Use of thyroid ultrasound volume in calculating radioactive iodine dose in hyperthyroidism

One hundred twenty-one patients treated with 131I had a thyroid ultrasound to measure thyroid volume precisely. This volume measurement was used to determine the radioactive iodine dose. The average size (+/-SEM) of the thyroid glands measured in this manner was 39.7 cm3 +/- 1.9 cc. A significant correlation was found in the estimated size of the gland by the endocrinologists and the ultrasound volume. Of the 121 patients, 89 patients had the same 131I microcurie per gram of tissue factor to determine the radioactive iodine dose. This group of patients was further evaluated in this study. The average 131I dose (+/-SEM) given was 13.2 mCi +/- 0.5 mCi. The average time until hypothyroidism was achieved 2.85 +/- 0.14 months. Ultrasound provides a safe and precise way to determine actual thyroid size when calculating 131I doses.

Doppler ultrasonography in predicting relapse of hyperthyroidism in Graves' disease

PURPOSE

To determine whether Doppler ultrasonography could be useful in the prediction of relapse of hyperthyroidism in patients with Graves' disease.

MATERIAL AND METHODS

Forty patients with Graves' disease confirmed by laboratory tests were examined for a number of blood flow parameters in the inferior thyroid artery before and after they were subjected to proper antithyroid drug treatment. Data were retrospectively reviewed and compared with findings for a control group of 16 age-matched subjects.

RESULTS

Significantly increased blood flow parameters were observed both in patients with active hyperthyroidism before treatment and in euthyroid patients who presented a relapse shortly after withdrawal of proper antithyroid drug treatment versus normal controls. Conversely, no significant differences were observed between patients who remained in stable remission and normal controls.

CONCLUSION

Our results support the concept that Doppler ultrasonography evaluation of patients with Graves' disease may contribute to the detection of a relapsing course of hyperthyroidism.

[Serum cortisol level variations in thyroid diseases]

This work studies the thyroid disorders impact on adrenals glands by measuring total cortisol. Radioimmunoassays of thyroid hormones and cortisol were performed in 108 subjects, aged 20-52 years, with thyroid diseases. Our results show low cortisol values (80.35 nmol/L) in 4.77% of hyperthyroids, high values in 3.57% of hyperthyroids (1348.18 nmol/L) and 12.5% of hypothyroids (969.05 nmol/L). In hyperthyroidism, thyroid hormone stimulates the secretion of 11 ceto metabolites biologically inactive, unable to slow pituitary activity, inducing an increased production of endogene cortisol. Excessive catabolism can lead to the exhausting of overstimulated adrenal glands, and therefore to a decreased cortisol. In hypothyroidism, high cortisol results of increase cortisol half life and decrease of metabolic clearance. Control mechanisms often allow normal cortisol values. These alterations in functional activity of adrenal glands, seen in nearly 10% of these subjects, sometimes command a specific attitude in diagnosis and therapy.

[Percutaneous ultrasound-guided ethanol sclerotherapy of autonomous thyroid nodules]

Percutaneous ethanol injection therapy for autonomously functioning thyroid nodules has been performed in 53 patients. 36 patients suffered from hyperthyroidism, and 17 patients had subclinical hyperthyroidism. Ethanol was administered under ultrasonographic guidance in 2-6 sessions depending on the size of the nodule Local neck pain was the most often adverse effect. Transient dysphonia occurred in 3 patients. A subacute granulomatous thyroiditis-like reaction within 1 week after the last session occurred in 4 patients. During a 10-day steroid administration this reaction was stopped. After ethanol sclerotherapy reduction of thyroid nodular volume can be achieved. The reduction of the nodules was between 36 and 75% (mean 55 +/- 15%) of the pre-treatment volume at 6 week after therapy. In 27 of 36 hyperthyroid patients the FT4- and T3-levels became normal. Repeated sclerotherapy was successfull in 6 of the remaining 9 hyperthyroid patients. No relapse of hyperthyroidism was observed. The scintiscan showed a complete cure in 10 of 23 patients one year after PEI-therapy, while in 11 patients partial normalization of the scintiscan was observed. In 2 of 23 patients the scintiscan remained unchanged. Indication of ethanol sclerotherapy is not clear. The method appears an effective alternative procedure in patients with large nodules at high surgical risk. Under special circumstances (pregnancy or iodine-induced hyperthyroidism) ethanol sclerotherapy may be a practical alternative for toxic autonomously functioning thyroid nodules.

[Two-step radioiodine therapy in benign thyroid diseases during a single hospital visit--observations on 100 patients]

AIM

A two-step radioiodine therapy (RITh) is occasionally necessary in patients with benign thyroid disorders, when strong differences to the pretherapeutic radioiodine test occur. In this study, the parameters (uptake and effective half-life of I-131) of the radioiodine test are compared with those of the first and second RITh.

METHODS

100 patients were evaluated, who received a two-step RITh in our department between June 1992 and March 1994. Uptake and effective half-life of I-131 and the absorbed dose in the first and second therapy were compared with each other based on the daily measured activity of the thyroid.

RESULTS

A two-step RITh was necessary in 10% of the patients. The uptake of I-131 in the first RITh was significantly lower as compared to the test and significantly higher as compared to the second RITh. There were no significant changes between the effective half-life of I-131 in test, first and second RITh.

CONCLUSION

The importance of radioiodine test for the calculation of therapeutic doses is emphasized. The data gathered in our study concerning the diminution of uptake of I-131 in the second RITh can be useful for dose calculation.

[Results of TcTUs-optimized radioiodine therapy in multifocal and disseminated autonomy]

AIM

The presented study prospectively evaluates the efficacy of optimized radioiodine therapy in patients (pts) with multifocal (MFA) and disseminated (DISA) autonomy. The target dose was related to the total thyroid volume and was increased in moderate and nonlinear increments from 150 to 300 Gy dependent on the pretherapeutic Tc-99m pertechnetate thyroid uptake under suppression (TcTUs). Patients with focal autonomy were treated with a target dose independent of TcTUs and were used as control group.

METHODS

The data of 641 pts (518 women, 123 men) were evaluated, 466 pts with MFA or DISA and 175 pts with focal autonomy. In pts with MFA and DISA the target dose was increased in four steps: TcTUs < 3%: 150 Gy, > 3-6%: 200 Gy, > 6-12%: 250 Gy and > 12%: 300 Gy. In pts with focal autonomy a fixed target dose of 300 or 400 Gy was applied. The radioactivity to be administered was calculated using a modified Marinelli formula. The follow-up examination was performed at the earliest after four, on average after eight months. Normalization of TSH was the only criterion for successful therapy.

RESULTS

The success rate in pts with latent or manifest hyperthyroidism in focal autonomy was 91.5%, therapy was not successful in 5.1% and hypothyroidism occurred in 3.4%. The average success rate in pts with MFA and DISA was 91.5%, therapy failed in 7.5% and a very low rate of 1% with hypothyroidism was seen.

CONCLUSION

The presented optimized therapy concept with calculated, nonlinear increase of the target dose according to the TcTUs-level guaranteed even in MFA and DISA a high success rate comparable to that in focal autonomy along with a very low rate of hypothyroidism.

Left atrial systolic time interval in hyperthyroidism

The author noninvasively examined effects of thyroid hormone on left atrial function by using the left atrial systolic time intervals (LASTI) with its parameters as left atrial ejection time (LAET), left atrial preejection period (LAPEP), and LAET/LAPEP, as measured by pulsed Doppler echocardiography. The hyperthyroid (HTH) and normal control (NC) groups consisted of 21 and 25 subjects, respectively. He also considered serum triiodothyronine (T3) concentrations, age, heart rate, systolic blood pressure, left ventricular preload, afterload, contractility, diastolic function, P wave duration, PR interval, and left ventricular preejection period (LVPEP) as factors that might influence LASTI. LAET, LAET/LAPEP, and LVPEP in the HTH group were significantly shorter than in the NC group. LAET showed no significance with serum T3 concentration, but did with LVPEP in partial correlation analysis. These results demonstrated that a short LAET in the hyperthyroid state is controlled by a rapid rise in the left ventricular pressure.

Reoperative parathyroid surgery in the era of sestamibi scanning and intraoperative parathyroid hormone monitoring

HYPOTHESIS

Results of reoperative parathyroid surgery (RPS) have improved with the advent of sestamibi parathyroid subtraction scanning and intraoperative parathyroid hormone (IOPTH) monitoring.

DESIGN

Retrospective review of patient histories, preoperative localization studies, operative data, including IOPTH monitoring, and outcomes for patients undergoing recent RPS at a single institution. Follow-up was complete (mean, 20 months).

SETTING

Tertiary care referral center.

PATIENTS

All patients undergoing RPS for benign persistent or recurrent primary hyperparathyroidism during the period 1989 to 1997.

MAIN OUTCOME MEASURES

Overall cure rate and operative morbidity from RPS; sensitivity and accuracy of preoperative localization studies; and prediction of cure from IOPTH monitoring.

RESULTS

The study group included 124 patients (87 women and 37 men). Hypercalcemia was corrected in 109 patients (88%). Permanent recurrent laryngeal nerve injury occurred in 0.8% and permanent hypoparathyroidism in 13% of patients. Test sensitivities and accuracies, respectively, were as follows: ultrasound with biopsy, 90% and 82%; sestamibi parathyroid subtraction scanning, 82% and 67%; and ultrasound alone, 75% and 65%. Level of IOPTH was predictive of cure in all patients with a 70% or greater fall from baseline at 20 minutes after excision. Persistent multigland disease was the major cause for reoperative failure (73%).

CONCLUSIONS

Neither cure rates nor operative morbidity have changed appreciably over the past 2 decades, despite the introduction of sestamibi parathyroid subtraction scanning and IOPTH monitoring. Multigland disease continues to represent the principal cause of failure in RPS despite the routine use of preoperative localization studies. Thus far, increasing the stringency of IOPTH monitoring from a 50% to 70% decline from baseline levels has been predictive of cure, even in multigland disease. Most missed abnormal glands reside in normal anatomic locations, and the need for multiple operations, not just the reoperation, results in the increased morbidity seen with RPS.

Percutaneous ethanol injection in treatment of benign nonfunctional and hyperfunctional thyroid nodules

In recent years a new method of treatment of thyroid disorders, percutaneous ethanol injection (PEI), has been successfully used as an alternative to surgery for the management of benign nodules. In this study 103 females and 5 males (34.4 +/- 11.3 yrs) with nonfunctional cystic (23) or solid (38) nodules, and also 47 with hyperfunctional solid nodules, were treated with single or repeated ethanol injections. In all patients, the cytological studies, ultrasound evaluation and the levels of free triiodothyronine (fT3), free thyroxine (fT4), and thyrotropin or thyroids-stimulating hormone (TSH) before and after ethanol administration, were determined. The patients were followed up for 12-36 months. The size of the benign nonfunctional nodules was totally reduced in 49.9% of cases with solid and in 60.9% of patients with cystic nodules. Hyperthyroidism was cured in 91.5% of patients. The PEI procedure was connected with a few significant complications only, in relation to the localization of nodules. It was cheap, possible on an outpatient basis, easy to perform and acceptable to patients. Since the cost of thyroidectomy is high and the complication rate significant, PEI is a suitable substitute treatment especially for some patients with small toxic benign nodules of the thyroid gland.

Hyperthyroidism due to papillary carcinoma of the thyroid--a case report

A rare case of papillary carcinoma of the thyroid producing hyperthyroidism is presented. A young patients presented seven years after a thyroid operation with metastatic disease in the cervical lymph nodes and a history of deteriorating vision in the left eye. He also had a lesion in the base of the skull which could not be established to be metastasis from the thyroid cancer. There was clinical and biochemical evidence of hyperthyroidism. Radionuclide scan revealed uptake in the residual thyroid tissue and patchy uptake by the cervical lymph nodes. The patient underwent a complete thyroidectomy and radical neck dissection of the left side and 'berry-picking' of the lymph nodes on the right side. Although the patient became euthyroid post-operatively, his general condition deteriorated and he rapidly lost vision in both eyes before any ablative therapy could be instituted for the tumour in the base of the skull. The patient was lost to follow-up.

Electrocardiographic and radiographic changes in cats with hyperthyroidism: comparison of populations evaluated during 1992-1993 vs. 1979-1982

Cardiovascular manifestations of feline hyperthyroidism were compared in two populations of cats diagnosed at The Animal Medical Center from 1992 to 1993 (n=202) and 1979 to 1982 (n = 131). The prevalence of sinus tachycardia and increased R-wave voltage in lead II were both lower in the 1993 population compared with the 1982 population (p less than 0.001). A low frequency of atrial and ventricular arrhythmias and intraventricular conduction abnormalities were recorded in both populations. No significant differences between populations were recorded in the number of cats with mild, moderate, and severe cardiomegaly seen on thoracic radiographs. The percentage of cats in which radiographs were deemed clinically necessary based upon history and clinical examination was 25% of the 1993 population, compared with 63% of the 1982 population. The number of cats with radiographic evidence of congestive heart failure was 8% in 1993 compared with 20% in 1982, although this difference was not statistically significant. In conclusion, the incidence and severity of certain thyrotoxic cardiovascular manifestations were reduced in cats diagnosed between 1992 and 1993 compared with those diagnosed between 1979 and 1982.

Scintigraphic evaluation of functional thyroidal autonomy

The scintigraphic evaluation of thyroidal autonomy is performed both as a quantitative and qualitative thyroid scintigraphy with 99m-Tc-pertechnetate (99m-TcO4-), using a gamma camera fitted with an on-line computer system. A strong and linear correlation between the global 99m-Tc-pertechnetate thyroid uptake (TCTU) and I-123 clearance has been recognised. Therefore TCTU-values can be used as an reliable equivalent of the iodine clearance in the evaluation of actual thyroid function. The clinical value of the TCTU in the diagnosis of thyroidal autonomy is limited because it represents iodine clearance of both normal and autonomous tissue. As a consequence scintigraphic diagnosis and quantification of autonomy can only be established if the global 99m-Tc-pertechnetate thyroid uptake under suppression (TCTUs) is determined. This method is valuable in risk stratification of spontaneous or iodine induced hyperthyroidism, in the estimation of the target volume prior to radioiodine therapy and in the evaluation of therapeutic success after definitive therapy.

Body weight and body composition changes after treatment of hyperthyroidism

Body composition changes in nine adults with hyperthyroidism were determined with dual energy x-ray absorptiometry and computed tomography at diagnosis and after 3 and 12 months of euthyroidism achieved by surgery, antithyroid drugs, or treatment with radioiodine. Mean body weight was 67.6 kg at diagnosis and increased 2.7 kg (P=0.06) and 8.7 kg (P < 0.001) after 3 and 12 months of euthyroidism, respectively. Basal metabolic rate decreased from 2087 Cal/24 h at diagnosis to 1601 Cal/24 h at 12 months (P=0.001), whereas reported energy intake dropped from 3244 to 2436 Cal/24 h (P=0.01). According to dual energy x-ray absorptiometry, body fat was unchanged at 3 months, but increased by 5.3 kg (P < 0.0001) at 12 months. Fat-free mass increased 2.7 kg (P=0.003) at 3 months and 3.5 kg (P < 0.0001) at 12 months. Changes in bone mineral content and density did not reach significance. According to computed tomography, skeletal muscle plus skin areas increased by 11% (trunk) and 18% (thigh) at 3 months and by 17% (trunk) and 25% (thigh) at 12 months. There was no increase in sc adipose tissue (AT) at 3 months, but at 12 months this AT depot increased by 15% (thigh) and 33% (trunk). Intraperitoneal AT showed a borderline significant increase by 28% (P=0.08) at 3 months and by 40% (P=0.015) at 12 months. Areas of visceral organs and bone tissue of femur did not change significantly during the study. It is concluded that during early recovery from hyperthyroidism, priority is given to the replenishment of skeletal muscles and ip AT, whereas sc AT is increased at a later stage.

[Hyperthyroidism and cancer of the thyroid]

STUDY AIM

The idea that thyrotoxicosis is insurance against thyroid cancer has prevailed for a long time. However this association has been reported frequently in the recent literature. The aim of this study is to report our experience concerning this association and to discuss its incidence and its consequences in the light of the present data.

PATIENTS AND METHOD

Among the 734 patients who underwent a thyroidectomy between January 1983 and January 1998, there were 125 patients with hyperthyroidism, ten with associated cancer (8%). All patients were female (mean age: 43.8 years) with Graves' disease (n = 2), a toxic adenoma (n = 5), or a multi nodular toxic goiter (n = 3). The cancer was recognized intraoperatively in eight patients. A total thyroidectomy was performed in five cases and a total lobectomy associated with a subtotal contralateral lobectomy in five cases, completed by a treatment with l131 in nine cases.

RESULTS

Concurrent carcinoma was present in 10% of the patients with toxic nodular goiter and in 4.4% in those with Graves' disease. Papillary carcinoma presented in all cases. The size of the cancer was between 0.2 and 1.5 cm. Nodal involvement was present in one patient. With a follow-up of 1 to 15 years, there was no local recurrence and no metastasis.

CONCLUSION

The diagnosis of hyperthyroidism does not preclude concurrent thyroid carcinoma. The prognostic and therapeutic consequences of this association are still debated.

[First results of radioiodine therapy of multifocal and disseminated thyroid gland autonomy and use of a TcTUs-adapted dose concept]

AIM

The presented study examines prospectively the efficiency of a dose concept for radioiodine therapy (RIT) adapted to the pretherapeutic 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) in patients with multifocal (MFA) and disseminated (DISA) autonomy. This concept considers the total thyroid as target volume and uses target doses from 150 Gy to 300 Gy according to the TcTUs, which is as a measure for the "autonomous volume" of the thyroid.

METHODS

The data of 75 patients (54 female, 21 male; age 71 +/- 9 years) with MFA of DISA were evaluated. RIT was performed on patients presenting with normal values for free triiodothyronine and thyroxine and endogenous suppression of the basal thyrotropin (TSH). The following target dose were used for a TcTUs of 1.5-2.5% 150 Gy, for 2.51-3.5% 200 Gy, for 3.51-4.5% 250 Gy, and for > 4.5% 300 Gy. The radiation dose to be administered was calculated using a modified Marinelli formula. The therapy was considered as successful. When the basal TSH was above 0.5 mU/l and autonomous areas had disappeared in thyroid scintigraphy or the TcTU was below 1.5%, respectively. The average follow-up period was 8 +/- 4 months.

RESULTS

The success rates average to 92%. Only in one case a subsequent subclinical hypothyroidism and in a further case an immunogenic hyperthyroidism occurred.

CONCLUSION

The presented data indicate that even patients with a marked autonomy (TcTUs > 3.5%) can thus expected to be cured by of a one time therapy with success rate of over 90% using the presented dose concept. The rate of early hypothyroidism can altogether be estimated as very low.

Imaging the thyroid

Thyroid imaging has historically relied heavily on scintigraphy, although, not surprisingly in view of the superficial position of the gland, ultrasound has assumed an increasingly prominent role in recent years. The other cross-sectional imaging modalities can also be useful, and the emergence of new radiopharmaceuticals and the increasingly central role of fine needle aspiration cytology have further added to the range of diagnostic techniques available. This review attempts to summarize the current state of knowledge, and makes some suggestions for the most efficient use of imaging resources in the investigation of thyroid disease.

Hyperthyroidism due to lymphoma involving the thyroid gland in a patient with acquired immunodeficiency syndrome: case report and review of the literature

A 31-year old woman with acquired immunodeficiency syndrome (AIDS) and a history of lymphoma presented with a 2-week history of severe hyperthyroid symptoms and new-onset neck swelling. On physical examination, she was found to be clinically hyperthyroid, with a markedly enlarged, diffuse, tender goiter. Thyroid function testing confirmed hyperthyroidism. The patient had a rapidly deteriorating clinical course and died within days of her presentation. At autopsy, near-complete replacement of the thyroid gland with anaplastic large cell lymphoma was found, without coexisting infectious or autoimmune processes in the gland. This is the first case report of a patient with AIDS developing symptomatic thyroid involvement by lymphoma, and one of only a few case reports of hyperthyroidism associated with lymphoma in general.

Iohexol: effects on uptake of radioactive iodine in the thyroid and on thyroid function

RATIONALE AND OBJECTIVES

The authors attempted to determine whether the use of nonionic contrast media causes uptake of iodine by the thyroid to be blocked and whether use of these agents could cause iodine-induced hyperthyroidism.

MATERIALS AND METHODS

Twenty-eight persons, including 22 with thyroid disease, were included in the study. Subjects underwent computed tomography (CT) of the thyroid after injection of 100 mL of iohexol. Thyroid function variables were measured before CT scanning and 1 week and 1 month later. In 16 subjects, uptake of iodine-131 by the thyroid was measured before and 1 week after CT.

RESULTS

I-131 uptake was reduced to 53.4% at 1 week after the injection of iohexol but became normal within a few weeks (followed up in one patient). An accelerated escape of I-131 from the thyroid was seen during the 1st days after the iohexol administration. Eight of 22 patients with an underlying thyroid disease had a temporary change in thyroid function. In four patients, the serum thyrotropin level was increased 1 week after the iohexol administration. In four other patients, temporary hyperthyroidism developed during the following months.

CONCLUSION

Iohexol can be used in patients with an underlying thyroid disease, but close monitoring in the following months is necessary.

[Echocardiographic parameters in hyperthyroidism with and without cardiothyreosis]

There has been little research done on the differences between hyperthyroidie patients who exhibit cardiothyrosis and those who do not. The objective of this research was to elucidate the variations in echocardiographic parameters that exist between these two groups, in order to determine practical implications. A prospective study on 37 subjects was performed: 20 in group I (without cardiothyreosis) and 17 in group II (exhibiting cardiothyreosis). In both groups, women were predominant. Left ventricular diameters and volumes were statistically higher in group II (p < 0.0007). The left ventricular end systölic stress was also higher (140.10(3) +/- 37 vs 131.10(3) +/- 51 dynes/cm2. p < 0.05). There was no significance between the two groups in shortening fraction, ejection fraction and mean rate of circumferential fiber shortening. The E/A ratio of the mitral flow was higher in group II (1.98 +/- 1.3 vs 1.3 +/- 0.7, p < 0.05), but the isovolumetric relaxation time and the deceleration time of the E wave were similar in both groups. Left ventricular systolic dysfunction was observed in 5 patients of each group. Relaxation abnormalities were found in 10% of the subjects in group 1 and 33.3% in group II. Significant valvular regurgitation was observed only in group II (8 cases of mitral, 1 case of tricuspid and I case of aortic regurgitation). Given that cardiovascular perturbations may be different during the stages of the hyperthyroidism, different therapeutic approaches may thus be considered, facilated by appropriate echocardiographic examination.

[Suppressibility of thyroid autonomy in endogenous and additional exogenous TSH suppression in patients with thyroid autonomy]

AIM

The aim of this retrospective study was to examine the effect of an additional exogenous thyroid hormone suppression on the 99m Technetium Thyroid-Uptake (TcTU) in patients with thyroid autonomy and endogenous TSH suppression.

METHODS

21 patients were examined in the years 1992-1996; they had a primary endogenous suppression (end) of the TSH-b and an evaluation of the TcTU. After an additional exogenous suppression (ex) of the thyroid, the first two weeks with 75 micrograms/dl and the following 2 weeks 150 micrograms/d, or depending on the bodyweight 2 micrograms/kg levothyroxin, another evaluation of the TcTU was performed. The whole patients were called group I with a TcTUend of 1.6%-7.4%. The subgroups were selected by thresholds of the TcTUend; group Ia TcTUend > or = 1.6% and < 2.5%, group lb TcTUend > or = 2.5%, group Ic TcTUend > or = 3%.

RESULTS

The intraindividual comparison showed a significant decrease of the autonomous "volume" after exogenous suppression with levothyroxin. This is shown by the following values of the TcTU: group I TcTUend = 3.47 +/- 1.65 and TcTUex = 2.91 +/- 1.38, which means a reduction of 20 rel.% (p < or = 0.001); group Ia TcTUend = 2.05 +/- 0.27, TcTUex = 1.85% +/- 0.22, which means 10 rel.% (p < or = 0.001); group Ib TcTUend = 4.18 +/- 1.59, TcTUex = 3.45% +/- 1.34, which means 20 rel.% (p < or = 0.001); group Ic TcTUend = 5.00% +/- 1.43, TcTUex = 4.05% +/- 1.32, which means 20 rel.% (p < or = 0.001).

CONCLUSION

Supposing a structural variability of autonomous thyroid tissue with heterogenous TSH receptors our study shows a significant additional exogenous suppression in already endogenous suppressed TSH receptors.