thyroidectomy for patients with Graves' ophthalmopathy. In patients with recurrent or persistent thyroid cancer who fail to respond to surgery and radioactive iodine ablation, immunosuppressive therapy should be considered.

Trends in diagnostic and therapeutic criteria in Graves' disease in the last 10 years

A questionnaire describing a typical clinical case of Graves' disease and 10 variations on it was mailed to 70 Spanish units of endocrinology with the aim of assessing the new diagnostic and therapeutic trends for hyperthyroidism caused by Graves' disease in Spain and to compare the results obtained from previous studies carried out in Europe and Spain 10 years previously. Responses indicated that thyrotrophin (98%) and free thyroxine (88%) were the most used tests in the in vitro diagnosis of Graves' disease with a significant decrease in the use of total thyroxine, total triiodothyronine, and thyroglobulin in comparison with the surveys conducted 10 years previously in Europe and Spain. The presence of antibodies against the thyrotrophin receptor was the most frequently used immune marker in the diagnosis (78%) and the new use of antithyroperoxidase antibodies (36%) in diagnosis is noteworthy. Antithyroid drugs remain the treatment of choice (98%). Surgery was used mainly for large size goitres (33%) and radioiodine for recurrences after medical (61%) or surgical (80%) treatment. In conclusion, the responses obtained from this questionnaire provide insight into current specialist diagnostic and therapeutic practices with respect to Graves' disease and which could be of value to non-specialist units of endocrinology.