Changes in Thyrotropin Receptor Antibody Levels Following Total Thyroidectomy or Radioiodine Therapy in Patients with Refractory Graves' Disease.

Background: The actions of thyrotropin-binding inhibitory immunoglobulins (TBIIs) against thyrotropin receptors in thyroid follicular cells have been studied as important etiological factors in Graves' disease (GD). The purpose of this study was to investigate changes in the TBII levels of patients undergoing total thyroidectomy (TTx) or radioactive iodine (RAI) therapy for GD refractory to antithyroid drugs (ATDs). Methods: We enrolled patients who underwent TTx or RAI for GD with previous ATD use between January 2011 and December 2017 at the Samsung Medical Center in Seoul, Korea. Thorough retrospective reviews of medical records were performed in 130 patients. Results: Patients with goiter, ophthalmopathy, high levels of TBIIs, and high doses of ATDs received TTx. Elderly patients with arrhythmia received RAI. We observed that TBII levels continued to decrease after TTx. On the contrary, TBIIs initially increased for 138 days (estimated median time) and then decreased slowly after RAI. A faster decline in TBII levels was observed in the TTx group than in the RAI group (p < 0.001). The estimated median time for TBIIs to decrease below 4.5 IU (3 × upper normal limit, which is known to be a risk factor for fetal hyperthyroidism) was 318 days in the TTx group and 659 days in the RAI group, respectively. In the RAI group, high levels of TBII (>4.5 IU/L) were present in 70 (82%) at 6 months, 57 (67%) at 1 year, and 3 (3%) at 2 years. In the TTx group, rapid decreases in TBII levels were observed in younger patients and those with lower baseline TBII levels. In the RAI group, smaller thyroid volume was correlated with more rapid decrease in TBII levels. Conclusions: The changes in TBII levels following TTx or RAI were different in patients with refractory GD. When deciding on TTx or RAI, this difference should be considered with patient age, severity of hyperthyroidism, goiter, ophthalmopathy, and future pregnancy plans (for young female patients).

Correction for hyperfunctioning radiation-induced stunning (CHRIS) in benign thyroid diseases.

PURPOSE: Radioiodine-131 treatment has been a well-established therapy for benign thyroid diseases for more than 75 years. However, the physiological reasons of the so-called stunning phenomenon, defined as a reduced radioiodine uptake after previous diagnostic radioiodine administration, are still discussed controversially. In a recent study, a significant dependence of thyroid stunning on the pre-therapeutically administered radiation dose could be demonstrated in patients with goiter and multifocal autonomous nodules. A release of thyroid hormones to the blood due to radiation-induced destruction of thyroid follicles leading to a temporarily reduced cell metabolism was postulated as possible reason for this indication-specific stunning effect. Therefore, the aim of this study was to develop dose-dependent correction factors to account for stunning and thereby improve precision of radioiodine treatment in these indications. METHODS: A retrospective analysis of 313 patients (135 with goiter and 178 with multifocal autonomous nodules), who underwent radioiodine uptake testing and radioiodine treatment, was performed. The previously determined indication-specific values for stunning of 8.2% per Gray in patients with multifocal autonomous nodules and 21% per Gray in patients with goiter were used to modify the Marinelli equation by the calculation of correction factors for hyperfunctioning radiation-induced stunning (CHRIS). Subsequently, the calculation of the required activity of radioiodine-131 to obtain an intra-therapeutic target dose of 150 Gy was re-evaluated in all patients. Furthermore, a calculation of the hypothetically received target dose by using the CHRIS-calculated values was performed and compared with the received target doses. RESULTS: After integrating the previously obtained results for stunning, CHRIS-modified Marinelli equations could be developed for goiter and multifocal autonomous nodules. For patients with goiter, the mean value of administered doses calculated with CHRIS was 149 Gy and did not differ from the calculation with the conventional Marinelli equation of 152 Gy with statistical significance (p = 0.60). However, the statistical comparison revealed a highly significant improvement (p < 0.000001) of the fluctuation range of the results received with CHRIS. Similar results were obtained in the subgroup of patients with multifocal autonomous nodules. The mean value of the administered dose calculated with the conventional Marinelli equation was 131 Gy and therefore significantly below the CHRIS-calculated radiation dose of 150 Gy (p < 0.05). Again, the fluctuation range of the CHRIS-calculated radiation dose in the target volume was significantly improved compared with the conventional Marinelli equation (p < 0.000001). CONCLUSIONS: With the presented CHRIS equation it is possible to calculate a required individual stunning-independent radioiodine activity for the first time by only using data from the radioiodine uptake testing. The results of this study deepen our understanding of thyroid stunning in benign thyroid diseases and improve precision of dosimetry in radioiodine-131 therapy of goiter and multifocal autonomous nodules.

The success rate of radioactive iodine therapy for Graves' disease in iodine-replete area and affecting factors: a single-center study.

OBJECTIVE: Initial treatment options for Graves' disease include antithyroid drugs, radioactive iodine (RAI), and surgery. Because of similar effects of three modalities, initial treatment preferences differ by country to country. In Korea, iodine-replete area, RAI was used as a second-line option. For these reasons, the RAI success rate in Korea might differ from other countries. METHODS: A total of 247 patients were enrolled. The primary outcome was cumulative success rate in the first year, and the secondary outcome was factors that affected the success. Delayed response, which included patients who attained successful RAI during the follow-up, after the first year without further RAI, and factors that affected the delayed response were reviewed. RESULTS: The cumulative success rate in the first year was 62.8%. Higher RAI activity [odds ratio (OR) 2.56, P = 0.02], longer disease duration (OR 0.43, P = 0.01), larger goiter (OR 0.31, P = 0.01), and higher post-RAI fT4 (fT4 between upper normal limit (UNL) to 1.5 × UNL; OR 0.24; P < 0.01, 1.5 × UNL<; OR 0.08; P < 0.01) were associated with RAI success. Twenty-seven patients showed delayed response, and goiter size (P < 0.05), pre-RAI TSH receptor Ab (TRAb) level (P < 0.01) and post-RAI fT4 (P < 0.01) were associated. CONCLUSION: The success rate of the first RAI in Korea was lower than that in other countries. Delayed response was observed in patients with smaller goiter, low pre-RAI TRAb, and low post-RAI fT4. In these patients, clinical follow-up with monitoring could be an option, and decision of optimal timing of first RAI is crucial.

Radioiodine Therapy Does Not Change the Atherosclerotic Burden of the Carotid Arteries.

BACKGROUND AND AIM: Atherosclerosis evolves or accelerates when arteries are exposed to ionizing radiation, both early and late after exposure. Radioiodine therapy of benign thyroid disease exposes the carotid arteries to 4-50 Gy, and may thereby increase the risk of atherosclerosis. Increased risk of cerebrovascular events has been reported after radioiodine therapy. This study aimed to examine whether atherosclerosis develops early or late after radioiodine therapy of benign thyroid disease. METHOD: Patients treated for benign thyroid disorders (nontoxic goiter, adenoma, and hyperthyroidism) were examined with ultrasound for the main outcome, carotid intima media thickness (CIMT), and for plaque presence (plaque presence only in late damage). Signs of early damage from radioiodine were studied in 39 radioiodine-treated patients, who were examined before treatment and at 1, 3, 6, and 12 months after treatment. Late changes were studied in a cross-sectional case-control design, with radioiodine-treated patients as cases (n = 193) and patients treated with surgery as controls (n = 95). Data were analyzed with repeated measurement for longitudinal data, and with multivariate regression for cross-sectional data. Results were adjusted for age, sex, cholesterol, smoking status, known atherosclerotic disease, and body mass index. RESULTS: No changes in CIMT were found in the patients followed prospectively for one year after treatment with radioactive iodine for benign thyroid disease (p = 0.58). In the study on late effects, there was no difference in CIMT (p = 0.25) or presence of plaques (p = 0.70) between those treated with radioactive iodine and those treated with surgery (9.8 and 5.6 years since treatment, respectively). Furthermore, the level of thyrotropin (TSH) did not influence these atherosclerosis markers. CONCLUSION: No early changes in CIMT were detected in patients treated with radioactive iodine for benign thyroid disease. No signs of late effects of radioactive iodine on CIMT or plaque presence were found after 10 years of follow-up. The radiation to the carotid arteries by radioactive iodine therapy for benign thyroid disease may therefore have no or low effect on atherosclerotic burden of the carotid arteries in general.

The thyroid-related quality of life measure ThyPRO has good responsiveness and ability to detect relevant treatment effects.

BACKGROUND AND PURPOSE: Patient-reported outcomes have become important endpoints in comparative effectiveness research and in patient-centered health care. Valid patient-reported outcome measures detect and respond to clinically relevant changes. The purpose of this study was to evaluate responsiveness of the thyroid-related quality of life (QoL) instrument ThyPRO in patients undergoing relevant clinical treatments for benign thyroid diseases and to compare it with responsiveness of the generic SF-36 Health Survey. METHODS: A sample of 435 patients undergoing treatment completed the ThyPRO and SF-36 Health Survey (Version 2) at baseline and 6 months after treatment initiation. Responsiveness was evaluated in three thyroid patient groups: patients with hyperthyroidism (n = 66) and hypothyroidism (n = 84) rendered euthyroid after medical therapy, and patients with a clinically detectable nontoxic goiter treated with surgery or radioactive iodine and remaining euthyroid (n = 62). Changes in QoL were evaluated in terms of effect size and compared to the changes predicted by clinical experts. The responsiveness of equivalent scales from ThyPRO and SF-36 Health Survey were compared with the relative validity index. RESULTS: The ThyPRO demonstrated good responsiveness across the whole range of QoL aspects in patients with hyper- and hypothyroidism. Responsiveness to treatment of nontoxic goiter was also demonstrated for physical and mental symptoms and overall QoL, but not for impact on social life or cosmetic complaints, in contrast to clinicians' predictions. For all comparable scales except one, the ThyPRO was more responsive to treatment than the SF-36 Health Survey. CONCLUSIONS: The ThyPRO was responsive to treatment across the range of benign thyroid diseases. We suggest implementing this measurement instrument as a patient-reported outcome in clinical studies and in clinical management.

Parathyroid gland function after radioiodine ((131)I) therapy for toxic and non-toxic goitre.

INTRODUCTION: The therapeutic effect of radioactive iodine ((131)I) on benign goitre consists of the emission of tissue-destructive beta-radiation. Since the range of beta (131)I radiation in tissue can reach 2.4 mm, it can affect the adjacent parathyroid glands. The purpose of this paper is to assess parathyroid function in patients with toxic and non-toxic goitres, up to five years following (131)I therapy. MATERIAL AND METHODS: The study sample consisted of 325 patients with benign goitres (220 with toxic nodular goitre (TNG), 25 with non-toxic nodular goitre (NTNG), and 80 with Graves' disease (GD) treated with (131)I. The therapeutic activity of (131)I for each patient was calculated using Marinelli's formula. The serum levels of fT3, fT4, TSH, iPTH and Ca(2+), Ca and phosphates were determined one week before (131)I administration, as well as every two months up to a year following the therapy, and then after three and five years post-treatment. RESULTS: After two months following the administration of (131)I, all the treated patients showed a statistically significant above normal increase in iPTH concentrations (amounting to a value almost twice the norm in patients with TNG), which remained stable up to ten months after treatment, to return to normal level in the following months. In all the patients, Ca(2+), Ca, phosphates concentration remained within normal range throughout the course of the study. The concentrations of fT3 and fT4 quickly returned to normal after (131)I administration, and remained within normal range until the completion of the study. CONCLUSION: Radioiodine treatment of benign thyroid disorders results in transient (up to ten months after (131)I administration) hyperparathyroidism. The condition does not influence the level of calcium and phosphates concentration in any significant way.

Giving radioiodine? Think about airport security alarms.

An increased sensitivity of airport detectors, a growing number of isotopic tests, and globalization of the society have raised a number of false positive radioactive alarms at airports and public places. This paper presents two new cases of patients who triggered airport security alarms after receiving 740MBq of (131)I for non-toxic goitre and attempts to compare surprisingly limited literature concerning this problem. A 57-year-old man triggered a security alarm at three different airports on the 17th, 28th, and 31st day after radioiodine exposure. Interestingly enough, in the meantime, on the 18th and 22nd day, no radiation was detected in him at the airport where he was twice detained as a source of radiation later on. The second case presents a 45-year-old woman who activated security alarm detectors while crossing a border on her coach trip 28 days after radioiodine administration.

[Peritoneal strumosis: an extension study with (99m)Tc-pertecnectate]. / Strumosis peritoneal: estudio de extensión con (99m)Tc-pertecnectato.

We report the case of a 35-year-old nulliparous woman, with a previous history of ovarian cystectomy diagnosed 3 years earlier due a struma ovarii type of monodermal teratoma in the right ovary and a hemorrhagic cyst in the left ovary. Progressive growth of the left adnexal mass was observed in the periodic medical check-ups. Due to this, a second laparoscopy was performed and, based on the findings, a left ovarian cystectomy, right salpingectomy and resection of multiple peritoneal implants were carried out. The pathology diagnosis was left struma ovarii and peritoneal strumosis. A whole body and SPECT/CT scan with (99m)Tc-pertechnetate was performed to detect possible peritoneal implants. This study helped to make the therapeutic decision.

The predictive role of 24h RAIU with respect to the outcome of low fixed dose radioiodine therapy in patients with diffuse toxic goiter.

UNLABELLED: Radioactive iodine uptake (RAIU) is a test used to differentiate hyperthyroidism from thyroiditis and to calculate the radioiodine dose for treatment of Graves' disease. We aimed to evaluate the predictive role of 24h RAIU with respect to the outcome of radioiodine therapy in patients with diffuse toxic goiter (DTG). METHODS: Case records of patients with DTG treated with radioactive iodine were reviewed retrospectively. Patients were divided into two groups based on 24h RAIU (normal range: 15% - 35% at 24 h): the first group included patients with 24h RAIU values equal to or less than 50%, while the second group included patients with 24h RAIU values of over 50%. Gland size, duration of disease, treatment with antithyroid drugs (ATD) and its duration were the other factors considered. Success of the first dose of 131I was defined as a euthyroid or hypothyroid status at 12 months post-therapy without the need for additional radioiodine or ATD therapy. Data were analyzed with 95% power and 1% type I error (α=0.01). RESULTS: Six hundred thirty-three (633) consecutive patients with DTG were given a fixed-dose (5mCi) of radioiodine between January 1987 and December 2006. One hundred seventy-five patients (175) had an RAIU ≤50% and 458 patients had an RAIU >50%. First-dose success rate in the former group was 81.7% and in the second group 68.6% (p=0.001). The overall first-dose success was 72%. Multivariate analysis confirmed the significant role of 24h RAIU data to predict a successful outcome. CONCLUSION: A 24h RAIU value of ≤50% appears to be associated with a significantly better outcome compared to that of a 24h RAIU value of >50% in patients with DTG given as treatment a fixed dose of 185 MBq radioiodine.

Treatment of autonomously functioning thyroid nodules at a single institution: radioiodine therapy, surgery, and ethanol injection therapy.

OBJECTIVE: The purpose of this study was to clarify the efficacy of radioiodine (RI) therapy in Japanese patients with autonomously functioning thyroid nodules (AFTNs). METHODS: We performed a retrospective analysis to assess the management of AFTN patients. Thyroid lobectomy was performed to treat toxic adenoma (TA) patients, and total thyroidectomy to treat toxic multinodular goiter (TMNG) patients. RI therapy was administered in the form of a single dose (500 MBq) of isotope in the outpatient clinic. Percutaneous ethanol injection therapy (PEIT) was performed under ultrasound guidance. RESULTS: Of the total 205 patients, consisting of 159 TA and 46 TMNG patients, 99 underwent surgery, 50 received RI therapy, and 56 received PEIT. Remission of thyrotoxicosis was achieved in all of the patients who were treated surgically. Hypothyroidism was documented in six of the 72 patients who were treated surgically other than by total thyroidectomy. Remission of thyrotoxicosis was observed in 43 of the 50 patients who were treated by RI therapy. Nine TA patients developed hypothyroidism during the follow-up period after RI therapy. Several PEIT sessions were required to achieve a remission of thyrotoxicosis. Remission of thyrotoxicosis was achieved in 29 of the 56 patients treated by PEIT, and thyrotoxicosis recurred in 17 these 56 patients. CONCLUSION: Surgery is the treatment of choice for large nodules and nodules that are resistant to other treatments, because it allows prompt control of thyrotoxicosis. RI therapy is a safe and effective means of controlling thyrotoxicosis in AFTN patients. We conclude that RI therapy is the treatment of choice for definitive treatment of AFTN patients who do not have local compression symptoms.

Follow-up on thyroidal uptake after radioiodine therapy: how robust is the peri-therapeutic dosimetry?

Radioiodine therapy (RIT) for benign thyroid diseases in Germany requires the patient to stay in a nuclear medicine therapy ward for at least 48 hours and the dose to the thyroid to be computed from activity measurements performed during that stay. A major part of the total dose will be delivered after the patient's discharge from the hospital and thus has to be predicted through extrapolation with the effective half-life measured peri-therapeutically. We performed repeated thyroid uptake measurements on patients up to five months post therapy to investigate post-therapeutic changes in their effective half-lives and examine the dosimetric consequences. 12 patients (4 m, 8 f; age 36 - 76 y; 4 Graves' disease, 4 toxic adenoma, 3 toxic goitre, 1 non-toxic goitre) underwent late uptake measurements (1 - 7 meas., 13 - 154 d post administration, median 54 d, performed with thyroid probe resp. whole body counter at lower activities). Doses calculated from late measurements were compared to those predicted at discharge; half-lives calculated from the late measurement closest to the median delay (54 d) were compared to those determined at time of discharge. A cross-calibration between activity calibrator, thyroid probe, and whole body counter over an activity range from 52 MBq down to 45 Bq revealed linearity to within 6%, which was considered sufficient. In 9 out of 12 patients the achieved dose was within the range predicted at discharge. Averaged deviation between achieved and predicted dose was 3.1±2.2% (median 2.5%, range 0.7% - 7.2%). Averaged deviation between post- and peri-therapeutic half-lives was 5.1±3.9% (median 3.5%, range 1.3% - 12.5%). For n=5 patients discharged after 3 days, averaged deviations were greater (dose 4.0%, half-life 5.6%) than for those patients (n=7) who stayed in the hospital for a minimum of 4 days (dose 2.5%, half-life 4.8%). Excretion of iodine from the thyroid remains practically unchanged for at least two months after RIT. The dosimetric procedure implemented in our institution warrants a robust prediction of the post-therapeutic half-life and thus the actual achieved dose.

Current safety practices relating to I-131 administration for diseases of the thyroid: a survey of physicians and allied practitioners.

BACKGROUND: There is little information about the individual safety instructions provided by healthcare professionals to patients receiving radioactive iodine (I-131) therapy for the treatment of benign and malignant thyroid disorders or about whether these instructions are consistent across medical specialties. Currently, no national guidelines exist to standardize safety instructions related to I-131 administration. Here, we examine the spectrum of I-131 safety practices in contemporary use. METHODS: Members of major societies of physicians and allied specialists who treat patients with thyroid disorders were invited to complete a 27-question online survey about safety practices related to I-131 administration. Data from questionnaires were analyzed by type of safety recommendation and grouped according to provider specialty and geographic location. RESULTS: A total of 311 endocrinologists, surgeons, nuclear medicine radiologists, and allied health professionals completed questionnaires. They indicated that patients often receive instruction from more than one treating specialist. The decision to hospitalize a patient for treatment and the length of stay were determined by the patient's social situation and the dose of I-131 administered. Starting at I-131 doses between 259 and 1073 MBq (7 and 29 mCi), over 60% of respondents advised avoiding contact with children, sexual activity, and breastfeeding, with the latter recommendation continuing beyond 48 hours after treatment. Personal hygiene, laundry, and meal preparation precautions varied across respondents. Over 90% of respondents used serum or urine testing to screen for pregnancy status. Precautions to delay parenthood were given more often to female than male patients (90% vs. 60%), with a minimum recommended delay of 6 months. About 20% of respondents considered insurance coverage as a factor in selecting outpatient versus inpatient I-131 therapy, and this consideration varied geographically. CONCLUSION: A wide variety of safety recommendations are given to patients who receive I-131. To our knowledge, this survey represents the first organized inquiry into safety practices related to I-131 administration. The diversity of responses suggests an opportunity for multispecialty collaboration in defining more uniform recommendations for patient safety instructions during and after I-131 treatment.

Radioactive iodine 1311 (RAI) treatment. The nearest to the "magic bullet" but should always be preceded by a risk assessment, especially in the pediatric patient.

Radioactive iodine treatment is very frequently the best approach, but it should be optimized by dosimetric and risk considerations.

Radioiodine therapy of benign thyroid disorders: what are the effective thyroidal half-life and uptake of 131I?

AIM: The use of radioiodine therapy is common in the treatment of benign thyroid disease. Council directive Euratom 97/43 requires that for all medical exposure of individuals for radiotherapeutic purposes exposures of target volumes should be individually planned. There are several strategies to accomplish this aim for radioiodine therapy including individual radioiodine uptake measurement and using either individual or mean effective radioiodine uptake and half-life. Although it is always simple to use standard activities, the effective thyroidal half-life and thyroidal uptake of I needs to be estimated individually to achieve optimal dosimetric results. We analyzed the radioiodine half-life and uptake in a large number of patients for use in a semi-individual calculation. METHODS: Patients presenting consecutively between 1 January 2006 and 31 December 2007 were included in the study. Inclusion criteria were the control of hyperthyroidism and withdrawal of antithyroid drugs 2 days before preliminary radioiodine testing and therapy. Patients were treated for Graves' disease (n=363), nontoxic goitre (n=50), toxic goitre (n=639), or toxic uninodular adenoma (n=365). The effective half-life and uptake of I were estimated by uptake measurements after 24 h and 5 days during the preliminary radioiodine test, and serial measurements over 5 days during therapy. RESULTS: The mean effective half-life of I measured during radioiodine therapy was 5.4 days in Graves' disease, 6.4 days in nontoxic goitre, 6.6 days in toxic goitre, and 5.7 days in toxic uninodular adenoma. The mean maximal uptake of I measured during radioiodine therapy was 64% in Graves' disease, 42% in nontoxic goitre, 38% in toxic goitre, and 31% in toxic uninodular adenoma. CONCLUSION: These actual values analyzed here might be used for a semi-individual calculation of therapeutic activity when an individual approach is not possible.

[Selective pituitary resistance to thyroid hormone in a patient treated with amiodarone]. / Resistencia hipofisaria a las hormonas tiroideas en un paciente tratado con amiodarona.

Selective pituitary resistance to thyroid hormones is a syndrome that involves inadequate response of thyroid-stimulating hormone to changes in thyroid hormones. Unlike generalized resistance syndromes, this entity produces central hyperthyroidism and clinical thyrotoxicosis. Sometimes the disease may not be properly diagnosed and is treated with drugs with harmful effects on the thyroid, such as amiodarone, hampering diagnosis and possibly exacerbating the disorder. The treatment of this condition can be symptomatic, based on control of tachycardia and anxiety, or etiological, acting on the pituitary to regulate thyrotropin secretion or on the thyroid gland to control thyroid hormone production. We report the case of a patient with pituitary resistance to thyroid hormone, who was treated with amiodarone to control paroxysmal atrial fibrillation.

Radioiodine therapy in patients with amiodarone-induced thyrotoxicosis (AIT).

INTRODUCTION: Amiodarone (AM) is frequently used in the therapy of patients with cardiac disorders. However, due to high iodine content, it has side effects on thyroid function. The use of radioiodine therapy (RIT) in amiodarone-induced thyrotoxicosis (AIT) with low radioactive iodine uptake (RAIU) is still controversial. In these patients therapeutic choices for refractory disease include surgery, antithyroid drugs, or glu ocorticosteriods. AIM: The aim of the study was to evaluate the efficacy of RIT in patients presenting AIT and low RAIU in two-year follow-up. PATIENTS AND METHODS: 40 patients (25 men and 15 women) aged from 63 to 83 years (x +/- SD: 66.2 +/- 5.0 years; median: 65 years) treated with RIT were included into the study. In these patients AM therapy was essential for the underlying heart disorder, while surgery, antithyroid drugs or glucocorticosteroids, were contraindicated. Forty seven patients with toxic multinodular goiter (TMNG) (39 women and 8 men), matched for age (67 +/- 12 yr; range 54-89 yr), were enrolled into the study as a comparative group. The diagnostic procedures included baseline thyroid function tests (thyrothropin - TSH, free triiodothyronine - fT3 and free thyroxine - fT4 levels), thyroid autoantibodies measurement (antithyroglobulin autoantibodies - TgAb, antithyroid peroxidase autoantibodies - TPOAb, anti-TSH receptor autoantibodies - TRAb), thyroid ultrasonography, thyroid scintiscan and RAIU assessment. RESULTS: Serum values of TSH, TgAb, TPOAb and TRAb were undetectable in both groups. In patients with AIT fT4 level was 18.7 to 38.7 pmol/l (mean: 27.1 +/- 5.8) and fT3 concentration was 3.9 to 5.6 pmo/l (mean: 5.7 +/- 1.4), while in TMNG patients level of fT4 was 31.5 to 22.2 pmol/l (mean: 25,3 +/- 5,8) and fT3 concentration was 3.8 to 4,2 pmo/l (mean: 4,2 +/- 0,2). Mean RAIU values after 5h and 24h in AIT patients were 2.3 +/- 0.5 and 3.1 +/- 0.9%, while in TMNG patients were 18,0 +/- 3,8 and 35,7 +/- 9,1%, respectively. A significant difference (p<0.001) between 5h and 24h RAIU in AIT compared to TMNG was noted. In all patients with AIT, a dose of 800 MBq of 131I was administered. During two-year-observation recurrence of hyperthyroidism was observed in two patients (5%) with TMNG. These patients received a second radioiodine dose 16.2 +/- 15 months later (the mean re-treatment dose was 735.93 +/- 196.1 MBq). In comparison, none of the patients with AIT required a second 131I dose and only one patient (2.5%) 6 months after ablative 131I dose needed anti-thyroid medication. Transient hypothyroidism was observed in only two patients (5%) with AIH, though was not observed in TMNG. During follow-up time, no sudden deaths in AIT patients were observed; one patient was diagnosed with prostate cancer, and in one patient acute toxic hepatitis after AM occurred. CONCLUSION: RIT may be a safe and useful method of AIT therapy in patients with low RAIU, in whom other treatment methods are contraindicated.

Optimizing 131I uptake after rhTSH stimulation in patients with nontoxic multinodular goiter: evidence from a prospective, randomized, double-blind study.

UNLABELLED: Prestimulation with recombinant human thyroid-stimulating hormone (rhTSH) augments radioiodine (131)I therapy for benign nontoxic multinodular goiter. The purpose of this study was to determine the optimal time interval between rhTSH and (131)I administration to enhance thyroid radioactive iodine uptake (RAIU). METHODS: Patients were randomized, in a 2-factorial design, to receive either a 0.1-mg dose of rhTSH (n = 60) or placebo (n = 30) and to a time interval of 24, 48, or 72 h before (131)I administration. The rhTSH- or placebo-stimulated RAIU study was performed at 4 wk after a baseline RAIU assessment in a tertiary referral center at a university hospital. A total of 90 patients (78 women; median age, 52 y; range, 22-83 y) referred to (131)I therapy for symptomatic nontoxic goiter (median goiter volume, 63 mL; range, 25-464 mL) were included in the study. Change in thyroid RAIU was determined at 24 and 96 h after (131)I tracer administration. RESULTS: In the placebo subgroups, RAIU did not change significantly from baseline. The mean (+/-SE) 24-h RAIU increased from 33.8% +/- 2.3% to 66.0% +/- 1.8% (111.2% increase) with a 24-h interval, from 36.8% +/- 2.1% to 64.6% +/- 2.7% (83.3% increase) with a 48-h interval, and from 33.0% +/- 2.7% to 49.6% +/- 2.5% (62.4% increase) with a 72-h interval. All within-group changes were highly significant (P < 0.001). The effect was negatively correlated with initial RAIU (r = -0.703, P < 0.001). The increase in 24- and 96-h RAIU was significantly higher in the rhTSH/24-h group than it was in the rhTSH/72-h group (P = 0.023 and 0.012, respectively) and insignificantly higher than in the rhTSH/48-h group (P = 0.37 and 0.26, respectively). CONCLUSION: The effect of rhTSH on thyroid RAIU is most pronounced when administered 24 h before (131)I administration and declines with longer time intervals. Whether there is a similar time dependency for goiter reduction after rhTSH-stimulated (131)I-therapy remains to be clarified.

Radioiodine therapy for thyroid volume reduction of large goitres.

OBJECTIVE: To evaluate the effect of radioiodine therapy for volume reduction in large goitres. METHODS: A retrospective study was performed involving 88 patients treated between 2001 and 2007 with radioiodine for toxic or nontoxic goitres. The goitres were between 80 and 250 ml in volume (median 127 ml+/-38.57). Activities of I to be administered were calculated individually through radioiodine testing with uptake measurements over 5 days, the mean activity being 1721+/-440 MBq I (714-2395 MBq I), equivalent to a mean of 14+/-4.19 MBq I/g of thyroid tissue (6-24 MBq I/g of thyroid tissue). The designated dose was 150 Gy for the entire thyroid volume, and post-therapeutic dosimetry revealed a mean thyroid dose of 175+/-45.92 Gy (64-300 Gy). Control examinations were performed, including thyroid blood testing and thyroid ultrasound at 6 weeks and at 3, 6, 12, 24, 36, 48 and 72 months after radioiodine therapy. RESULTS: The mean volume reduction was 41.9% after 3 months and 65.9% after 1 year. Thyroid volume reduction was highly significant (P<0.001) in the first year after radioiodine therapy. No volume increase was observed in any patient during follow-up. Unfortunately, many patients were lost during follow-up (n = 84 after 3 months, n = 38 after 1 year). CONCLUSION: Radioiodine therapy is an effective treatment for both nontoxic and toxic goitres, resulting in a highly significant thyroid volume reduction of nearly 66% within 1 year.

Therapy of large multinodular goitre using repeated doses of radioiodine.

OBJECTIVE: To evaluate the efficacy of radioiodine therapy using I in a group of patients with large multinodular goitre (LMG). METHODS: The study was carried out in patients with goitre volume greater than 100 cm and in patients with LMG who were disqualified from surgery. The study included 34 female participants (age range: 62-84 years) with LMG: 26 patients were hyperthyroid and eight patients had a nontoxic goitre. The patients were treated with 800 MBq of radioiodine administered four times at 3-month intervals (total activity of 3.2 GBq). Before each therapy course, serum thyrotropin, free thyroxin, free triiodothyronine and antithyroid antibodies were measured, ultrasonography and thyroid scan were performed. Patients were followed up for a minimum of 24 months. Fine-needle biopsy was done before qualification to the study. RESULTS: Before therapy, median thyroid volume was 145 cm. It decreased during therapy to 65-76 cm after 12 months and to 50-62 cm after 24 months. After 24 months, 60% of patients were euthyroid and 40% of patients were hypothyroid. During therapy, significant increases in TSHRAb, TPOAb and TgAb levels were observed. No correlation between the levels of antithyroid antibodies, radioiodine uptake, reduction of goitre volume and hormonal status was found. CONCLUSION: In most cases of LMG, repeated administration of radioiodine is safe and effective. The highest response of the thyroid volume is observed after the first course of treatment. On account of a high incidence of hypothyroidism, the patients should be monitored during and after therapy.

Prediction of cure and risk of hypothyroidism in patients receiving 131I for hyperthyroidism.

CONTEXT: There is little consensus regarding the most appropriate dose of radioiodine ((131)I) to be administered to patients with hyperthyroidism. OBJECTIVE: To compare the efficacy of fixed dose regimens of (131)I in curing hyperthyroidism and to define simple clinical and biochemical factors that predict outcome in individual patients. DESIGN: Consecutive series of hyperthyroid subjects treated with (131)I. SETTING: Single Secondary/Tertiary Care Hospital Clinic. PARTICIPANTS: A total of 1278 patients (1013 females and 262 males, mean age 49.7 years) presenting with hyperthyroidism between 1984 and 2006. INTERVENTION: Treatment with (131)I using a fixed dose regimen. MAIN OUTCOME MEASURES: Probability of cure and risk of development of hypothyroidism following a single dose of (131)I. RESULTS: Patients given a single dose of (131)I of 600 MBq (n = 485) had a higher cure rate (84.1%) compared with those receiving either 370 MBq (74.9%, P < 0.001) or those given 185 Bq (63%, P < 0.001). An increased incidence of hypothyroidism by 1 year was evident with higher doses (600 MBq: 60.4%; 370 MBq: 49.2%, P = 0.001; 185 Bq: 38.1%, P < 0.001). Binary logistic regression analysis identified a 600 Bq dose of (131)I [adjusted odds ratio, AOR 3.33 (2.28-4.85), P < 0.001], female gender [AOR 1.75 (1.23-2.47), P = 0.002], lower presenting serum free T4 concentration [AOR 1.01 (1.01-1.02), P < 0.001] and absence of a palpable goitre [AOR 3.33 (2.00-5.56), P < 0.001] to be independent predictors of cure. Similarly, a 600 MBq dose [AOR 3.79 (2.66-5.38), P < 0.001], female gender [AOR 1.46 (1.05-2.02), P = 0.02], younger age [AOR 1.03 (1.02-1.04), P < 0.001], absence of a palpable goitre [AOR 3.85 (2.38-5.88), P < 0.001] and presence of ophthalmopathy [AOR 1.57 (1.06-2.31), P = 0.02] were identified as independent factors predicting the probability of development of hypothyroidism at one year. Based on these findings, formulae to indicate probability of cure and risk of hypothyroidism for application to individual patients were derived. CONCLUSIONS: Simple clinical/biochemical criteria can be used to predict outcome after (131)I treatment. These factors determine that males, those with severe biochemical hyperthyroidism, and those with a palpable goitre require larger doses (600 MBq) in order to achieve cure.