Single Dose Of Radioiodine Research Articles

Long-Term Follow-up of Patients With Autonomous Thyroid Nodules Treated With Radioiodine.

This article aims to describe the presentation of Plummer disease and its evolution after radioiodine treatment and determine factors that may influence treatment efficacy. The sample included retrospective medical records of 165 adult patients with toxic nodular goiter treated with radioiodine between 1997 and 2017, followed up at a single thyroid center. The efficacy of treatment with a single dose of radioiodine was higher than 90%. The mean radioiodine activity was 28.9 ± 3.4 mCi. The mean time between radioiodine performance and hyperthyroidism resolution was 3.6 ± 3.0 months, ranging from 1-12 months. After the first year, 33.9% of the patients were under hypothyroidism, 59.4% under euthyroidism, and 6.7% under hyperthyroidism. Among the nonresponders, the variables that showed statistical difference were the presence of multinodular goiter and the radioiodine activity (mean, 25.5 ± 6.5 mCi; median, 30 [15-30 mCi]). The cumulative rate of hypothyroidism was 48.9% over 20 years of follow-up. Radioiodine therapy is an effective and safe treatment. In Plummer disease, high rates of euthyroidism are expected after the radioiodine treatment. Therapeutic failure was observed mainly in patients with larger multinodular goiters treated with lower doses of radioiodine. The evolution to hypothyroidism was mostly observed in younger patients with larger and uninodular goiters.

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

Multinodular goitre is common in women. Treatments for non-toxic multinodular goitre include surgery, levothyroxine suppressive therapy, and radioiodine. Radioiodine therapy is the only non-surgical alternative for non-toxic multinodular goitre. However, a high amount of radioiodine is needed to enable the thyroid nodules to adequately take up the radioiodine, because the multinodular goitre takes up a low amount of iodine. Recombinant human thyrotropin (rhTSH) has been used to increase radioiodine uptake and reduce thyroid volume of the multinodular goitre. Whether the improved reduction of the goitre resulting from rhTSH-stimulated radioiodine therapy is beneficial to the person remains controversial. To assess the effects of recombinant human thyrotropin-aided radioiodine treatment for non-toxic multinodular goitre. We searched the CENTRAL, MEDLINE, Scopus as well as ICTRP Search Portal and ClinicalTrials.gov. The date of the last search of all databases was 18 December 2020. We included randomised controlled clinical trials (RCTs) comparing the effects of rhTSH-aided radioiodine treatment compared with radioiodine alone for non-toxic multinodular goitre, with at least 12 months of follow-up. Two review authors independently screened titles and abstracts for relevance. Screening for inclusion, data extraction, and risk of bias assessment were carried out by one review author and checked by a second. Our main outcomes were health-related quality of life (QoL), hypothyroidism, adverse events, thyroid volume, all-cause mortality, and costs. We used a random-effects model to perform meta-analyses, and calculated risk ratios (RRs) for dichotomous outcomes, and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We evaluated the certainty of the evidence using the GRADE approach. We included six RCTs. A total of 197 participants were allocated torhTSh-aided radioiodine therapy, and 124 participants were allocated to radioiodine. A single dose of radioiodine was administered 24 hours after the intramuscular injection of a single dose of rhTSH. The duration of follow-up ranged between 12 and 36 months. Low-certainty evidence from one study, with 85 participants, showed uncertain effects for QoL for either intervention. RhTSH-aided radioiodine increased hypothyroidism compared with radioiodine alone (64/197 participants (32.5%) in the rhTSH-aided radioiodine group versus 15/124 participants (12.1%) in the radioiodine alone group; RR 2.53, 95% CI 1.52 to 4.20; 6 studies, 321 participants; moderate-certainty evidence in favour of radioiodine alone). A total of 118/197 participants (59.9%) in the rhTSH-aided radioiodine group compared with 60/124 participants (48.4%) in the radioiodine alone group experienced adverse events (random-effects RR 1.24, 95% CI 0.94 to 1.63; 6 studies, 321 participants; fixed-effect RR 1.23, 95% CI 1.02 to 1.49 in favour of radioiodine only; low-certainty evidence). RhTSH-aided radioiodine reduced thyroid volume with a MD of 11.9% (95% CI 4.4to 19.4; 6 studies,268participants; moderate-certainty evidence). One study with 28 participants reported one death in the radioiodine alone group (very-low certainty evidence). No study reported on costs. RhTSH-aided radioiodine treatment for non-toxic multinodular goitre, compared to radioiodine alone, probably increased the risk of hypothyroidism but probably led to a greater reduction in thyroid volume. Data on QoL and costs were sparse or missing.

Efficacy of radioiodine in the treatment of primary hyperthyroidism

Background: Radioiodine (RI) is a commonly used treatment modality for primary hyperthyroidism. A single dose of RI has been reported to cure hyperthyroidism in the range of 50%–90% of the treated cases. The efficacy of RI treatment has not yet been investigated in the local population. Objectives: To assess the efficacy of RI therapy in patients with primary hyperthyroidism treated at Tawam Hospital, Al Ain, UAE. Patients and Methods: The electronic medical records of hyperthyroid patients who received RI treatment at Tawam Hospital between January 2009 and March 2017 were reviewed. The diagnosis was verified by reviewing clinical, laboratory, and imaging data. Following RI therapy, a cure was defined as the development of hypothyroidism or euthyroid status without the aid of antithyroid drugs (ATDs) within 6 months post-RI therapy. Multivariate analysis was used to assess predictors of RI response. Results: A total of 125 patients (68.8% women) met the study criteria. The mean age ± standard deviation (SD) at RI therapy was 40 ± 15.1 years. The etiology of hyperthyroidism was available for 121 patients; Graves' disease (GD) (n = 83, 68.6%), toxic multinodular goiter (TMNG) (n = 31, 25.6%), and toxic adenoma (TA) (n = 7, 5.8%). The majority of patients (109, 87.2%) were pretreated with ATDs; 70.3% of those were treated for a period exceeding 18 months. Almost quarter of the patients were referred to RI due to other compelling medical reasons including ATDs intolerance, neutropenia, and hepatotoxicity. The mean ± SD administered RI activity was 14.6 ± 3.7 mCi (range: 8–25). Treatment response evaluation was possible in 97 cases. Post a single dose of RI treatment, 91.8% of patients achieved either euthyroid or hypothyroid status. Patients with GD developed hypothyroidism more frequently than TMNG or TA (80.6% vs. 65.2% vs. 33.3%, respectively). The time to cure was within 3 months in 21% and 3–6 months in 79% of the patients. The given dosage of I131 was the only predictor of cure rate. No major adverse effects were reported. Conclusion: We found that there is a delay in referring potential patients with hyperthyroidism for RI treatment and the cure rate of a single dose of I131 is 91.8% within 6 months of posttreatment; patients with TA may require higher doses of I131 therapy. Further studies are needed to explore the patient–physician barriers in utilizing RI as a timely mode of treatment for appropriately selected patients.

Radioiodine therapy versus antithyroid medications for Graves' disease.

Graves' disease is the most common cause of hyperthyroidism. Both antithyroid medications and radioiodine are commonly used treatments but their frequency of use varies between regions and countries. Despite the commonness of the diagnosis, any possible differences between the two treatments with respect to long-term outcomes remain unknown. To assess the effects of radioiodine therapy versus antithyroid medications for Graves' disease. We performed a systematic literature search in the Cochrane Library, MEDLINE and EMBASE and the trials registers ICTRP Search Portal and ClinicalTrials.gov. The date of the last search was September 2015 for all databases. Randomised controlled trials (RCTs) comparing the effects of radioiodine therapy versus antithyroid medications for Graves' disease with at least two years follow-up. Two authors independently screened titles and abstracts for relevance. One author carried out screening for inclusion, data extraction and 'Risk of bias' assessment and a second author checked this. We presented data not suitable for meta-analysis as descriptive data. We analysed the overall quality of evidence utilising the GRADE instrument. We included two RCTs involving 425 adult participants with Graves' disease in this review. Altogether 204 participants were randomised to radioiodine therapy and 221 to methimazole therapy. A single dose of radioiodine was administered. The duration of methimazole medication was 18 months. The period of follow-up was at least two years, depending on the outcome measured. For most outcome measures risk of bias was low; for the outcomes health-related quality of life as well as development and worsening of Graves' ophthalmopathy risks of performance bias and detection bias were high in at least one of the two RCTs.Health-related quality of life appeared to be similar in the radioiodine and methimazole treatment groups, however no quantitative data were reported (425 participants; 2 trials; low quality evidence). The development and worsening of Graves' ophthalmopathy was observed in 76 of 202 radioiodine-treated participants (38%) and in 40 of 215 methimazole-treated participants (19%): risk ratio (RR) 1.94 (95% confidence interval (CI) 1.40 to 2.70); 417 participants; 2 trials; low quality evidence. A total of 35% to 56% of radioiodine-treated participants and 42% of participants treated with methimazole were smokers, which is associated with the risk of worsening or development of Graves' ophthalmopathy. Euthyroidism was not achieved by any participant being treated with radioiodine compared with 64/68 (94%) of participants after methimazole treatment (112 participants; 1 trial). In this trial thyroxine therapy was not introduced early in both treatment arms to avoid hypothyroidism. Recurrence of hyperthyroidism (relapse) in favour of radioiodine treatment showed a RR of 0.20 (95% CI 0.01 to 2.66); P value = 0.22; 417 participants; 2 trials; very low quality evidence. Heterogeneity was high (I² = 91%) and the RRs were 0.61 or 0.06 with non-overlapping CIs. Adverse events other than development of worsening of Graves' ophthalmopathy for radioiodine therapy were hypothyroidism (39 of 41 participants (95%) compared with 0% of participants receiving methimazole, however thyroxine treatment to avoid hypothyroidism was not introduced early in the radioiodine group - 104 participants; 1 trial; very low quality evidence) and drug-related adverse events for methimazole treatment (23 of 215 participants (11%) reported adverse effects likely related to methimazole therapy - 215 participants; 2 trials; very low quality evidence). The outcome measures all-cause mortality and bone mineral density were not reported in the included trials. One trial (174 participants) reported socioeconomic effects: costs based on the official hospital reimbursement system in Sweden for patients without relapse and methimazole treatment were USD 1126/1164 (young/older methimazole group) and for radioiodine treatment USD 1862. Costs for patients with relapse and methimazole treatment were USD 2284/1972 (young/older methimazole group) and for radioiodine treatment USD 2760. The only antithyroid drug investigated in the two included trials was methimazole, which might limit the applicability of our findings with regard to other compounds such as propylthiouracil. Results from two RCTs suggest that radioiodine treatment is associated with an increased risk of Graves' ophthalmopathy. Our findings suggest some benefit from radioiodine treatment for recurrence of hyperthyroidism (relapse) but there is uncertainty about the magnitude of the effect size.

Clinical Efficacy of A Single Dose Radioiodine Therapy for Hyperthyroidism

<p><strong>Objective</strong>: Radioiodine is a safe, cheap, and recognized permanent treatment option for patients with hyperthyroidism. Despite, the extensive use of radioiodine therapy in hyperthyroidism there is no consensus regarding the optimal dose of radioiodine. To evaluate the clinical efficacy and our clinical experience with the use of a single dose radioiodine therapy for hyperthyroidism in our institution.</p><p><strong>Methods:</strong> A total of 274 patients who received a single dose of radioactive iodine therapy for hyperthyroidism at our institution between 2007-2015 were retrospectively reviewed. Of these, 186 patients had Graves’ disease (GD), 73 patients had Plummer’s disease (PD), and 15 patients had a single toxic adenoma (STA). All patients received between 10-30mCi of oral radioiodine capsule. The efficacy of therapy was determined 3 months post-therapy using serum thyroid function test, weight and heart rate measurements. Therapy success refers to patients whose outcome was euthyroidism and hypothyroidism post-therapy and treatment failure where patients still manifested with persistent hyperthyroidism.</p><p><strong>Results:</strong> The efficacy of a single dose of radioiodine 3months post-therapy varies with the type of hyperthyroidism, 96% for Graves’s disease, 92% for Plummer’s disease and 100% in single toxic adenoma.</p><p><strong>Conclusion:</strong> Our study showed that a single dose of radioactive iodine therapy 3 months post-therapy is 96% efficient in all types of hyperthyroidism. However, we observed that patients at risk of therapy failure 3month post-therapy included, large thyroid gland prolong antithyroid drug usage and male gender.</p><p> </p>

Influence of prior carbimazole on the outcome of radioiodine therapy in pediatric and adolescent Graves' disease.

Therapeutic options for pediatric Graves' disease (PGD) include antithyroid drug therapy (ATD) as the first line and radioiodine (I-131) therapy as the second line of treatment. To date, controversies persist regarding the true effect of prior ATD in the outcome of I-131 therapy in PGD. This study evaluated the effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD. This is a retrospective study covering the years 1995-2012, with a median follow-up of 75 months. Records of 114 children (84 girls and 30 boys, age range: 5-20 years, mean 24-h radioiodine uptake, 58%) who had clinically and biochemically proven Graves' disease irrespective of prior ATD therapy were included. All patients were treated with fixed doses of 5 mCi (185 MBq) I-131 for Graves' disease; 74 had undergone prior carbimazole treatment (group 1) and 40 were drug naive (group 2). The endpoint of follow-up was stable euthyroid or hypothyroid in patients. The effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD patients was evaluated. The success of radioiodine therapy was defined as the cure of hyperthyroidism. Variables were analyzed to identify the potential predictive factors for euthyroidism/hypothyroidism after treatment. The cure rate was 70% in group 1 and 83% in group 2 with a single dose of radioiodine (P=0.299). The success rate achieved at the end of 1-year follow-up in group 1 and group 2 was 81 and 87%, respectively (P=0.401). No independent predictor was associated with success or failure of treatment. At the median follow-up of 75 months (range: 12-216 months), 76% of patients were hypothyroid on replacement doses of levothyroxine and 24% still continued to be euthyroid. Prior carbimazole treatment does not alter the outcome of radioiodine therapy in PGD.

Prognostic Value ofTc99m-Pertechnetate Thyroid Scintigraphy in Radioiodine Therapy in a Cohort of Chinese Graves’ Disease Patients: A Pilot Clinical Study

Objectives. This study is to assess the prognostic value of 99mTc-pertechnetate thyroid scintigraphy for predicting the outcomes of fixed low dose of radioiodine therapy (RIT) in a cohort of Chinese Graves' disease (GD) patients. Materials and Methods. This is a retrospective study of GD patients who received RIT with a single dose of radioiodine (5 mCi). All the patients received 99mTc-pertechnetate thyroid scintigraphy prior to RIT. Thyroid mass, 99mTc-pertechnetate uptake, gender, age at diagnosis, duration of the disease, ophthalmopathy, and serum levels of FT4, FT3, TT4, and TT3 prior to RIT were analyzed as potential interference factors for outcomes of RIT. Results. One hundred and eighteen GD patients who completed RIT were followed up for 12 months. The outcomes (euthyroidism, hypothyroidism, and hyperthyroidism) were found to be significantly associated with thyroid mass and 99mTc-pertechnetate uptake. Patients with thyroid mass ≤ 40.1 g or 99mTc-pertechnetate uptake ≤ 15.2% had higher treatment success. Conclusions. A fixed low dose of 5 mCi radioiodine seems to be practical and effective for the treatment of Chinese GD patients with thyroid mass ≤ 40.1 g and 99mTc-pertechnetate uptake ≤ 15.2%. This study demonstrates 99mTc-pertechnetate thyroid scintigraphy is an important prognostic factor for predicting the outcomes of RIT.

Outcomes of Total Thyroidectomy with Therapeutic Central and Lateral Neck Dissection with a Single Dose of Radioiodine in the Treatment of Regionally Advanced Papillary Thyroid Cancer and Effects on Serum Thyroglobulin

Achieving an undetectable serum thyroglobulin (Tg) level (<1.0 ng/mL) after surgical and radioiodine treatment for papillary thyroid cancer (PTC) is associated with low recurrence rates and has been termed biochemical remission. This study aimed to determine the effectiveness of total thyroidectomy with therapeutic central and lateral neck dissection for regionally advanced (T1-4bN1bM0) PTC with regard to posttreatment Tg levels. This is a single-institution retrospective cohort study of patients with regionally advanced PTC initially treated with total thyroidectomy and therapeutic levels 2-7 neck dissection from 2002 to 2012. Pathologic findings, complications, serum Tg levels, and outcomes were analyzed. Sixty-one patients were initially treated with total thyroidectomy and therapeutic central and lateral neck dissection for PTC involving the lateral cervical nodes (N1b). The median number of lymph nodes excised and positive was 27 (range 5-112) and 9 (range 1-67), respectively. Extranodal extension occurred in 48 %. Radioiodine was administered after surgery with a median total dose of 150 mCi (range 30-244 mCi). Recurrent or persistent cervical disease occurred in 8 (13 %) and 3 (5 %) patients, respectively, and required additional radioiodine treatment in 2 and reoperative neck dissection in 10. Three patients developed new distant metastasis, and 1 died during the median follow-up of 20 months (range 1-109 months). Undetectable unstimulated Tg (<1.0 ng/mL) without clinically detectable recurrence was experienced in 68 % of patients with initial treatment. Biochemical remission can be experienced in most patients presenting with regionally advanced PTC with total thyroidectomy and compartment based therapeutic neck dissection followed by a single dose of radioiodine.

Unfavourable effect of prolonged treatment with antithyroid drugs on radioiodine therapy outcome in Graves' hyperthyroidism

Radioiodine therapy (RIT) of Graves' hyperthyroidism (GH) is usually recommended after failure of primary therapy with antithyroid drugs (ATDs), which are commonly prescribed for up to 18-24 months. However, in our region, the prolonged ATDs treatment of the disease is very common. Thus, we assessed the efficacy of RIT after prolonged continual pretreatment with ATDs in Graves' hyperthyroidism. Therapy outcome using a single dose of radioiodine was evaluated after one year in 91 patients (f/m: 73/18, age: 50.2±10.9 yr). According to ATDs pretreatment duration, the patients were classified into: 1st group <2 yr, 2nd group 2-3 yr and 3rd group >3 yr. In relation to RIT outcome, the patients were estimated as cured (euthyroid or hypothyroid) or non-cured (hyperthyroid). Overall, after one year of follow-up, 52.7% patients were cured with one dose of radioiodine. Comparing mean values of patients' age and TSH serum levels at time of RIT as well as radioiodine dose between cured and non-cured patients of the whole population of patients, significant differences have not been observed. However, non-cured patients were significantly longer pretreated with ATDs (p<0.005). The ratio between the cured and non-cured patients was 73.9% vs. 26.1% in the first group (p<0.0001), 65.5% vs. 34.5% in the second (p <0.001) and 30.8% vs. 69.2% in the third group (p<0.0001). There was no significant difference in radioiodine dose, duration of ATDs pretreatment, TSH levels and patients' age between cured and non-cured patients in each group, although non-cured patients from the third group were somewhat older (p=0.085). Among the cured patients who were <50 or ≥50 yr of age, a significant difference was found only in the third group (a smaller percent of patients were ≥50 years old). The results of this study suggest that prolongation of ATDs pretreatment of Graves' hyperthyroidism over two years should not be allowed because of their unfavourable effect on radioiodine therapy outcome. Nevertheless, if a patient has been treated much longer, especially if he/she is ≥ 50 years of age, administration of higher doses of radioiodine may be recommended in order to achieve a better outcome.

Radioiodine therapy in Graves’ disease

To assess the predictability of outcome and evaluate the factors that may lead to treatment failure in patients with Graves' disease who are treated with a single dose of radioiodine. This is a retrospective study of 123 patients (M: 42; F: 81) with Graves' disease who received radioiodine therapy with a single fixed (10 mCi) dose for hyperthyroidism. Pretreatment age, sex, BMI, type of anti-thyroid drug used, propylthiouracil doses, iodine uptake, uptake ratio (4/24 h radioiodine uptake), and thyroid volume of the patients in whom radioiodine therapy succeeded or failed were compared. Post-therapy follow-up revealed that therapy failed in 22% of the patients. Iodine uptakes and uptake ratios and volumes were found to be significantly higher in patients in whom therapy failed. It was observed that uptake ratio was at least 1 in 25 patients (20%), and therapy failed in 20 (80%) of these patients. Of the 98 patients (80%) in whom uptake ratio was less than 1, therapy was unsuccessful in only seven (7%). Uptake ratio is a simple index that may be used to predict the patients in whom therapy may fail or succeed. In patients with Graves' disease who have an uptake ratio of less than 1, radioiodine appears to be an effective dose with high success rates. In contrast, because of the high rates of failure in patients with an uptake ratio of at least 1, use of radioiodine therapy at a dose of 10 mCi does not seem to be appropriate.

The follow-up of radioiodine-treated hyperthyroid patients: should thyroid function be monitored more frequently?

There is a lack of data regarding the timing and particularly the severity of hypothyroidism post radioiodine (RI). To investigate the timing and severity of hypothyroidism in RI-treated hyperthyroid patients. Retrospective examination of the records of 183 RI-treated hyperthyroid patients (79 autoimmune hyperthyroidism, 46 toxic multinodular goiter, and 58 hyperthyroidism of indeterminate etiology). One hundred and fifty-nine patients requiring a single dose of RI (435 MBq), 107 (67%) developed hypothyroidism. Hypothyroidism detected in: 16% of patients at <8 weeks, 46% at 8 to <16 weeks, 24% at 16 to <24 weeks, 9% at 24 to <36 weeks, 3% at 36 to <52 weeks, and 2% at >52 weeks. One hundred and eighty-three patients had follow-up after one or more doses of RI and 124 (68%) patients developed hypothyroidism; of these, 44 (36%) had TSH>50 mU/l and 34 (27%) had free T4<5 pmol/l when hypothyroidism was first detected. Of those patients with a delayed outpatient visit (no.=77) and those with an outpatient visit within the recommended target interval (no.=47), median TSH was 23 (0.05-152) mU/l and 32 (0.05-150) mU/l, respectively (p=0.75) and median free T4 was 7.1 (1.3-16.7) pmol/l and 6.6 (1.3-15.4) pmol/l, respectively (p=0.21) at first detection of hypothyroidism. The severity of hypothyroidism when first detected during follow-up is of concern and suggests that closer monitoring of thyroid function is required, particularly during the first 6 months post- RI therapy.

Radioiodine Treatment of Graves’ Disease in Young People

In Europe young patients with Graves’ disease are usually treated with antithyroid drugs initially, then if hyperthyroidism recurs after a prolonged course of such medication, they are offered definitive treatment by subtotal or total thyroidectomy. Neither of these forms of treatment is free from problems. Impressed with the simplicity and safety record of radioiodine therapy, we have treated 8 young patients with radioiodine. The patients all presented with typical Graves’ disease and relapsed after 18–24 months of treatment with antithyroid drugs. They were then given the option of a further course of antithyroid medication or definitive treatment with radioiodine or surgery. Those who opted for radioiodine were treated with ¹³¹iodine in a dose of 300 MBq with the intention of ablating the thyroid. Antithyroid medication was resumed for 4–6 months and then withdrawn. Four patients became hypothyroid after a single dose of radioiodine but 4 needed a second dose. All became hypothyroid within 2 years. No adverse effects were observed, in particular no patient showed any deterioration in their eye disease. Radioiodine offers a simple, effective and inexpensive method of treatment for Graves’ disease in young patients. There are no immediate adverse effects and, although some theoretical concerns remain, to date the long-term safety record of thyroid ablation is excellent and the potential risks seem to us to be outweighed by the advantages. Even when a moderately high initial dose of radioiodine is used, a second dose may be needed.

The effect of radioiodine and antithyroid drugs on serum long acting thyroid stimulator protector (IATS-P). A three year prospective study.

Over a three year period we have studied the effect of either a one year course of Carbimazole or a single dose of radioiodine in a group of 46 patients with Graves' disease. Initially, in untreated patients LATS-P was present in 39 (85%) but at the end of the study was only detectable in 19 (41%). The clinical outcome in 29 patients initially treated with carbimazole correlated well with changes in serum LATS-P which persisted in 18. Thirteen of these ultimately required radioiodine or sub-total thyroidectomy. With radioiodine two patterns of response were seen, in some LATS-P levels declined, whereas in others transient increases were seen usually during the first year but subsequently fell. There was no difference in clinical response between the two groups. Overall, the study indicates that serum LATS-P is related to the clinical course of Graves' disease but there remains a minority of patients in whom the activity cannot be detected.