sodium-pertechnetate-tc-99m and technetium-tc-99m-tetrofosmin

Topics: Diagnosis, Differential; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Thyroid Gland; Thyroid Neoplasms; Thyroid Nodule; Ultrasonography

We studied the significance of technetium-99m tetrofosmin scintigraphy in patients with subacute thyroiditis (SAT). Six patients with SAT, who had painful goitre with thyrotoxicosis, underwent 99mTc-pertechnetate scintigraphy and 99mTc-tetrofosmin imaging during the acute and recovery stages of SAT. The thyroid uptake ratio of tetrofosmin was compared with the clinical parameters associated with SAT. 99mTc-pertechnetate scintigraphy showed markedly reduced uptake in the thyroid during the acute stage of SAT, suggesting that the appropriate metabolic pathway is not functioning. Conversely, 99mTc-tetrofosmin images showed diffuse increased uptake in the thyroid region on early and delayed imaging. Tetrofosmin images in the acute stage and in the recovery stage of SAT showed different clearance curves for tetrofosmin uptake. The uptake ratio assessed as thyroid uptake/background (T/B) correlated with the serum C-reactive protein concentration. In conclusion, 99mTc-tetrofosmin uptake may reflect the inflammatory process associated with SAT, and thus this tracer may have potential as a marker of disease activity and severity.

Topics: Adult; Female; Humans; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Function Tests; Thyroiditis, Subacute; Ultrasonography, Doppler, Color

Radioisotope methods have shown to be useful in the non-invasive diagnosis of thyroid nodules over the past years. The present prospective study aims to evaluate the efficacy of gamma imaging using single and dual tracer using Tc-99m pertechnetate and Tc-99m tetrofosmin for evaluation and management of thyroid nodules.. Dynamic (perfusion) imaging was performed after injecting 148-185 MBq (4-5 mCi) of Tc-99m pertechnetate followed by static imaging. A second, dynamic (perfusion) imaging study within same week was performed with 296-370MBq (8-10mCi) of Tc-99m tetrofosmin on same group of patients followed by early and delayed images. Results of radionuclide perfusion scan from both studies were compared qualitatively with postsurgical histopathology or fine needle aspiration cytology (FNAC).. Total 65 nodules in 50 patients were included in the study. With single tracer, the specificity and accuracy of Tc-99m pertechnetate was 23% and 45% and for Tc-99m tetrofosmin scan was 40% and 49%. When dual tracers were evaluated for the same group of patients, the specificity was 56% and accuracy was 55%.. Dual Tracer technique with Tc-99m pertechnetate and Tc-99m tetrofosmin could be helpful in selecting nodules need surgical intervention. This technique can be used for convenient and rapid diagnostic evaluation of thyroid nodules non-invasively. We suggest a combination of fine needle aspiration biopsy and dual use of Tc-99m-pertechnetate and Tc-99m-tetrofosmin as a routine diagnostic approach to thyroid nodules.

Topics: Adolescent; Adult; Aged; Child; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Nodule; Young Adult

Primary hyperparathyroidism (pHPT) is an endocrine disease with the third highest incidence of all endocrine disorders after diabetes mellitus and hyperthyroidism. pHPT is typically caused by a solitary parathyroid adenoma, less frequently by multiple parathyroid gland disease (MGD) and rarely by parathyroid carcinoma. Secondary hyperparatyroidism (sHPT) is a common complication in patients with chronic renal failure. The aim of this study was to estimate sensitivity of dual tracer 99mTc-tetrofosmin and 99mTc-pertechnetate subtraction scintigraphy in detection of abnormal parathyroid glands in patients with pHPT and sHPT confirmed by histopathology.. In 46 patients, (77 abnormal parathyroid glands), 30 with pHPT and 16 with sHPT parathyroid scintigraphy was done preoperatively. All the patients had histopathological confirmation of diagnosis. Abnormal parathyroid glands weighted from 0.1 to 7 g. After iv injection dynamic scintigraphy during 25 minutes (one frame-one minute) using 555 MBq of 99mTc-tetrofosmin, and three hours latter using 111 MBq of 99mTc/pertechnetate was performed. 99mTc-tetrofosmin dynamic study was followed by static scintigraphy of the neck and chest 30 minutes, 1, 2 and 3 hours after iv injection.. An abnormal scintigraphic finding was found in 44 of 46 patients with sensitivity of 96%. In pHPT sensitivity was 93% (28 of 30 patients, and 28 of 30 glands). In sHPT scintigraphy was abnormal in all the patients (sensitivity 100%). In the patients with sHPT scintigraphy detected 30 of 47 abnormal parathyroid glands (sensitivity 64%). An overall sensitivity of scintigraphy per gland, for pHPT and sHPT in detecting 58 of 77 abnormal parathyroid glands was 75%.. An abnormal scintigraphic result per patient was found in 44 patients (sensitivity 96%) and 58 of 77 abnormal parathyroid glands were detected (sensitivity 750/0). A high sensitivity of dual tracer subtraction 99mTc-tetrofosmin/99mTc-pertechnetate parathyroid scintigraphy in detecting abnormal parathyroid glands in primary and secondary hyperparathyroidism was achieved.

Topics: Female; Humans; Hyperparathyroidism; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m

Spindle epithelial tumor with thymus-like differentiation (SETTLE) of the thyroid is a rare tumor that occurs habitually in children and young adults. To date, about 20 cases of SETTLE have been reported in the English medical literature. It is considered to be a tumor of low malignancy with a favorable outcome, but delayed blood-borne metastases have been reported (sometimes over 20 years after initial treatment). In the current report, the authors describe an interesting case of SETTLE in a young woman. Double phase Tc-99m tetrofosmin scintigraphy showed accumulation of the tracer in the thyroid mass.

Topics: Adult; Female; Humans; Nevus, Epithelioid and Spindle Cell; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms

Tc-tetrofosmin seems to show a prolonged thyroid retention when compared with Tc-sestamibi; this may explain its poorer performance in the dual-phase parathyroid scintigraphy. In order to verify objectively whether and to what extent Tc-sestamibi and Tc-tetrofosmin uptake and retention differ in the thyroid gland, we performed a head-to-head comparison between the tracers in 86 euthyroid subjects enrolled in five centres. Data were compared with those of Tc-pertechnetate obtained from the same subjects. For comparison purposes, quantitative data from the salivary glands were also obtained. Tc-sestamibi showed a higher early thyroid uptake (2.26+/-0.52 vs. 2.01+/-0.49, respectively; P<0.002) and a lower retention (1.4+/-0.37 vs. 1.65+/-0.58, respectively; P<0.002) when compared with Tc-tetrofosmin. This finding provides an objective basis for the poorer results of Tc-tetrofosmin in dual-phase parathyroid scintigraphy. Delayed Tc-tetrofosmin salivary gland uptake was unexpectedly high and approached the Tc-pertechnetate value (2.29+/-0.56 vs. 2.46+/-0.75, respectively; P =not significant). This finding should be kept in mind in order to avoid interpretation pitfalls in thyroid and parathyroid imaging with Tc-tetrofosmin, as well as in other oncological imaging of the neck region. This study definitely establishes that Tc-tetrofosmin and Tc-sestamibi are not twin but rather sibling tracers.

Topics: Biological Transport; Humans; Hyperparathyroidism; Italy; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Salivary Glands; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Thyroid Gland; Tissue Distribution

Adsorption of radiopharmaceuticals onto disposable syringes has been reported to amount to levels of almost 50%. Data on adsorption of radiopharmaceuticals onto materials used for in vitro studies are extremely limited. We assessed the extent of adsorption of 99Tc(m) hexakis(2-methoxyisobutylisonitrile) (99Tc(m)-MIBI), 99Tc(m)-tetrofosmin, 99Tc(m)-furifosmin and 99Tc(m)O4 onto tubes used for in vitro measurement of cellular uptake of these radiopharmaceuticals. The influence on adsorption of different incubation media, temperature and time of incubation was evaluated. Total (not corrected for adsorption) uptake was compared with corrected, net cellular uptake in SK-BR-3, MCF-7 and liposarcoma cell lines. Values of adsorption ranging from 0.94+/-0.13% to 7.07+/-0.46% were found. The extent of adsorption of all the radiopharmaceuticals varied with the type of incubation medium and the incubation temperature. With 99Tc(m)-furifosmin, adsorption was dependent on the incubation time as well on the incubation temperature and some of the incubation media investigated. Our findings indicate that systematic investigations to evaluate the adsorption of radiopharmaceuticals onto materials used during in vitro studies of cellular uptake should be considered a mandatory aspect of quality control.

Topics: Adsorption; Furans; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Tumor Cells, Cultured

In this study we examined the delivered activity of radiopharmaceuticals injected into patients and the various factors which lead to incomplete delivery. Four commonly used 99Tcm radiopharmaceuticals were included, namely pertechnetate, methylene diphosphonate (MDP), macro-aggregated albumin (MAA) and tetrofosmin. There was no appreciable residual activity after injection of pertechnetate and MDP other than that due to the dead space in syringes (0.06 ml, 4% of measured activity). However, there was considerable residual activity following an MAA injection. This was particularly dependent on the radiopharmaceutical residence time in the syringe prior to injection. If MAA was pre-dispensed there was up to 80% of activity remaining in the syringe following injection. We have shown that this activity is not bound and can be decreased by agitating the syringe prior to the injection. For tetrofosmin, the activity remaining in the syringe was shown to be mostly due to adsorption of the tetrofosmin onto the plastic syringe (up to 30% of the activity); in particular, onto the rubber plunger. The amount of binding probably depends on the formulation of the rubber plunger and the plastic barrel, which varies between manufacturers. Of the three commonly used syringe brands (Becton-Dickinson, Sherwood, and Braun syringes) the Braun syringes were shown to have the least binding (6%) and would be most suitable for tetrofosmin injection. We recommend the use of Braun syringes for tetrofosmin. We also recommend that pre-dispensed MAA injections should be gently agitated before injection into the patient. No special precautions are necessary for pertechnetate or MDP injections.

Topics: Adsorption; Kinetics; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Syringes; Technetium; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Medronate

99Tcm-tetrofosmin (Myoview, Amersham Healthcare) is widely used as a radiopharmaceutical for myocardial perfusion imaging. Control of its radiochemical purity after reconstitution is usually performed by means of ITLC-SG paper chromatography in a mobile phase of methylene chloride/acetone (65/35), as recommended by the manufacturer. The present study describes the application of tetrahydrofuran in phosphate buffer for the development of 99Tcm-tetrofosmin on ITLC-SG strips. The use of this mobile phase significantly improves the separation between labelled tetrofosmin and unbound pertechnetate. The time for development is about 1 min and the solvent is stable for at least 1 year. In addition, the volume spotted on the strip does not affect the migration of 99Tcm-tetrofosmin. The labelling efficiency of 99Tcm-tetrofosmin can successfully be monitored by means of this method as a daily routine procedure.

Topics: Chromatography, Paper; Chromatography, Thin Layer; Drug Stability; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Solvents

Topics: Adenoma; Adult; Humans; Hypercalcemia; Male; Mediastinal Neoplasms; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m

In-vivo visualisation and quantification of the extent and time-frame of cell death after acute myocardial infarction would be of great interest. We studied in-vivo cell death in the hearts of patients with an acute myocardial infarction using imaging with technetium-99m-labelled annexin-V-a protein that binds to cells undergoing apoptosis.. Seven patients with an acute myocardial infarction and one control were studied. All patients were treated by percutaneous transluminal coronary angioplasty (six primary and one rescue), resulting in thrombolysis in myocardial infarction (TIMI) III flow of the infarct-related artery. 2 h after reperfusion, 1 mg annexin-V labelled with 584 MBq Tc-99m was injected intravenously. Early (mean 3.4 h) and late (mean 20.5 h) single-photon-emission computed tomographic (SPECT) images of the heart were obtained. Routine myocardial resting-perfusion imaging was also done to verify infarct localisation.. In six of the seven patients, increased uptake of Tc-99m-labelled annexin-V was seen in the infarct area of the heart on early and late SPECT images. No increased uptake was seen in the heart outside the infarct area. All patients with increased Tc-99m-labelled annexin-V uptake in the infarct area showed a matching perfusion defect. In a control individual, no increased uptake in the heart was seen.. Increased uptake of Tc-99m-labelled annexin-V is present in the infarct area of patients with an acute myocardial infarction, suggesting that programmed cell death occurs in that area. The annexin-V imaging protocol might allow us to study the dynamics of reperfusion-induced cell death in the area at risk and may help to assess interventions that inhibit cell death in patients with an acute myocardial infarction.

Topics: Aged; Angioplasty, Balloon, Coronary; Annexin A5; Apoptosis; Cell Death; Coronary Circulation; Coronary Vessels; Female; Follow-Up Studies; Heart; Humans; Image Processing, Computer-Assisted; Injections, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Protein Binding; Radiopharmaceuticals; Reperfusion Injury; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Tomography, Emission-Computed, Single-Photon

The aim of the study was to quantitatively compare the scintigraphic images of the thyroid and abnormal parathyroid glands obtained with technetium-99m tetrofosmin and thallium-201 in patients with hyperparathyroidism. Forty-six patients with hyperparathyroidism underwent (201)Tl (74 MBq), (99m)Tc-pertechnetate (74 MBq) and (99m)Tc-tetrofosmin (555-740 MBq) scintigraphy in a single session. Image analysis included the computation of the thyroid/background ratio in the whole study population and the parathyroid/background ratio, parathyroid/thyroid ratio and diagnostic sensitivity in 17 patients who underwent parathyroid surgery. The pertechnetate subtraction technique was used. (201)Tl and (99m)Tc-tetrofosmin showed a similar thyroid/background ratio (1.79+/-0.41 and 1.81+/-0. 47, respectively, P=NS); however, (99m)Tc-tetrofosmin showed a higher parathyroid/background ratio than (201)Tl (2.06+/-0.54 vs 1. 79+/- 0.50, P=0.007). Despite the superior quality of (99m)Tc-tetrofosmin images, both tracers showed identical sensitivity in detecting enlarged parathyroid glands in patients with primary hyperparathyroidism (89%) and in those with secondary hyperparathyroidism (50%).

Topics: Adenoma; Female; Humans; Hyperparathyroidism; Hyperparathyroidism, Secondary; Male; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thyroid Gland

The aim of the work was to study the diagnostic value of Tc-99m tetrofosmin to localize anomalous parathyroid glands in patients with hyperparathyroid disease.. We studied 31 patients, 19 with primary and 12 with secondary hyperparathyroid disease. Five of these patients were renal graft recipients. All patients underwent surgery. Each patient was injected with 555 to 740 MBq (15 to 20 mCi) Tc-99m tetrofosmin. Subsequently, radionuclide images were acquired 15 and 120 minutes after injection using a low-energy, all-purpose, parallel-hole collimator. Pertechnetate thyroid scintigraphy was obtained in nine cases (24 to 48 h later) when the thyroid activity made it difficult to identify the parathyroid glands.. All cases showed tracer uptake as early as 15 minutes after injection. In the group of patients with primary hyperparathyroid disease, 15 showed focal uptake in a parathyroid gland, and surgery revealed an adenoma in the same location. In one patient with hyperplasia, scintigraphy identified only two of four diseased glands. In the three remaining cases, scintigraphy showed focal uptake in the lower parathyroid gland, whereas at surgery the abnormal gland was located in the upper pole. In the secondary hyperparathyroidism group, seven patients showed diffuse tracer uptake in two or more glands, and histologic analysis confirmed hyperplasia in all of them. Five cases showed focal uptake, with three evaluated after surgery (uptake in the only remaining gland); one of them was a renal graft recipient, and the remaining patient had chronic renal failure and was receiving hemodialysis.. Our results suggest that Tc-99m tetrofosmin may be a suitable tracer for preoperative detection and screening of anomalous parathyroid glands. The earlier images at 15 minutes were better than those at 120 minutes. Tc-99m tetrofosmin is cleared more slowly from the normal thyroid than is Tc-99m sestamibi, and both of these tracers may give better results than the old pertechnetate TI-201 subtraction technique.

Topics: Adenoma; Adult; Aged; Evaluation Studies as Topic; Female; Humans; Hyperparathyroidism; Hyperparathyroidism, Secondary; Hyperplasia; Kidney Failure, Chronic; Kidney Transplantation; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Renal Dialysis; Sodium Pertechnetate Tc 99m; Subtraction Technique; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Thyroid Gland; Time Factors

The aim of the work was to study the diagnostic value of 99mTc-tetrofosmin to localize anomalous parathyroid glands in patients with hyperparathyroidism.. We have studied 33 patients: 12 with primary and 21 with secondary hyperparathyroidism, 9 of them renal graft recipients. Sixteen patients underwent surgery, 12 with primary and 4 with secondary hyperparathyroidism. All patients were injected with 740 MBq of 99mTc-tetrofosmin. Subsequently at 15, 30 and 60 minutes images were acquired for 300 seconds using a pin-hole collimator. A pertechnetate thyroid scintigraphy was obtained in 7 cases (24-48 h later) when the thyroid activity made difficult the identification of parathyroid glands.. In the group of patients with primary hyperparathyroidism, all cases showed a focal uptake in lower right localization. In the secondary hyperparathyroidism group, 12 patients showed diffuse tracer uptake in two or more glands and histology confirmed hyperplasia in four of them. Seven cases showed a greater focal uptake in a gland: two of them were renal graft recipients and three were chronic renal failure cases in haemodyalisis, and two were evaluated postsurgery showing uptake in the remnant parathyroid gland. The two remaining patients had a normal scintigraphy and corresponded to two false negative cases. In conclusion, our results suggest that 99Tc-tetrofosmin may be used as a suitable tracer for preoperative detection and screening of anomalous parathyroid glands.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Female; Humans; Hyperparathyroidism; Hyperparathyroidism, Secondary; Hyperplasia; Kidney Failure, Chronic; Kidney Transplantation; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Postoperative Complications; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland

The efficacy of 99mTc-tetrofosmin for the detection of parathyroid lesions was investigated prospectively in patients with hyperparathyroidism referred for surgical treatment.. Twenty-seven patients with primary and 18 with tertiary hyperparathyroidism were studied. Twelve patients had undergone one or more previous neck explorations. Static imaging with 201Tl was performed first, immediately followed by a 30-min 99mTc-tetrofosmin dynamic study. Delayed views of up to 3 hr postinjection were also obtained. Technetium-99m-pertechnetate was used for thyroid delineation. The tetrofosmin/99mTc-pertechnetate subtraction scan (TF/TC), the single-tracer washout technique and the thallium/technetium subtraction (TL/TC) were compared. Quantification of relative uptakes of tracers in the thyroid and abnormal parathyroids was accomplished by measuring activity within regions of interest. Kinetics of tetrofosmin in the thyroid and abnormal parathyroids were studied by evaluating the plots of the parathyroid to thyroid ratios against time as well as by calculation of the half-clearance times from the slow component of the time-activity curves.. The overall sensitivity, specificity and accuracy of TF/TC and TL/TC were 76%, 92% and 83% and 52%, 85% and 65%, respectively. The respective sensitivities were 87% and 70% for adenomas and 72% and 46% for hyperplasia. The parathyroid-to-thyroid activity ratios of tetrofosmin were significantly higher than those of thallium (p < 0.001). The tetrofosmin single-tracer washout study was less accurate than the subtraction technique (overall sensitivity and specificity, 70% and 69%, respectively). The washout properties of tetrofosmin in abnormal parathyroids were not substantially different from those in the thyroid, with a few exceptions (p = 0.4). No correlation of half-clearance times with parathyroid size, degree of early uptake, parathyroid hormone levels or histology could be established. Comparing adenomas to hyperplasia in respect to tetrofosmin retention, a statistically significant difference was observed (p = 0.005).. Technetium-99m-tetrofosmin is suitable for parathyroid imaging. The kinetic properties of this agent in parathyroid and thyroid tissues do not warrant differential washout protocols. The diagnostic impact of the observed difference in tetrofosmin kinetics between parathyroid adenomas and hyperplasia requires further investigation.

Topics: Adenoma; Female; Humans; Hyperparathyroidism, Secondary; Hyperplasia; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Subtraction Technique; Thallium Radioisotopes; Thyroid Gland; Time Factors

The purpose of this study was to determine the adsorption behavior of some widely used, commercially available 99mTc radiopharmaceuticals onto different types of plastic syringes.. Kits were reconstituted with 99mTc-pertechnetate diluted with 0.9% saline to produce maximum radioactive concentrations, as stated by the manufacturers. Aliquots of the solutions were transferred to four different brands of 2-ml syringes. The activity in the syringes was measured before and after injections or simulated injections. The amount adsorbed to the plastic syringe barrel and plunger before and after washout also was measured at different time intervals. Comparisons between products from different manufacturers were made for 99mTc succimer (DMSA) and 99mTc macroaggregated albumin (MAA).. Some 99mTC preparations undergo significant adsorption to plastic syringes. Adsorption differs considerably between products from different manufacturers. There was significantly higher residual activity in some types of syringes. In some cases the residual was as high as 40%-50% of the initial activity, and most of the adsorption occurred within 15 min of filling the syringe.. The data suggest that the extent of adsorption depends on pharmaceutical excipients in the kits and/or the type of syringe used. When inappropriate syringes are used, the reduction in the administered activity may result in poor-quality images. Therefore, the compatibility between radiopharmaceutical and syringe should be investigated under normal conditions of preparation and use every time a new brand of syringe or a new radiopharmaceutical comes into use in diagnostic nuclear medicine.

Topics: Adsorption; Disposable Equipment; Furans; Lysine; Materials Testing; Organophosphorus Compounds; Organotechnetium Compounds; Plastics; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Sulfhydryl Compounds; Surface Properties; Syringes; Technetium Compounds; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Dimercaptosuccinic Acid; Technetium Tc 99m Medronate; Technetium Tc 99m Sestamibi; Time Factors

Topics: Adenoma; Humans; Hyperparathyroidism; Methods; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Neoplasms; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Time Factors; Tomography, Emission-Computed, Single-Photon

Parathyroid scintigraphy with the new myocardial perfusion radiopharmaceutical 99mTc-tetrofosmin was compared with 99mTc-sestamibi scintigraphy using early and delayed imaging.. The two preparations were administered on different days to the same 16 patients suffering from primary hyperparathyroidism. Anterior view gamma camera planar imaging (10-min acquisition) was performed in the period between 5 min and 3 hr after administration of the radiopharmaceutical. For most of the patients, a pertechnetate image of the thyroid was available for eyeball comparison when reading the tetrofosmin and sestamibi images. Imaging results were compared with those from histopathological examination after surgery.. On early images, all the adenomas visualized with sestamibi were equally well seen with tetrofosmin and vice versa. In 6 of 11 scintigraphically detected neck adenomas, delayed imaging improved the adenoma visualization with sestamibi. In contrast, this differential washout was never seen with tetrofosmin. Histopathological examination of excised tissue specimens after neck exploration (15 patients) or thoracotomy (one patient) revealed a parathyroid adenoma in all 16 patients. Our 12 scintigraphic findings were true-positives, while the remaining four scintigraphies were false-negatives, giving a diagnostic sensitivity of 75% with both preparations. The mediastinal adenoma was detected in a patient with a history of two unsuccessful neck explorations and one unsuccessful thoracotomy.. Tetrofosmin has the same success rate as sestamibi for detection of parathyroid adenomas on scintigrams acquired immediately after injection. In contrast to sestamibi, delayed imaging has no diagnostic impact. Moreover, the thyroid/ parathyroid differential washout of sestamibi failed in 5 of 11 neck adenomas here detected, indicating that delayed sestamibi washout is an unreliable diagnostic criterion. Therefore, whether sestamibi or tetrofosmin is preferred for parathyroid scintigraphy, thyroid scintigraphy seems mandatory.

Topics: Adenoma; Aged; Female; Humans; Hyperparathyroidism; Male; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Thyroid Gland; Time Factors

Technetium-99m tetrofosmin, a lipophilic cationic complex molecule, was introduced for myocardial imaging. In some biodistribution studies it has also been reported to accumulate in the thyroid gland. Our objectives were to determine which thyroid nodules retain tetrofosmin and whether preoperative evaluation of malignancy is possible. Tetrofosmin scintigraphy was performed in 57 patients with a cold thyroid nodule on previously performed pertechnetate scintigraphy. All patients had undergone ultrasonography and sonographically guided fine-needle aspiration biopsy. The tetrofosmin scintigrams were obtained 5 min (early image) and 1 h (late image) after intravenous injection of 370 MBq. Only nodules that showed clear tracer retention after 1 h in comparison with retention at 5 min were classified as TETRO positive. Nodules without late retention were classified as TETRO negative. All patients underwent surgery and the histological results were compared with the results of tetrofosmin scintigraphy. Ten out of 11 patients with thyroid carcinoma (two pT1, three pT2, five pT4) were TETRO negative. One patient with papillary carcinoma (pT2) was TETRO positive. The mean nodular to thyroid tissue (N/T) ratio for the late scan was 1.0+/-0.20. There were 21 patients with thyroid adenomas (seven follicular, seven microfollicular and seven oxyphilic); 15 of these patients were TETRO positive and six TETRO negative. The mean N/T ratio for the late images was 1.34+/-0.41. All patients with degenerative goitre (24 cases) and the one patient with Hashimoto's disease were TETRO negative after 1 h and the N/T ratio was 0.92+/-0.12 on the late scan. Our results indicate that 99mTc-tetrofosmin scanning is of little value preoperatively in distinguishing thyroid carcinoma from other thyroid nodules. Tetrofosmin tends to demonstrate thyroid adenomas but does not have a routine role in the assessment of thyroid nodules.

Topics: Adenocarcinoma, Follicular; Adenoma; Carcinoma, Papillary; Diagnosis, Differential; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Neoplasms; Thyroid Nodule

The purpose of this investigation was to develop and evaluate a new and rapid miniaturized chromatography system that would accurately assess the radiochemical purity of 99mTc-tetrofosmin without the problems of solvent ratios and time requirements associated with the manufacturer's recommended procedure.. The migration of the radiochemical components of 99mTc-tetrofosmin was evaluated using various chromatography media with ethyl acetate as the solvent. After optimization of the miniaturized system, radiochemical purity assessments were performed simultaneously on 23 99mTc-tetrofosmin preparations using both recommended and miniaturized chromatography systems.. A miniaturized chromatography system consisting of Whatman 1 chromatography paper with ethyl acetate was developed for the radiochemical purity assessment of 99mTc-tetrofosmin. Radiochemical purity results for 99mTc-tetrofosmin preparations were similar with both recommended and miniaturized chromatography methods, with a mean difference of 1.5% +/- 1.2% (s.d.). Differences in radiochemical purity results between the two chromatography systems were less than 2% (20 of 23 evaluations) with most preparations.. Radiochemical purity results for 99mTc-tetrofosmin preparations were similar with both the manufacturer's recommended chromatography and miniaturized chromatography systems. The miniaturized chromatography system is easier to use, and the time required to perform radiochemical purity assessments is substantially reduced.

Topics: Acetates; Chromatography, Paper; Microchemistry; Micromanipulation; Miniaturization; Organophosphorus Compounds; Organotechnetium Compounds; Paper; Quality Control; Radiochemistry; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Solvents; Technetium; Time Factors

The aim of this study is to investigate the value of Tc-99m tetrofosmin (Tc-99m-TF) in conjunction with conventional Tc-99m-pertechnetate (Tc-99m-P) scintigraphy in the differentiation of malignant nodules from benign thyroid nodules. Forty-two patients [(32 females, 10 males; mean age 41 +/- 13 years; twenty-two multinodular goiter (MNG) patients with 58 nodules and 20 solitary thyroid nodules (STN)] were included in the study. Thyroid scintigraphy with Tc-99m-P and Tc-99m-TF, thyroid ultrasonography and fine needle aspiration cytology (FNAC) were performed. After i.v. injection of 370-550 MBq Tc-99m-TF, images were obtained at 15 minutes and evaluated semiquantitatively by using a five point (0-4) scoring system. Four patients with a hypoactive STN, and 1 patient with a hypoactive MNG was found to have thyroid malignancy by histopathological examination; 2 of these patients had false negative benign FNAC results. The tetrofosmin uptake score (TUS) was 2-3-3-3 and 3 in these 5 malignant nodules. Five hyperactive (hot or warm) STN with benign FNAC had a TUS of 2-3-3-3-3. All hypoactive (cold) MNG nodules with benign FNAC (n = 21) had TUS < or = 2. Our preliminary results suggest that follicular adenomas and thyroid cancers have higher tetrofosmin uptake than benign colloidal goiter nodules. Mitochondrial sequestration of tetrofosmin in benign or malignant follicular cells that proliferate more rapidly than normal follicular cells and/or hypervascularity may be responsible for this. The use of Tc-99m-TF in conjunction with Tc-99m-P thyroid scintigraphy will be helpful in the evaluation of patients with nodular goiter (NG). In patients with a STN, a hypoactive nodule with a high TUS has a higher probability of malignancy; whereas a hyperactive nodule with a high TUS is a follicular adenoma. In patients with MNG, a hypoactive nodule with a high TUS may be suggestive of malignancy despite a benign FNAC result. We think that further studies with Tc-99m-TF are required to confirm these results.

Topics: Adult; Biopsy, Needle; Diagnosis, Differential; Female; Goiter, Nodular; Humans; Hypothyroidism; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thyroid Gland; Thyroid Neoplasms

The aim of this study was to evaluate whether 99Tcm-tetrofosmin is a suitable agent for parathyroid scintigraphy. Ten patients with hyperparathyroidism and two normal subjects underwent parathyroid scintigraphy with both 99Tcm-tetrofosmin and 201TI. Thyroid image subtraction was performed with 99Tcm-pertechnetate. In the 10 patients with hyperparathyroidism, the scintigraphic results were compared with the surgical findings, which showed seven parathyroid adenomas, two parathyroid adenomas with a co-existing thyroid adenoma, and one thyroid carcinoma. Both 99Tcm-tetrofosmin and 201T1 revealed eight true-positive results, one false-negative results and one false-positive result, with concordance in 8 of 10 patients. The image quality with 99Tcm-tetrofosmin of both the raw and 99Tcm-pertechnetate subtracted images was always superior compared with that with 201T1. On the basis of the diagnostic results and the favourable dosimetric characteristics, we conclude that 99Tcm-tetrofosmin is a suitable agent for parathyroid scintigraphy.

Topics: Adenoma; Adult; Aged; False Negative Reactions; False Positive Reactions; Female; Humans; Hyperparathyroidism; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thyroid Neoplasms

The uptake of Tc-99m tetrofosmin (TF) is reported in a case of parathyroid adenoma. A 65-year-old woman was studied on different days with TF, Tc-99m sestamibi (MIBI) and Tl-201 chloride (Tl). TF and MIBI injections were preceded by oral administration of potassium perchlorate. Clear identification of the adenoma was observed in all scans. No further information was obtained using a subtraction technique with Tc-99m pertechnetate. Regarding the thyroid/parathyroid ratio, different kinetics between TF and MIBI appear to be demonstrated. In particular, thyroid washout was observed with MIBI but not with TF.

Topics: Adenoma; Aged; Female; Humans; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Subtraction Technique; Technetium Tc 99m Sestamibi; Thyroid Gland

Technetium-99m tetrofosmin is a lipophilic phosphine used for myocardial perfusion imaging. Biodistribution studies have shown significant thyroid uptake of tetrofosmin and preliminary reports have suggested that tetrofosmin imaging may be of value in patients with thyroid cancer. In this study, tetrofosmin whole-body scintigraphy was performed in 35 patients with evidence of thyroid diseases. All patients underwent laboratory evaluation of thyroid function as well as 99mTc pertechnetate scan, thallium-201 (n=16) 99mTc-methoxyisobutylisonitrile (MIBI) (n=19) whole-body studies. Thyroid images were semi-quantitatively analysed by a 4-point score: 0=no significant uptake; 1=uptake increased as compared to background activity, but inferior to normal thyroid tissue; 2=uptake equal to normal thyroid tissue; 3=uptake superior to normal thyroid tissue. Pathology examinations were obtained. A total of 41 thyroid nodules were detected, of which 15 were goitre nodules, 13 adenomas and 13 malignant lesions. In goitre nodules, concordant results of tetrofosmin and pertechnetate uptake (score 1 or 0) were observed in the majority of lesions (87%). In function adenomas (n=10), both tetrofosmin uptake and pertechnetate uptake were score 3. In non-function adenomas (n=3), tetrofosmin uptake was score 3, while pertechnetate uptake was score 0. In six malignant lesions, tetrofosmin uptake was score 3, while pertechnetate uptake was score 0; in the other seven lesions, where a prevalence of goitre abnormalities was observed, results of tetrofosmin and pertechnetate uptake were similar (score 0 or 1). In seven (70%) of the ten patients with malignant nodules, whole-body tetrofosmin images showed increased abnormal uptake in a total of 28 extra-thyroid tumour sites, as subsequently confirmed by other techniques. When tetrofosmin images were compared to 201Tl and 99mTc-MIBI scans, concordant results were observed in all cases. In conclusion, tetrofosmin imaging may be particularly useful to characterize and stage patients with malignant thyroid nodules; it shows similar results to thallium but provides better image quality. Comparable findings were observed between tetrofosmin and MIBI studies. Thus, tetrofosmin may be an alternative to thallium and MIBI in the aforementioned patients.

Topics: Adenoma; Female; Goiter, Nodular; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Sestamibi; Thallium Radioisotopes; Thyroid Neoplasms; Thyroid Nodule

Topics: Adenoma; Adult; Choristoma; Female; Humans; Lymphatic Diseases; Organophosphorus Compounds; Organotechnetium Compounds; Parathyroid Glands; Parathyroid Neoplasms; Radionuclide Imaging; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Thallium Radioisotopes; Thymus Gland