sodium-pertechnetate-tc-99m and Hyperthyroidism

It seems somewhat difficult to exactly define the real number of case reports concerning the association of hyperfunctioning thyroid node and carcinoma; the overall incidence of this condition seems, however, to be very rare. Different inclusion criteria are probably a fairly relevant cause of variability in the number of cases reported during the years. A basic classification scheme, as the one here reported, may be of help in characterizing the different possible conditions: 1. the coexistence of carcinoma and focally hyperfunctioning tissue in the same gland but at different locations (not uncommon); 2. the presence of such a large tumour mass that it can compete with normal tissue for tracer uptake, despite being hormonogenetically uneffective in itself; 3. the carcinoma located in the hyperfunctioning adenoma; 4. the real hyperfunctioning carcinoma, where coincidence between hyperfunctioning tissue and malignancy is complete (very rare). Two cases are reported here, respectively belonging to the third and fourth of these categories (the most challenging from a diagnostic point of view). The matter is intrinsically poor from a statistical standpoint: it is therefore difficult to draw definitive conclusions on the subject in operative terms. It is however felt that the systematic evaluation of oncological risk in thyroid nodes, occasionally recommended in the literature, may be cumbersome and not necessarily cost-effective.

Topics: Adenocarcinoma, Follicular; Adenoma; Adult; Carcinoma, Papillary; Combined Modality Therapy; Diagnostic Errors; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Lung Neoplasms; Middle Aged; Neoplasms, Multiple Primary; Radionuclide Imaging; Radiotherapy, Adjuvant; Reoperation; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroid Nodule; Thyroidectomy

Topics: Aged; Female; Follow-Up Studies; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Postoperative Complications; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroidectomy

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.

Topics: Gamma Cameras; Humans; Hyperthyroidism; Iodine; Iodine Radioisotopes; Radiographic Image Interpretation, Computer-Assisted; Radionuclide Imaging; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thyroid Diseases

The diagnosis of thyroidal autonomy is based mainly on quantitative scintigraphy of the thyroid. The specificity of an echopoor pattern in ultrasound for autonomy is low. Also determination of TSH is only half as sensitive as measurement of uptake of 99mTc-pertechnetate under suppression (TcTU-supp) in diagnosing autonomy. For diagnosis and decision about therapeutical consequences of thyroidal autonomy the quantitative scintigraphy under suppression is recommended; side-effects of suppression by Levothyroxin are low.

Topics: Goiter, Endemic; Humans; Hyperthyroidism; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Hormones; Ultrasonography

Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement.. Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic.. Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3).. TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal.. ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

Topics: Adult; Antithyroid Agents; Female; Graves Disease; Humans; Hyperthyroidism; Immunoglobulins, Thyroid-Stimulating; Male; Middle Aged; Predictive Value of Tests; Prognosis; Recurrence; Reference Values; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Tomography, Emission-Computed; Treatment Outcome; Withholding Treatment

Salivary dysfunction is the most common side effect associated with (131)I therapy in patients with differentiated thyroid cancer. The purpose of this study was to evaluate the effect of parotid gland (PG) massage on radioisotope accumulation in the salivary gland.. Sixty patients were included in this study. Using Tc-99m pertechnetate, two salivary scans were performed in all patients. In 30 patients, PG massage was performed between the two salivary gland scans, whereas in the other 30 patients no massage was performed between the two scans. Total counts of both PGs and accumulation ratios were calculated.. In the patients who received massage, no difference was observed between the mean PG counts of first and second images (8556.9±3333.4 count vs. 8598.3±3341.3 count, p=0.39). In the patients who did not receive massage, the mean PG count on second images was significantly higher than that on first images (8581.2±3618.0 count vs. 9096.4±3654.0 count, p<0.01). Mean accumulation ratio in the patients who received massage was significantly lower than in the patients who did not receive massage (0.5%±3.3% vs. 6.8%±3.8%, p<0.01). Further, among the patients who received massage there was a higher percentage of patients with a negative accumulation ratio than among the patients who did not receive massage (43.3% vs. 0%, p<0.01).. PG massage can reduce Tc-99m pertechnetate accumulation in the PG, and thus, should be helpful to prevent salivary damage associated with (131)I therapy.

Topics: Adolescent; Adult; Aged; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Massage; Middle Aged; Parotid Gland; Prospective Studies; Radionuclide Imaging; Salivary Glands; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Young Adult

The aim of this study was to evaluate the feasibility of applying a previously described dose strategy based on (99m)Tc-pertechnetate thyroid uptake under thyrotropin suppression (TcTU(s)) to radioiodine therapy for unifocal thyroid autonomy.. A total of 425 consecutive patients (302 females, 123 males; age 63.1+/-10.3 years) with unifocal thyroid autonomy were treated at three different centres with (131)I, using Marinelli's formula for calculation of three different absorbed dose schedules: 100-300 Gy to the total thyroid volume according to the pre-treatment TcTU(s) (n=146), 300 Gy to the nodule volume (n=137) and 400 Gy to the nodule volume (n=142).. Successful elimination of functional thyroid autonomy with either euthyroidism or hypothyroidism occurred at a mean of 12 months after radioiodine therapy in 94.5% of patients receiving 100-300 Gy to the thyroid volume, in 89.8% of patients receiving 300 Gy to the nodule volume and in 94.4% receiving 400 Gy to the nodule volume. Reduction in thyroid volume was highest for the 100-300 Gy per thyroid and 400 Gy per nodule strategies (36+/-19% and 38+/-20%, respectively) and significantly lower for the 300 Gy per nodule strategy (28+/-16%; p<0.01).. A dose strategy based on the TcTU(s) can be used independently of the scintigraphic pattern of functional autonomous tissue in the thyroid.

Topics: Adult; Aged; Aged, 80 and over; Dose Fractionation, Radiation; Dose-Response Relationship, Radiation; Feasibility Studies; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Prognosis; Radionuclide Imaging; Radiopharmaceuticals; Radiotherapy Dosage; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Sodium Pertechnetate Tc 99m; Treatment Outcome

The aim of this study was to optimise radioiodine therapy of diffuse and nodular toxic goitre by calculation of the radiation dose delivered to the thyroid on the basis of the pretreatment technetium-99m pertechnetate thyroid uptake under thyrotropin suppression (TcTU(s)). The TcTU(s) value serves as a substitute for the non-suppressible iodine turnover and the functional autonomous mass. Marinelli's formula was used to calculate tissue absorbed doses of 150 Gy, 200 Gy, 250 Gy and 300 Gy to the thyroids of 438 patients with multifocal and disseminated autonomy. The mean age of patients was 70+/-9 years, and the mean thyroid volume was 54+/-26 ml. Two hundred and sixty-one of the patients had at least one documented previous episode of overt hyperthyroidism. Tissue absorbed doses were adapted to the pretreatment TcTU(s): 150 Gy for a TcTU(s) of 1.5%-2.49%, 200 Gy for a TcTU(s) of 2.5%-3.49%, 250 Gy for a TcTU(s) of 3.5%-4.49% and 300 Gy for a TcTU(s) of > or =4.5%. Normalisation of TcTU(s) and thyrotropin (TSH), thyroid volume reduction and frequency of hypothyroidism and recurrent hyperthyroidism were evaluated 1 year after a single radioiodine therapy. The presented dose strategy resulted in normalisation of TcTU(s) in 96% and an increase in TSH to the normal range in 92%. Recurrent hyperthyroidism was observed in only five patients. Thyroid volume decreased from 54+/-26 before treatment to 34+/-20 ml, a mean reduction of 37%. The frequency of hypothyroidism, at 0.9%, was encouragingly low. Dose selection in accordance with pretreatment TcTU(s) can be recommended for elimination of functional autonomous tissue with a single radioiodine therapy in patients of advanced age with enlarged thyroid glands and relevant autonomous masses who are at risk of developing iodine-induced hyperthyroidism.

Topics: Adult; Aged; Aged, 80 and over; Dose-Response Relationship, Radiation; Female; Follow-Up Studies; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Prospective Studies; Radionuclide Imaging; Radiotherapy Dosage; Sodium Pertechnetate Tc 99m; Statistics, Nonparametric; Thyrotropin; Thyroxine; Triiodothyronine; Ultrasonography

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.. 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.. 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.. 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.

Topics: Female; Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland

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

Topics: Aged; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Prospective Studies; Radiography; Radionuclide Imaging; Radiotherapy Dosage; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine; Triiodothyronine

The present study analyzes the improvement of the outcome of radioidine therapy in non-immunogenic hyperthyroidism by adapting the target dose to the 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) prior to radioiodine therapy. The TcTUs is a substitute for the non-suppressible iodine turnover. The 89 patients presented with a basal thyrotropin level of < 0.1 mU/l, normal values for free triiodothyronine and thyroxine and with multifocal or disseminated thyroid autonomy. These terms describe the scintigraphic distribution pattern of autonomous iodine turnover. Thirty-two patients had a TcTUs between 1.6 and 3.2% (group A) and 57 had a TcTUs > 3.2% (group B). Fifty-five patients (three of group A and 52 of group B) were treated previously for overt hyperthyroidism with antithyroid drugs. Target doses of 150 and 200 Gy were used in both groups and 300 Gy in group B only. Six months after radioiodine therapy, a basal TSH level of > or = 0.5 mU/l as criterion of therapy success was observed in 94% of group A and in 54% of group B. Further differentiation of group B shows an increasing success rate with the target dose used: 45% after 150 Gy, 50% after 200 Gy and 90% after 300 Gy. In patients with a basal TSH level of < 0.5 mU/l after radioiodine therapy, the TcTUs was evaluated again.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Aged, 80 and over; Female; Germany; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Radiotherapy Dosage; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine; Triiodothyronine

A comparative study of high-dose (HD, carbimazole 60 mg plus thyroxine 100-150 micrograms daily) and titration-dose (TD) regimens of carbimazole was carried out in 70 patients with Graves' disease, the patients being assigned randomly to one or other regimen. The treatment was given for 1 year and follow-up was for 2 years after stopping treatment. In both groups, recurrence of hyperthyroidism occurred, most commonly during the first 6 months (35% of HD and 44% of TD). By 2 years after stopping treatment, recurrence had occurred in 50% of the HD and 66% of the TD group. The differences were not significant. Thyroid antibodies, serum thyroglobulin and pertechnetate uptake fell similarly in both groups during treatment. Cigarette smoking was similar in both the groups and did not influence the frequency of relapse. In both HD and TD groups, when relapsing patients were examined according to whether they relapsed early (within 6 months or less) or late it was found that those who relapsed late were, in respect of goitre size, pertechnetate uptake and presence of detectable plasma TSH, similar to the patients who did not relapse at all. In conclusion, the changes in the measured variables and the progress of the patients was similar whether treated by the HD or TD regimen.

Topics: Adult; Antibodies; Carbimazole; Dose-Response Relationship, Drug; Eye Diseases; Female; Graves Disease; Humans; Hyperthyroidism; Male; Middle Aged; Patient Dropouts; Prevalence; Recurrence; Smoking; Sodium Pertechnetate Tc 99m; Thyroglobulin; Thyroid Gland; Thyroxine; Titrimetry

An accurate measurement of the target volume is of primary importance in theragnostics of hyperthyroidism.. Our purpose was to evaluate the accuracy of a threshold-based isocontour extraction procedure for thyroid tissue volumetry from SPECT-CT.. Cylindrical vials with a fixed volume of 99mTcO4 at different activities were inserted into a neck phantom in two different thickness settings. Images were acquired by orienting the phantom in different positions, i.e., 40 planar images and 40 SPECT-CT. The fixed values of the isocontouring threshold for SPECT and SPECT-CT were calculated by means of linear and spline regression models. Mean, Median, Standard Deviation, Standard Error, Mean Absolute Percentage Error and Root Mean-Square Error were computed. Any difference between the planar method, SPECT and SPECT-CT and the effective volume was evaluated by means of ANOVA and posthoc tests. Moreover, planar and SPECT-CT acquisitions were performed in 8 patients with hyperthyroidism, considering relevant percentage differences greater than > 20% from the CT gold standard.. Concerning phantom studies, the planar method shows higher values of each parameter than the other two methods. SPECT-CT shows lower variability. However, no significant differences were observed between SPECT and SPECT-CT measurements. In patients, relevant differences were found in 7 out of 9 lesions with the planar method, in 6 lesions with SPECT, but in only one with SPECT-CT.. Our study confirms the superiority of SPECT in volume measurement if compared with the planar method. A more accurate measurement can be obtained from SPECT-CT.

Topics: Humans; Hyperthyroidism; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Female; Humans; Hyperthyroidism; Middle Aged; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms

Topics: Animals; Cat Diseases; Cats; Female; Hyperthyroidism; Iodine Radioisotopes; Male; Neck; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thyroid Gland

Thyroid-to-salivary ratio and percent dose uptake are the most widely recognized scintigraphic measurements. Recently, the thyroid-to-background ratio has been proposed as an alternate method. However, this method has not been validated. The purpose of this observational, cross-sectional, prospective study was to determine the location of a background region of interest (ROI) that is most reflective of blood pool activity. We also hypothesized that the thyroid-to-background ratio using this background ROI would be a better predictor of thyroid function. Fifty-six cats presented to the Virginia-Maryland College of Veterinary Medicine seeking radioiodine therapy for hyperthyroidism were enrolled in this cross-sectional study to evaluating thyroid-to-background ratio. A blood sample for measuring plasma radioactivity was collected at the time of scintigraphy. The plasma radioactivity was compared to the background ROIs in eight anatomic regions. Scintigraphic measures of thyroid-to-background and thyroid-to-salivary ratios, and percent dose were then compared to serum T4 . The heart ROI was most closely correlated with plasma pertechnetate activity (r = 0.70). Percent dose uptake was most closely correlated with serum T4 (r = 0.74), followed by thyroid-to-salivary ratio (r = 0.66) and thyroid-to-background ratio using the heart ROI (r = 0.59). Thyroid-to-background ratio using the heart background ROI is a good predictor T4 but percent dose uptake and thyroid-to-salivary ratio proved to be better predictors of T4 than any of the thyroid-to-background ratios.

Topics: Animals; Cats; Cross-Sectional Studies; Female; Hyperthyroidism; Iodine Radioisotopes; Male; Prospective Studies; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroxine

The aim of this study was to assess inter- and intraobserver variability of commonly used semi-quantitative and quantitative parameters in feline thyroid scintigraphy: thyroid to salivary gland ratio (T/S), thyroid to background ratio (T/B) and the percentage technetium pertechnetate uptake for the thyroid glands (%TcUT). These parameters are being used to diagnose thyroid disease and to assess its severity, but may be influenced by operator related factors when processing the images. Additionally, inter- and intraobserver variability of the percentage technetium pertechnetate uptake for the salivary glands was determined (%TcUSG). The study included technetium pertechnetate scans of 100 hyperthyroid cats. Variability within and between three observers was determined using a random effects model and variance components were estimated by the restricted maximum likelihood procedure. The %TcU for the thyroid and salivary glands, as well as the T/S ratio, showed little to no difference in inter- and intraobserver variability, whereas this was clearly present for the T/B ratio. Overall, the T/S ratio and %TcUSG showed a good repeatability and reproducibility with low inter- and intraobserver variabilities. Inter- and intraobserver variability was higher for the %TcUT, however variations were still considered to be acceptable. On the contrary, inter- and intraobserver variability was clearly larger for the T/B ratio. These findings suggest the preferential use of the T/S ratio or %TcU, especially in facilities with a less experienced staff.

Topics: Animals; Cat Diseases; Cats; Hyperthyroidism; Observer Variation; Radionuclide Imaging; Reproducibility of Results; Salivary Glands; Sodium Pertechnetate Tc 99m; Thyroid Gland

Thyroid scintigraphy is commonly used for evaluation of cats with hyperthyroidism, with the thyroid-to-salivary ratio (T/S) being the most common method to quantify the degree of thyroid activity and disease. Calculation of thyroid-to-background ratios (T/B) or percent thyroidal uptake of (99m) TcO(-) 4 (TcTU) has only been reported in a few studies. The purpose of this prospective, cross-sectional study was to evaluate a number of quantitative scintigraphic indices as diagnostic tests for hyperthyroidism, including the T/S, three different T/B, TcTU, and estimated thyroid volume. Of 524 cats referred to our clinic for evaluation of suspected hyperthyroidism, the diagnosis was confirmed (n = 504) or excluded (n = 20) based on results of a serum thyroid panel consisting of thyroxine (T4 ), triiodothyronine (T3 ), free T4 (fT4 ), and thyroid-stimulating hormone (TSH) concentrations. In the hyperthyroid cats, median values for TcTU, T/S, and three T/B ratios were all significantly higher (P < 0.001) than values in euthyroid suspect cats or clinically normal cats. All scintigraphic parameters were relatively sensitive and specific as diagnostic tests for hyperthyroidism, but the T/S ratio had the highest test accuracy. The T/S ratio correlated strongly with the TcTU (r = 0.85). However, the TcTU had a higher and more significant correlation (P < 0.01) with serum T4 (r = 0.76 vs. 0.64), T3 (r = 0.77 vs. 0.64), and estimated thyroid volume (r = 0.62 vs. 0.38). Overall, calculation of TcTU is an accurate diagnostic test, but also appears to be the best parameter to predict the functional volume and metabolic activity of the feline adenomatous thyroid gland.

Topics: Animals; Antithyroid Agents; Cat Diseases; Cats; Female; Hyperthyroidism; Male; Methimazole; Radionuclide Imaging; Saliva; Sodium Pertechnetate Tc 99m; Thyroid Gland

A 51-year-old woman with a personal history of vitiligo, normal thyroid hormone studies, a simple hysterectomy for multiple uterine myomas at age 35 years, and childhood adenotonsillectomy was seen for progressive hearing loss. She reported mild asthenia, cold intolerance, mild dysphagia with frequent choking while eating and drinking, and a progressive increase in inspiratory effort, especially in the supine position. Her partner described a progressively worsening history of snoring and witnessed apneic episodes, mostly in the supine position. Mild to moderate daytime sleepiness was also present.

Topics: Antithyroid Agents; Female; Goiter, Nodular; Hearing Loss; Humans; Hyperthyroidism; Lingual Thyroid; Magnetic Resonance Imaging; Methimazole; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sleep Apnea, Obstructive; Sodium Pertechnetate Tc 99m; Supine Position; Tomography, X-Ray Computed

Several studies described the ultrasound based real-time elastography (USE) having a high sensitivity, specificity and negative predictive value in the diagnosis of suspicious thyroid nodules. Recently published studies called these results into question. Until now the usefulness of USE in the diagnosis of scintigraphically hyperfunctional thyroid nodules is not examined.. This study included 135 hyperfunctional thyroid nodules of 102 consecutive patients. The following attributes of the nodules were analyzed: stiffness with the USE using scores of Rago or Asteria and ultrasound criteria using TIRADS.. 94 of the examined thyroid nodules (70%) were rated as hard (suspicious for malignancy) and 41 nodules (30%) as soft (not suspicious) with a specificity of 30%. The scoring systems of Rago and Asteria showed no significant difference. Applying the TIRADS criteria 44 nodules (33%) have a higher risk for malignancy (33 nodules TIRADS 4a, 11 nodules TIRADS 4b). Combining USE and TIRADS 32 nodules (24%) are categorized as suspicious (intersection of hard nodules that are categorized as TIRADS 4a or 4b).. Ultrasound based real-time elastography cannot identify scintigraphically hyperfunctional thyroid nodules as benign nodules reliably. Its accuracy in the assessment of at least "hot" thyroid nodules is to be questioned.

Topics: Elasticity Imaging Techniques; Female; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thyroid Nodule

This study investigated the recombinant human thyrotropin (rhTSH) stimulation test in healthy cats (group 1), cats with non-thyroidal illness (group 2) and cats with low serum total T(4) (TT(4)) and azotaemia after (131)I treatment (group 3). Serum TT(4) responses and thyroidal pertechnetate uptake after administration of 25 microg rhTSH IV were assessed. Baseline serum TT(4) was significantly lower in group 3 compared with group 1, but not between other group pairs. Serum TT(4) increased significantly in groups 1 and 2 but not in group 3 after rhTSH administration. Post-rhTSH serum TT(4) concentrations differed significantly between groups 1 and 3 and groups 2 and 3, but not between groups 1 and 2. Thyroid/salivary gland uptake ratio (T/S uptake ratio) differed only significantly between groups 1 and 3. Stimulation with rhTSH is valuable to differentiate euthyroidism from iatrogenic hypothyroidism in cats.

Topics: Animals; Azotemia; Case-Control Studies; Cat Diseases; Cats; Diagnosis, Differential; Female; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Radionuclide Imaging; Recombinant Proteins; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyroxine

This study reports on early and paradoxical aggravation of hyperthyroidism, which needs long-term treatment, in patients with Graves' disease after radioactive iodine (RAI) treatment.. Five patients (0.4%) out of 1333 consecutive patients with Graves' disease who underwent RAI treatment by using an empirical fixed dose of I between January 2000 and March 2006 revisited the emergency center because of early and markedly aggravated thyrotoxic manifestations, which seemed to differ from those for radiation-induced thyroiditis. The clinical features, changes in the laboratory, and scintigraphic findings before and after RAI treatment, and long-term follow-up of these patients were reviewed retrospectively.. The mean interval between the RAI treatment and paradoxical exacerbation of hyperthyroidism was 47.8 days (range: 28-69 days). In all five patients, the serum levels of thyroid hormones were markedly increased compared with those before the RAI treatment. The patients also exhibited an increased uptake of radioiodine or technetium-99m pertechnetate on the scintigraphy after RAI treatment. The serum levels of thyrotropin receptor antibodies were increased compared with those before the RAI treatment. Immediate and long-term treatments with antithyroid medications or second dose of RAI treatment were required in all the patients to control persistent hyperthyroidism.. The early and paradoxical exacerbation of preexisting Graves' disease, as distinct from radiation-induced thyroiditis, can occur after insufficient dose of RAI treatment for Graves' disease.

Topics: Adolescent; Adult; Female; Graves Disease; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Radiometry; Radionuclide Imaging; Radiopharmaceuticals; Receptors, Thyrotropin; Sodium Pertechnetate Tc 99m; Thyroxine; Treatment Failure

The causes of subclinical hyperthyroidism have only been reported from clinical studies.. To determine the prevalence and pathological causes of reduced serum TSH levels in subjects recruited from an epidemiological survey.. Serum TSH was measured in 7954 subjects in the 5th Tromsø study. Subjects with serum TSH<0.50 mIU/l, not using T4, without a previous diagnosis of thyroid disease, without serious concomitant disease, and younger than 80 yr, were invited for a re-examination. If low serum TSH was persistent, thyroid scintigraphy was performed.. Among the 4962 subjects that met the inclusion criteria, serum TSH was <0.50 mIU/l in 105 subjects. Twelve subjects had a suppressed serum TSH level (<0.05 mIU/l). Two of these were lost to follow-up, 4 had Graves' disease, 4 had adenoma, and 2 had multinodular goiter. In the 93 subjects with serum TSH 0.05-0.5 mIU/l, 55 were re-examined, of whom 35 had normalized their serum TSH level. In the remaining 20 subjects, 1 had Graves' disease, 6 had adenoma (of which 2 were toxic adenomas), 7 had multinodular goiter, and 6 were considered normal. Among the 521 subjects using T4, 70 (13.4%) had a suppressed serum TSH level.. Most of the subjects with a suppressed serum TSH level will be on T4 medication. Otherwise, if the suppressed serum TSH level is found by chance, this probably represents a clinically important thyroid pathology. Also, in subjects with a persistently low serum TSH level (0.05-0.5 mIU/l) most will have a pathological thyroid scan.

Topics: Adenoma; Adult; Aged; Cohort Studies; Female; Goiter, Nodular; Graves Disease; Health Surveys; Humans; Hyperthyroidism; Male; Middle Aged; Norway; Prevalence; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Neoplasms; Thyrotropin; Thyroxine

Topics: Adrenergic beta-Antagonists; Antithyroid Agents; Anxiety; Body Temperature Regulation; Diagnosis, Differential; Graves Disease; Humans; Hyperthyroidism; Male; Methimazole; Middle Aged; Muscle Weakness; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Tachycardia; Thyroid Function Tests; Tremor; Weight Loss

Hyperthyroid patients commonly complain of generalized bony aches, which are frequently overlooked due to the more prominent symptoms of cardiovascular and nervous disturbances. Hyperthyroid patients are expected to have abnormal bone metabolism as part of the generalized hypermetabolic status. The aim of this study is to verify the presence of metabolic bone superscan in association with the hypermetabolic stats in various groups of hyperthyroidism. Secondly, to correlate these superscan features with the various laboratory results in hyperthyroid patients.. Forty-five hyperthyroid patients confirmed by clinical and laboratory results were enrolled in this work. In all patients, a (99m)Tc-pertechnetate thyroid uptake scan was acquired. On a different day, total body bone scan was acquired three hours post IV injection of 555-925 MBq of (99m)Tc-MDP. Serum FT3, FT4, TSH, Ca++, alkaline phosphatase (AP) and parathyroid hormone (PTH) were monitored in all patients as markers of thyroid and bone metabolism. Ten cases with no thyroid diseases were included as a control group. Patients with thyroiditis or long history of antithyroid drugs for more than one year were excluded from the study.. The patients were subdivided into three groups: Graves disease (GD) (n = 30), toxic nodular goiter (TNG) (n = 10) and autonomous toxic adenoma (AT) (n = 5). The TSH for the whole group was significantly suppressed compared to the control group with higher suppression in the Graves disease group than in the TNG or AT groups. (99m)Tc-pertechnetate uptake values in the Graves disease group were significantly higher than the TNG and AT groups (p < 0.05). Metabolic superscan (MSS) was noted in 90% of the Graves cases, 20% in TNG and in none of the AT group. There were no significant differences regarding Ca+, AP and PTH between the Graves and non-Graves groups (p > 0.05).. Disturbances in bone metabolism are more prevalent in Graves disease than in other types of hyperthyroidism. The addition of the bone scan to the diagnostic work up of patients with Graves disease is a sensitive indicator for metabolic bone changes and could help in the future management and follow up for this group of patients.

Topics: Adult; Bone Diseases, Metabolic; Female; Humans; Hyperthyroidism; Male; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Medronate

To assess whether the risk of development of hypothyroidism after treatment with iodine 131 (131I) was associated with the pattern of sodium pertechnetate Tc 99m activity in the thyroid gland detected via scintigraphy before treatment in cats with hyperthyroidism.. Retrospective study.. 165 cats.. Medical records of cats with hyperthyroidism that had been treated with 131I (from 1990 to 2002) and had undergone scintigraphy of the thyroid gland before treatment were reviewed; data regarding signalment, scintigraphic findings (classified as unilateral, bilateral-asymmetric, bilateral-symmetric, or multifocal patterns), serum total thyroxine (T4) concentrations before treatment and prior to hospital discharge, and 131I treatment were collected. A questionnaire was sent to each referring veterinarian to obtain additional data including whether the cats subsequently developed hypothyroidism (defined as serum total T4 concentration less than the lower reference limit > or = 3 months after treatment).. 50 of 165 (30.3%) 131I-treated cats developed hypothyroidism. Hypothyroidism developed in 39 of 109 cats with bilateral, 10 of 50 cats with unilateral, and 1 of 6 cats with multifocal scintigraphic patterns of their thyroid glands. Cats with a bilateral scintigraphic pattern were approximately 2 times as likely to develop hypothyroidism after 131I treatment than were cats with a unilateral scintigraphic pattern (hazard ratio, 2.1; 95% confidence interval, 1.04 to 4.2).. Cats with hyperthyroidism that have a bilateral scintigraphic pattern in the thyroid gland before 131I treatment appear to have a significantly higher risk of subsequently developing hypothyroidism, compared with cats with a unilateral scintigraphic pattern.

Topics: Animals; Cat Diseases; Cats; Female; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Male; Radionuclide Imaging; Retrospective Studies; Risk Factors; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Hormones

Rarely may a non-hyperfunctioning thyroid nodule present as "hot" at Technetium-99m pertechnetate (99mTcO4-) and "cold" at radioiodine scintigraphy at late acquisitions. We report the case of a hyperthyroid female patient whose 99mTcO4- scintigraphy showed two "hot" nodules, whereas Iodide-131 (131I-) revealed a lack of indicator uptake by the larger, and intense uptake by the smaller nodule. The patient underwent surgery: histology demonstrated that the larger nodule, mismatched at pertechnetate vs iodine scintigraphy, was a papillary carcinoma. Our suggestion is to perform thyroid scintigraphy with radioiodine in hyperthyroid patients with more than one nodule concentrating pertechnetate, especially when an ultrasonographic pattern possibly suspect for malignancy is present.

Topics: Carcinoma, Papillary; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroid Nodule; Thyroidectomy

The purpose of the study was to assess the role of radionuclide imaging of hyperthyroid patients with no suspicion of nodules. (99)Tc(m) radionuclide scans performed on all 190 patients referred over a 2-year period with symptoms and thyroid function tests compatible with thyrotoxicosis were retrospectively reviewed. 73% of patients were referred by a hospital clinician and 27% were referred direct from the general practitioner. Referral letters and, where applicable, the clinical notes were reviewed and patients with suspected thyroid nodules were excluded. The results of (99)Tc(m) thyroid scans of the 190 patients (age range 23-93 years, mean 48 years) were reviewed. 152 (80%) patients had Graves' disease, 10 (5.3%) had Graves' disease with nodules, 6 (3.2%) had Graves' disease with non-functioning nodules, 5 (2.6%) had viral thyroiditis, 5 (2.6%) had autonomously functioning nodules and 12 (6.3%) were normal studies. Therefore, 20% of patients had a diagnosis other than solely Graves' disease. These diagnoses are important with respect to clinical management. In conclusion, routine radionuclide imaging is worthwhile, as a significant proportion of patients with clinical "Graves' disease" in this study would have received incorrect treatment without the result of this scan.

Topics: Adult; Aged; Aged, 80 and over; False Negative Reactions; Female; Graves Disease; Humans; Hyperthyroidism; Male; Middle Aged; Palpation; Radionuclide Imaging; Radiopharmaceuticals; Referral and Consultation; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Nodule; Thyroiditis

To verify the effectiveness of percutaneous ethanol injection (PEI) in the treatment of large (>30-mL) hyperfunctioning thyroid nodules.. Twelve patients (eight women, four men; age range, 26-76 years) with a large hyperfunctioning thyroid nodule (volume range, 33-90 mL; mean, 46.08 mL) underwent PEI treatment under ultrasonographic (US) guidance. US was used to calculate the volume of the nodules and to assess the diffusion of the ethanol in the lesions during the procedure. When incomplete necrosis of the nodule was depicted at scintigraphy performed 3 months after treatment, additional PEI sessions were performed.. Four to 11 PEI sessions (mean, seven) were performed in each patient, with an injection of 3-14 mL of 99.8% ethanol per session (total amount of ethanol per patient, 30-108 mL; mean, 48.5 mL). At scintigraphy after treatment in all patients, recovery of extranodular uptake, absence of uptake in the nodule, and normalization of thyroid-stimulating hormone (thyrotropin) levels were observed. In all patients, US showed volume reductions of 30%-50% after 3 months and 40%-80% after 6-9 months. Side effects were self-limiting in all patients. During the 6-48-month follow-up, no recurrence was observed.. PEI is an effective and safe technique for the treatment of large hyperfunctioning thyroid nodules.

Topics: Adult; Aged; Aged, 80 and over; Ethanol; Female; Follow-Up Studies; Humans; Hyperthyroidism; Injections, Intralesional; Male; Middle Aged; Necrosis; Retreatment; Sodium Pertechnetate Tc 99m; Thyroid Nodule; Ultrasonography

Both (201)TI and (99m)Tc-methoxyisobutyl isonitrile (MIBI) have been used in the visualization of suppressed thyroid tissue in patients with autonomously functioning thyroid nodules (AFTNs). It has been suggested that thyroid-stimulating hormone (TSH) control is not a major determinant of both tracers. However, the mechanism of thyroid uptake of these agents is controversial. In this study, we compared (201)TI and MIBI in the visualization of suppressed thyroid tissue in patients with a solitary toxic AFTN.. Thirty-two patients (13 triiodothyronine [T3] and 19 T3 + levorotatory thyroxine [T4] hyperthyroid patients) with toxic AFTNs visualized on (99m)Tc-pertechnetate scanning were included in the study. All patients underwent MIBI and (201)TI thyroid scintigraphy within a 3-d interval. The scintigrams were analyzed both visually and semiquantitatively. For the semiquantitative analysis, regions of interest (ROIs) were generated over the nodule (N) and contralateral normal lobe (E), and the mean counts in each ROI were calculated.. The N/E uptakes (mean +/- SD) for pertechnetate, MIBI, and (201)TI were 11.37 +/- 4.53, 4.76 +/- 1.38, and 1.63 +/- 0.15, respectively, in T3 + T4 hyperthyroid patients and 9.46 +/- 3.64, 2.73 +/- 0.63, and 1.57 +/- 0.23, respectively, in T3 hyperthyroid patients. Our results showed that (201)TI uptake of suppressed thyroid tissue compared with AFTN was more prominent and significantly higher than that of MIBI for both groups of patients (P = 1.08E-05 for T3 and 6.15E-09 for T3 + T4 hyperthyroidism). There was no significant difference for either pertechnetate or (201)TI (P > 0.05) when the N/E uptakes of both groups of patients were compared. However, the N/E uptake of MIBI in T3 + T4 hyperthyroid patients was significantly higher than that in T3 hyperthyroid patients (P = 6.69E-06).. Clear visualization of suppressed thyroid tissue with both (201)TI and MIBI in patients with low serum concentrations of TSH suggests that TSH is not a major factor in the thyroid uptake of either agent. (201)TI is superior to MIBI in the visualization of suppressed thyroid tissue in patients with a toxic thyroid nodule. An increased rate of metabolism in the follicular cells of AFTNs in T3 + T4 hyperthyroid patients compared with that in T3 hyperthyroid patients might be responsible for the higher N/E for MIBI compared with that for (201)TI.

Topics: Adult; Aged; Female; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Thyroid Gland; Thyroid Nodule; Thyrotropin; Thyroxine; Triiodothyronine

A case of hyperthyroid disease after total thyroidectomy is reported. An initial scintigraph with Tc-99m sodium pertechnetate confirmed the absence of uptake in the neck. The view of the pelvis revealed a rounded area of increased uptake on the left, near the sacroiliac joint (results of bone scintigraphy were negative). A wholebody scan with iodine-131 confirmed a struma ovarii that was bilateral, which occurs in 5% to 10% of patients with this condition.

Topics: Aged; Diagnosis, Differential; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Ovarian Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Struma Ovarii; Thyroidectomy

A 27-year-old woman who presented with a left thyroid nodule was found to have hyperthyroidism caused by a syndrome of inappropriate secretion of TSH. The levels of free T3, free T4 and TSH were 9.50 pg/mL, 4.05 ng/dL and 2.16 microU/mL, respectively. Magnetic resonance imaging of the head revealed a pituitary macroadenoma. The TSH response to TRH stimulation was normal and responses of other anterior pituitary hormones to stimulation tests were also normally preserved. Administration of octreotide with iodine successfully reversed hyperthyroidism prior to total resection of pituitary adenoma, which was followed by hemithyroidectomy of the left thyroid five months later. Histologically, the resected pituitary adenoma was a TSH-producing adenoma (TSH-oma) and the thyroid nodule was a papillary adenocarcinoma. Serum TSH diminished to undetectable levels immediately following pituitary adenomectomy but gradually normalized over nine months. Coexistence of a TSH-oma with thyroid cancer is very rare and only two similar cases have previously been documented. This combination raises the possibility that TSH may be involved in tumorigenesis in the thyroid gland.

Topics: Adenocarcinoma, Papillary; Adenoma; Adult; Biopsy, Needle; Female; Humans; Hyperthyroidism; Iodine; Iodine Radioisotopes; Lymphatic Metastasis; Magnetic Resonance Imaging; Neoplasms, Multiple Primary; Octreotide; Pituitary Neoplasms; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroidectomy; Thyrotropin; Thyrotropin-Releasing Hormone; Ultrasonography

A patient whose nontoxic autonomously functioning thyroid adenoma had been stable for at least 3 yr developed enlargement of the nodule and hyperthyroidism. It was assumed the hyperthyroidism was caused by evolving toxicity in the autonomous adenoma, but imaging showed the nodule had undergone infarction and the hyperthyroidism was secondary to Graves' disease. This case demonstrates the necessity of thyroid imaging in patients with nontoxic autonomously functioning thyroid adenomas when there is a change in nodule size or thyroid function which requires treatment.

Topics: Adenoma; Adult; Female; Graves Disease; Humans; Hyperthyroidism; Infarction; Iodine Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms

I-123 thyroid scintigrams performed in 349 patients were evaluated with a focus on specific thyroid gland vestiges, namely a pyramidal lobe or a thyroglossal duct. The detection of these vestiges in patients with hyperthyroidiam is indicative of autoimmune hyperthyroidism. In Graves' disease, stimulating thyrotropin (TSH) receptor antibodies cause a significantly more frequent appearance of vestiges of the thyroglossal tract. In contrast, disseminated autonomously functioning thyroid nodules rarely show a pyramidal lobe. The frequency of pyramidal lobe visualization in patients with Graves' disease differed significantly from the frequency in patients with multifocal or disseminated autonomously functioning nodules. In euthyroidism patients, the vestiges may be indicative of the diagnosis of iodine deficiency with or without latent primary hypothyroidism. In thyroid scintigraphy, the pyramidal lobe and the thyroglossal duct can be visualized more easily using I-123 instead of Tc-99m sodium pertechnetate.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Female; Graves Disease; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Gland

A retrospective study was performed to evaluate the usefulness of thallium scintigraphy for visualization of thyroid morphology and function. Moreover, applying absolute quantitation, we wished to confirm the qualitatively reduced 99Tc(m) uptake reported by Wiersinga et al. in both euthyroid and hyperthyroid patients treated with amiodarone. Over a period of 2 years (1995-96), 10 patients (group A; 2 females, 8 males, mean age 68.6 years, range 61-74 years) receiving amiodarone treatment for cardiac arrhythmias for at least 4 months were referred for exploration of either hyperthyroidism (n = 4) or for exclusion of parathyroid adenoma (n = 6). During the same period, 17 patients (group B; 10 females, 7 males, mean age 62 years, range 19-91 years) referred for Tc-Tl subtraction scintigraphy, and in whom follow-up revealed no thyroid or parathyroid pathology, were used as controls. In all patients, thyroid status was assessed by thyroid function tests. 201Tl and 99Tc(m) uptake was calculated as a percentage of the injected dose, taking account of net injected counts and background and isotope decay correction. Original images were scored using a 2-point scoring system (0 = poor, 1 = fair or good). Uptake of both 99Tc(m) and 201Tl was significantly reduced in group A (99Tc[m]: 0.16 +/- 0.21%; 201Tl: 0.30 +/- 0.21%; mean +/- S.D.) compared to group B (99Tc[m]: 1.58 +/- 1.07%; 201Tl: 0.72 +/- 0.37%) (P < 0.005). The mean relative reduction in 99Tc(m) uptake was more pronounced (90% decrease) than that of 201Tl (58% decrease). In group A, the 99Tc(m) and 201Tl image quality was poor in 10 of 10 and 8 of 10 patients respectively. In group B, the 99Tc(m) and 201Tl image quality was poor in 3 of 17 and 4 of 17 patients respectively. The decreased uptake of 201Tl may reflect the inhibitory effect of iodides on adenyl cyclase and its stimulation by TSH. In conclusion, the data presented confirm the qualitatively reduced pertechnetate uptake reported by Wiersinga et al. Furthermore, 201Tl uptake by the thyroid in euthyroid or hyperthyroid patients treated with amiodarone is also reduced. Although quantitatively less pronounced, it does not allow proper visualization of the thyroid.

Topics: Adult; Aged; Aged, 80 and over; Amiodarone; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Female; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Reference Values; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thyroid Gland

One hundred consecutive thyroid images obtained by use of Tc-99m pertechnetate, in authenticated cases of hyperthyroidism, were reviewed. Calibrated images showed that only 42 of the 200 thyroid lobes (21%) were greater than 5 cm in length. The enlarged lobes occurred in 29 patients. Of these, only 4 had a multinodular appearance (and 7 patients with smaller lobes also had multinodular glands). Neither thyromegaly (by length) nor multinodular appearance are common features of hyperthyroidism in this area. There were 12 instances of pyramidal lobes in the hyperthyroid men (12 of 26 = 46%) and 24 cases in women (24 of 74 = 32%). The site of origin of the pyramidal lobe was from the left in 17, from right in 16, and from the midline in 3 cases. During the period of review of all thyroid images, only one other case of a pyramidal lobe was found (a case of multinodular goiter).

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Female; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland

Solitary hyperfunctioning nodules of the thyroid gland are usually viewed as benign. They may present with autonomous euthyroidism but are of concern for potential progression to hyperthyroidism. Various methods of treatment are worthy of consideration.. Forty-five patients with solitary hot thyroid nodules verified by radioisotope scintiscanning were selected for treatment. Thirty-one underwent surgery, usually partial thyroidectomy. Eight euthyroid patients received no treatment, 5 underwent therapy with radioactive iodine (RAI), and 1 received thyroid suppression treatment. The cases were assessed retrospectively.. Thyroidectomy patients had no morbidity, were well, and showed 1 Hürthle cell tumor and 5 coincidental small malignancies associated with benign hot nodules, including a contralateral cancer. Untreated patients showed continuance of good health, but nodules persisted and 1 Graves' orbititis occurred. The RAI-treated patients had persistent nodularity, improved function, and 1 case of hyperparathyroidism. Thyroid feeding only caused iatrogenic toxicity and was discontinued.. There are various techniques for managing the hot nodule. Nonsurgical methods may be effective, but can result in persistent nodularity and iatrogenic sequelae. Excision had no morbidity in this series and was effective in providing immediate relief of problems present and potential.

Topics: Adenocarcinoma; Adenocarcinoma, Follicular; Adolescent; Adult; Aged; Aged, 80 and over; Carcinoma; Disease Progression; Female; Follow-Up Studies; Graves Disease; Humans; Hyperparathyroidism; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroid Nodule; Thyroidectomy; Thyroxine; Triiodothyronine

A new quantitative subtraction method of thyroid scans is proposed which shows that regional function (F) by far exceeds regional cellularity or cell density (C) in potentially toxic thyroidal areas of non-immunogenic hyperthyroidism (NIH).. A multistep processing of radioiodine and MIBI thyroid scans of patients with non-immunogenic hyperthyroidism led to normalized images of regional function excess and of perinodular enhancement. Two numeric factors were derived from regions of interest: Q (cell density ratio) comparing MIBI uptake in autonomous and suppressed areas and T (toxicity index): the maximal F/C contrast.. Q never exceeded 61; T, however, expanded toxicity levels over a range of 6-8735 with toxic adenomas (median = 165) and with hot areas of multifocal functional autonomy (median = 15). T was weakly correlated to serum TT3 (r = 0.41), but not to autonomous tissue mass, ultrasonographic or cytologic criteria.. T is governed by inherent features of autonomous tissue and the response of the imbedded thyroid tissue to TSH stimulation. This standardized technique consolidates experiences from visual analysis; the huge T range mirrors the natural evolution from compensated autonomy towards hyperthyroid, decompensated stages.

Topics: Diagnosis, Differential; Graves Disease; Humans; Hyperthyroidism; Iodine Radioisotopes; Radioimmunoassay; Radionuclide Imaging; Regression Analysis; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine; Triiodothyronine

The aim of this work was to determine the autonomously functioning volume in euthyroid and hyperthyroid goitres for prognostic and therapeutic purposes. To this end, various groups of patients were selected: individuals without evidence of thyroid disease, euthyroid patients with diffuse goitre of normal structure and function, euthyroid patients with evidence of autonomy and patients with hyperthyroidism due to autonomy. In all of them the thyroid uptake of technetium-99m was determined under exogenous suppression (TcUs) in the euthyroid state and under endogenous suppression (TcU) in the hyperthyroid state. It was demonstrated that: 1. In patients with unifocal autonomy the TcUs and TcU correlated linearly with the autonomous volume delineated and measured by sonography. 2. A nearly identical result was obtained if the mean autonomous volume in individuals without thyroid disease of 2.2 +/- 1.1 ml calculated by TcUs/TcU x total thyroid volume was used as a basis. 3. The critical autonomous volume, i.e. the volume at which hyperthyroidism will occur, was found to be 16 ml at a cumulated sensitivity and specificity of > 0.9. The method can be used to select patients for definitive treatment before hyperthyroidism occurs and to measure the autonomously functioning volume independent of its distribution within the thyroid for treatment with radioiodine. The method is easy to perform and is also an example of how a relative parameter of a function can be converted into an absolute parameter of a functioning volume.

Topics: Goiter; Humans; Hyperthyroidism; Radionuclide Imaging; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Ultrasonography

In a retrospective study 161 hyperthyroid patients without treatment were divided into 74 with immunogenic hyperthyroidism (IMH) and 87 with non-immunogenic hyperthyroidism (NIMH). The frequency of complaints and the mean hormone concentrations were significantly higher in IMH and the median thyroid volume was significantly smaller. Diffusely reduced sonographic echoes were observed in only 50% of patients with IMH compared to 5% of those with NIMH. Homogeneous distribution of 99mTc in the thyroid was observed scintigraphically in 95% of patients with IMH and in only 3% of those with NIMH. Although the median of global thyroid uptake of 99mTc was significantly higher in IMH there was a broad overlap between the two groups. The mean hormone production is higher in IMH than in NIMH. In order to separate IMH and NIMH, several criteria have to be employed which differ concerning their diagnostic significance.

Topics: Humans; Hyperthyroidism; Middle Aged; Retrospective Studies; Sodium Pertechnetate Tc 99m; Ultrasonics

The effect of a standard 555 MBq 131I dose in ablating the thyroid gland was investigated in 116 consecutive hyperthyroid patients. Fifty-one had Graves' disease, 50 a multinodular toxic goitre and 15 had a solitary toxic nodule. 555 MBq 131I was given regardless of size or type of the gland and severity of the disease. Within one year after this dose hypothyroidism was induced in 41% of patients with Graves' disease, but in only 13% with a solitary toxic adenoma, and 6% with a multinodular gland. Forty-eight percent of the patients with a multinodular gland, 33% with Graves' disease and 13% with a solitary toxic nodule were still hyperthyroid. Since this so called ablative treatment only accomplishes hypothyroidism in 26/116 (23%) of our patients and results seem unpredictable 131I treatment adjusted according to gland size and type aiming at achieving euthyroidism could be contemplated.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Female; Goiter; Graves Disease; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Radiation Dosage; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Neoplasms

The authors describe a patient with primary hyperparathyroidism who had a large mediastinal parathyroid adenoma that avidly concentrated both Tc-99m pertechnetate and Tl-201. This unusual finding is presented as another potential reason for false-negative findings in Tc-99m/Tl-201 subtraction scintigraphy in hyperparathyroidism.

Topics: Adenoma; False Negative Reactions; Female; Humans; Hyperthyroidism; Middle Aged; Parathyroid Neoplasms; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes

Topics: Adult; False Positive Reactions; Female; Humans; Hyperthyroidism; Radionuclide Angiography; Sodium Pertechnetate Tc 99m

Striking thyroidal uptake of Tc-99m pertechnetate was observed during the course of a perfusion lung scan performed with Tc-99m MAA to rule out pulmonary embolism in a 49-year-old man. There was no evidence of gastric pertechnetate activity. Radiochemical purity analysis of the Tc-MAA by chromatography in normal saline revealed 98.8% tagging, with 1.2% free pertechnetate. We estimate that a maximum of 60 microCi (2.2 MBq) of pertechnetate was available for thyroid trapping. This amount, given to a euthyroid volunteer studied with conventional gamma camera lung perfusion settings, failed to visualize the thyroid. A follow-up radioiodine thyroid uptake of the patient was markedly elevated, as was his thyroid function tests (T3,T7,T7). When diffuse intense thyroid gland radioactivity is seen during scintigraphy with a technetium radiopharmaceutical (e.g., bone and lung scans), consideration should be given to the possibility of hyperthyroidism. If gastric activity is not concomitantly seen, hyperthyroidism secondary to diffuse hyperplasia of the gland is probably present.

Topics: Humans; Hyperthyroidism; Male; Middle Aged; Pulmonary Embolism; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Aggregated Albumin; Ventilation-Perfusion Ratio

The records of 107 patients who had had thyroid 99m Tc pertechnetate uptake measured, were reviewed. In patients with normal serum thyroxine (T4) and thyroid stimulating hormone (TSH), 35 of 36 with normal uptake and three with high uptake were clinically euthyroid. In patients with high serum T4 and low TSH, seven had normal and 29 had high uptake and all were clinically hyperthyroid. In patients with normal serum T4 and low TSH, 10 of 11 with high uptake were clinically hyperthyroid whereas only two of 18 with normal uptake were. The sensitivity, specificity and positive predictive value of pertechnetate uptake measurements were 83%, 94%, and 91%, respectively. The measurement of pertechnetate uptake is a rapid investigation and may help in the interpretation of patients with undetectable serum TSH found in the presence of normal serum T4.

Topics: Adult; Aged; Humans; Hyperthyroidism; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Thyrotropin; Thyroxine

In 104 euthyroid patients with goiter and suspected thyroid autonomy two thyroid scintiscans with quantification of the TcTU were performed before (TcTUo) and after exogeneous TSH suppression (TcTUs). In 15 patients with subnormal TSH before suppression the TcTUs revealed no difference to the TcTUo. In contrast to the TcTUo, in euthyroid patients the TcTUs is not relevantly influenced by individual iodine supply. In euthyroid goitreous patients with normal TSH a TcTUo less than 2.0% resulted in a TcTUs less than 1.1% in all 22 cases and, therefore, in these patients a scintiscan after TSH suppression is not necessary, because no relevant mass of functional autonomous tissue can be expected. In all other patients with normal TSH only the TcTUs is relevant for identification of thyroid autonomy. Autonomy with a TcTUs greater than 1.5% and, consequently, with a suspected higher risk of hyperthyroidism after iodine contamination was found in 19% (17/89) of the goitreous patients with normal TSH.

Topics: Euthyroid Sick Syndromes; Homeostasis; Humans; Hyperthyroidism; Iodine; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyrotropin; Triiodothyronine

99mTc-pertechnetate uptake was estimated 8-13 weeks after radioiodine therapy for hyperthyroidism in 132 patients in order to evaluate the usefulness of the uptake test in predicting both persisting hyperthyroidism and the early onset of hypothyroidism during the first year after therapy. The estimation was simple, the result immediately available, and its sensitivities, positive predictive value and its overall accuracy (83%) compared favourably with that of in-vitro tests, FT4I (75%) and FT3I (80%), carried out on the same occasions during the early follow-up period. Pertechnetate uptake can be a useful guide to management by promptly identifying patients likely to need further radioiodine therapy and those with transient or permanent hypothyroidism. The study confirmed some previous findings that hypothyroidism was more frequent in patients with thyroid antibodies and less frequent in patients with nodular thyroids, and it also indicated that hypothyroidism was more frequent in those treated with carbimazole before and after radioiodine, and that hyperthyroidism was more likely to persist in those treated with carbimazole before or after radioiodine.

Topics: Follow-Up Studies; Humans; Hyperthyroidism; Hypothyroidism; Iodine Radioisotopes; Prognosis; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Topics: Adenoma; Adolescent; Choristoma; Diagnosis, Differential; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Syndrome; Thyroid Gland; Thyroid Neoplasms; Ultrasonography

A practical approach to the hyperthyroid patient with a single lobe visualized on thyroid scintigraphy, and its impact on therapy is discussed. An illustrative case is also presented.

Topics: Adenoma; Adult; Diagnosis, Differential; Female; Humans; Hyperthyroidism; Iodine Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroid Gland; Thyroid Neoplasms; Ultrasonography

Topics: Aged; Female; Humans; Hyperthyroidism; Middle Aged; Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium; Time Factors

Radionuclide thyroid imaging was performed in 872 consecutive patients with hyperthyroidism. Of these, 84% were found to have diffuse toxic hyperplasia (Graves' disease), while 12% had autonomously functioning nodules (Plummer's disease), 3% had Graves' disease developing in a multinodular gland, and in the remaining 1%, either a clear diagnosis could not be established or the hyperthyroidism was due to thyroiditis or the Jod-Basedow phenomenon. It was found that a thyroid scan seldom provides additional diagnostic information in patients with Graves' disease when a diffuse goitre is present. However, if patients are to be treated with radioiodine (131I), thyroid imaging with tracer quantitation can replace a 24-h 131I uptake measurement, this having the advantages that the patients are required to attend only once, and that the gland size can be measured. In addition, visual confirmation of tracer uptake by the thyroid is obtained and patients with thyroiditis will not receive inappropriate therapy. When single or multiple thyroid nodules are palpated, a thyroid scan is crucial in establishing an accurate diagnosis, as it is not otherwise possible to differentiate between Plummer's disease and Graves' disease developing in a multinodular gland. Indeed, in 20 of our 63 patients (32%) with single autonomously functioning nodules, the initial clinical assessment had been incorrect.

Topics: Adenoma; Adolescent; Adult; Aged; Child; Diagnosis, Differential; Female; Goiter, Nodular; Graves Disease; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Syndrome; Thyroid Gland; Thyroid Neoplasms

Topics: Humans; Hyperthyroidism; Hypothyroidism; Sodium Pertechnetate Tc 99m; Thyroxine; Triiodothyronine

The rare presentation of hyperthyroidism caused by an intrathoracic goiter with a normal-sized cervical thyroid gland is described. The toxic intrathoracic goiter demonstrated avid uptake of [131I] and [99mTc]pertechnetate, with comparatively faint isotopic accumulation seen in the cervical thyroid. A chest roentgenogram and radioisotope scan should be mandatory in cases of hyperthyroidism having no cervical thyroid enlargement to explore the possibility of a toxic intrathoracic goiter.

Topics: Female; Goiter, Substernal; Humans; Hyperthyroidism; Iodine Radioisotopes; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The place of scintigraphy and ultrasonography in diagnosis was analysed retrospectively in a series of 526 patients with confirmed thyroid autonomy. Male:female ratio was 1:4.6; peak age incidence was in the sixth decade. 5.6% of patients were younger than 30 years and in each case had a sonographic focus. A normal thyroid size was found in 6.5% on palpation and in 10% by ultrasound. Normal thyroid function was found in 287 patients (56%), of whom 48% had a positive TRH test, the remainder being hyperthyroid. Unilocular autonomy was present in 57%, multilocular in the remainder. With increasing degree of autonomy there was an increase in echo-density. In 351 patients (74%) the adenoma was echo-poor, in 16% echo-normal and in 10% echo-dense. Focal findings on sonography were noted in 94% of patients. The incidence of thyroid carcinoma was 1.5% (2 of 136 patients with goitre resection), the carcinoma not being located in the autonomous tissue. It is concluded that a thyroid of normal size does not exclude autonomy. Patients younger than 30 years require scintigraphic examination only if there are focal signs. Echogenicity of a thyroid focus does not correlate with function. The incidence of cancer in the presence of autonomy is low. There was no case of thyroid carcinoma in the autonomous region.

Topics: Adult; Aged; Female; Humans; Hyperthyroidism; Male; Middle Aged; Radionuclide Imaging; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Diseases; Thyroid Function Tests; Thyroid Gland; Thyroid Neoplasms; Thyrotropin-Releasing Hormone; Ultrasonography

Topics: Amiodarone; Humans; Hyperthyroidism; Iatrogenic Disease; Iodine; Iodine Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroiditis; Thyroxine

Anamnestic iodine contamination and medication with thyroid drugs were registered in 260 patients of a clinical thyroid care unit and 200 patients of a thyroid doctor's office in the southern German endemic goiter region. We found in the university clinic 54% patients with interfering factors, 30% with iodine contamination and 20% with multiple interferences. In the physician's practice there were 18%, nearly all treated with thyroid hormone. The influence of those factors on thyroidal technetium uptake and the resulting restriction on its diagnostic value is discussed.

Topics: Antithyroid Agents; Drug Interactions; Goiter; Humans; Hyperthyroidism; Iodine; Iodized Oil; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Diseases; Thyroid Gland; Thyroid Hormones

In 255 patients (normals: group I, n = 30; nontoxic goitres: group II, n = 134; toxic goitres without ophthalmopathy: group III, n = 63; Graves' disease: group IV, n = 28) a TSH-receptor-autoantibody-assay (TRAK assay) for detection of thyrotropin-binding inhibiting antibodies (TBIAb) was tested and 99mTcO4-uptake (TcTU) was measured. Normal TcTU (range: 1.5-5.5%) and normal TRAK values (normal limit: F less than 11%) were only found in group I. An increased TcTU was found in group II in 22.4% (increased TRAK values only in 2.2%). In group III an increased TcTU was measured in 34.9% of the patients (all with normal TRAK titers). The stimulation of the TSH-receptor in immunogenic hyperthyroidism by TBIAb could be demonstrated by increased TRAK values in 71.4% of the patients with Graves' disease. In correlation, TcTU was also increased in 82.1% of the patients in group IV. As the measurement of TcTU can be helpful in differential diagnosis, the functional imaging with gamma camera and computer is today a conditio sine qua non, especially in suspected hyperthyroidism.

Topics: Autoantibodies; Graves Disease; Humans; Hyperthyroidism; Radionuclide Imaging; Receptors, Cell Surface; Receptors, Thyrotropin; Sodium Pertechnetate Tc 99m

Thyroid disease is common in developing countries and its management is based on the measurement of thyroid function and the investigation of thyroid masses. This report discusses techniques and outlines a strategy for the measurement of thyroid function using radioimmunoassays of thyroid-related hormones in the blood. It makes proposals for the evaluation of thyroid morphology using echography, pertechnetate imaging and fine needle biopsy. Note is taken of the difficulties facing laboratories in developing countries and the International Atomic Energy Agency is concerned with the practical assessment of these recommendations and of any alternative proposals in this field.

Topics: Biopsy; Developing Countries; Goiter; Humans; Hyperthyroidism; Radioimmunoassay; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Diseases; Thyroid Function Tests; Thyroid Gland; Thyroid Hormones; Thyroid Neoplasms; Thyroiditis

A 70-yr-old woman presented with hyperthyroidism and metastatic follicular carcinoma of the thyroid. The blood level of thyroid stimulating immunoglobulin (TSIg) was elevated. A total thyroidectomy was performed. One month later she remained hyperthyroid. Three weeks after therapy with 218 mCi of I-131 sodium iodide, the patient was euthyroid. Six months after the initial radioiodide therapy, she was again hyperthyroid and was given a second oral treatment dose of I-131 (220 mCi). Five months later, the patient had again become euthyroid. It is likely that initially the woman's metastases were producing sufficient hormone to render her hyperthyroid. After thyroidectomy and two large doses of radioiodide, she has remained euthyroid without having to take exogenous hormone. The blood level of TSIg had become undetectable. Based on this finding, we offer a tentative classification of the causes of hyperthyroidism in patients with thyroid carcinoma.

Topics: Adenocarcinoma; Aged; Female; Humans; Hyperthyroidism; Immunoglobulin G; Immunoglobulins, Thyroid-Stimulating; Iodine Radioisotopes; Paraneoplastic Endocrine Syndromes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroidectomy

To assess the value of routine thyroid scintigraphy in the differential diagnosis of hyperthyroidism and as a guide to I-131 therapy, we prospectively examined 100 consecutive hyperthyroid patients referred for a 24-hr radioiodine uptake and I-131 therapy. The nuclear medicine physician recorded his preimaging diagnostic impression and therapeutic plan for each patient. After the [ 99mTc ] pertechnetate image, the patient was reassessed to determine whether the image induced any change in the diagnosis or therapeutic plan. Seventy-nine of 80 patients with diffuse goiter to palpation, had scintigrams demonstrating no discrete focal defects and were diagnosed as Graves' disease; thus the scintigram did not contribute useful information. In 17 of 20 patients with uninodular or multinodular goiters, the image was necessary to clarify the final diagnosis and therapeutic plan. Thus, selective use of thyroid scintigraphy should decrease the number of scintigrams performed before I-131 therapy for hyperthyroidism, without compromising diagnostic accuracy or therapeutic success.

Topics: Adult; Aged; Female; Graves Disease; Humans; Hyperthyroidism; Iodine Radioisotopes; Male; Middle Aged; Prospective Studies; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Gland

Topics: Angiography; Humans; Hyperthyroidism; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Gland

Topics: Humans; Hyperthyroidism; Infant, Newborn; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Gland

Topics: Antithyroid Agents; Basal Metabolism; Endocrinology; Feces; Humans; Hyperthyroidism; Hypothyroidism; Iodine Isotopes; Male; Metabolism; Perchlorates; Radioisotopes; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Technetium; Thyroid Function Tests; Thyroid Gland; Thyrotropin; Urine