technetium-tc-99m-tetrofosmin and thallium-chloride

This review aims at fostering comprehension and knowledge not only for expert physicians who can skillfully handle various techniques for tumor imaging but also for young practitioners in the field of nuclear medicine. As image processing software and hardware become smaller, faster and better, SPECT will adapt and incorporate these advances. A principal advantage of SPECT over PET is the more widespread availability of the equipment and lower cost for the introduction of the system in community-based facilities. Moreover, SPECT has become less dependent on a limited number of acknowledged experts for its interpretation owing to a variety of handy computer tools for imaging analyses. The increasing use of PET in tumor imaging is not necessarily proportional to the decline of SPECT. General physicians' attention to SPECT technology would also increase more by evoking their interest in "tracer imaging."

Topics: Animals; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Neoplasms; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Technology Assessment, Biomedical; Thallium; Tomography, Emission-Computed, Single-Photon

Scintimammography is a recently verified technique that will expand the use of nuclear medicine to a new group of patients in whom scintigraphic imaging has not been widely used. If performed correctly, and in certain groups of patients, it delivers a sensitivity as high as X-ray mammography or magnetic resonance imaging (MRI) in palpable tumours but with greater specificity. It is best used in patients in whom X-ray mammography, ultrasound and MRI prove non-diagnostic or unhelpful, particularly those women with dense breasts or who have had previous breast surgery. The mechanism of uptake of 99Tcm-MIBI in breast tissue is only partly understood and in itself may help in determining important aspects of tumour function, such as the response to cytotoxic chemotherapy. Other scintigraphic methods for imaging breast cancer may be able to look at other aspects of cancer function, for example blood supply, metabolic rate or the in vivo assessment of oestrogen or somatostatin receptor status. This in turn may be useful in planning treatment. Metastatic disease may best be monitored with 18F-FDG PET, which has a sensitivity greater than MRI but a similar specificity. Much furtner work will need to be done on the use of nuclear medicine in breast cancer, but the addition of unique functional information to the anatomical data from X-ray and MRI should benefit future patients' management.

Topics: Breast Neoplasms; Female; Fluorodeoxyglucose F18; Humans; Magnetic Resonance Imaging; Neoplasm Staging; Organophosphorus Compounds; Organotechnetium Compounds; Receptors, Estrogen; Receptors, Somatostatin; Reproducibility of Results; Technetium Tc 99m Sestamibi; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed

The aim of this study was to assess the influence of incremental nitroglycerin infusion (NTG+Inf) on the myocardial uptake of 99mTc-tetrofosmin (TF) in order to determine whether nitrates enhance the detection of viable myocardium with TF in patients with coronary artery disease (CAD) and left ventricular dysfunction. Fifty patients (39 males, 11 females; 54 +/- 11 years) with previous myocardial infarction and left ventricular dysfunction, who had been referred for coronary revascularization procedures, were studied. Myocardial single-photon emission tomography (SPET) images were obtained 1 h after injection of 750 MBq TF at baseline and after NTG+Inf, using a 2 day protocol. NTG+Inf was performed starting at 0.4 microg x kg(-1) x min(-1), with equal increments every 5 min up to 2 microg x kg(-1) x min(-1). Within 1 week of the TF study, rest-redistribution (R-RD) 201Tl SPET was performed after the injection of 111 MBq 201Tl. For each study, quantitative analysis was performed in 17 segments. Viability was defined as the presence of tracer uptake of > 50% of the peak activity on baseline studies or reversibility. There was significant correlation between quantitative regional RD 201Tl activity and TF activity after NTG+Inf (r = 0.90, P < 0.001). Of the 131 segments with severely reduced tracer uptake on resting TF images, 34 (26%) were reversible, showing increased tracer uptake after NTG+Inf (from 41%+/-7% to 57%+/-12% of peak activity; P < 0.001). All reversible segments after NTG+Inf had viability criteria on 201Tl studies. There was 95% concordance between TF with NTG+Inf and RD 201Tl imaging with regard to the presence of myocardial viability. We conclude that TF imaging with incremental NTG+Inf improves the detection of ischaemic but viable myocardium, correlating with the viability criteria observed on 201Tl studies. When the advantages of TF imaging are considered, rest TF imaging with NTG+Inf may be a practical diagnostic protocol in patients with CAD and left ventricular dysfunction who are being considered for revascularization.

Topics: Adult; Aged; Coronary Artery Disease; Female; Humans; Infusions, Intravenous; Male; Middle Aged; Myocardial Infarction; Myocardial Ischemia; Nitroglycerin; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Statistics as Topic; Thallium; Tomography, Emission-Computed, Single-Photon; Ventricular Dysfunction, Left

There are no large studies available to guide the selection of thallium (Tl), methoxyisobutylisonitrile (MIBI) or tetrofosmin (Tf) for myocardial perfusion imaging. Our objective was to compare the technical and clinical performance of the three in routine clinical practice. We randomised 2,560 patients to receive Tl, MIBI or Tf. A 1-day stress/rest protocol was used for MIBI and Tf. Tracer uptake was scored using a 17-segment model, quality and artefact scores were assigned, and ratios of heart (H), liver (L), subdiaphragmatic (S) and lung activity were measured. Mean quality scores (stress/rest) were Tl 2.13/2.16, MIBI 2.18/2.39, Tf 2.18/2.42 ( P=ns stress and <0.00001 rest). For attenuation artefact, Tl>MIBI=Tf ( P<0.05) and for low-count artefact Tl>MIBI>Tf ( P<0.001). For H/S, Tl>MIBI=Tf, for H/L Tl>MIBI=Tf, and for H/lung Tl

Topics: Adenosine; Artifacts; Coronary Disease; Cross-Sectional Studies; Dobutamine; Exercise Test; Heart; Heart Diseases; Humans; Myocardium; Organophosphorus Compounds; Organotechnetium Compounds; Quality Control; Radiography; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Technetium Tc 99m Sestamibi; Thallium; United Kingdom

Thallium 201, technetium 99m sestamibi (MIBI), and Tc-99m tetrofosmin differ in their myocardial uptake characteristics. This may make the technetium tracers less sensitive for detecting mild to moderate coronary stenosis.. We identified 163 patients with angiographic mild to moderate stenosis (50%-89%) and coexistent severe disease (88/163 patients) from a previous study of patients who received either thallium, MIBI, or tetrofosmin for myocardial perfusion scintigraphy. Summed segmental uptake scores were used to assess myocardial perfusion of territories supplied by the mildly to moderately stenotic vessels. Mean (+/- SD) summed stress uptake scores in the left anterior descending artery territory were 21.4 +/- 3.8, 21.6 +/- 4.2, and 22.1 +/- 2.3 for thallium, MIBI, and tetrofosmin, respectively (P = .7); mean summed difference uptake scores were 1.2 +/- 1.8, 1.1 +/- 1.9, and 1.0 +/- 1.1, respectively (P = .8). In the non-left anterior descending artery territory, mean summed stress uptake scores were 32.5 +/- 6.3, 34.0 +/- 6.3, and 34.5 +/- 4.7 for thallium, MIBI, and tetrofosmin, respectively (P = .4), whereas mean summed difference scores were 1.9 +/- 2.6, 1.7 +/- 2.2, and 1.7 +/- 2.3, respectively (P = .9).. There were no significant differences between the tracers for the summed uptake scores. This suggests that the 3 tracers are comparable in clinical practice for assessing the extent and severity of perfusion abnormalities arising from mild to moderate coronary artery stenosis, especially in the presence of coexistent severe disease.

Topics: Coronary Stenosis; Female; Humans; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Reproducibility of Results; Retrospective Studies; Sensitivity and Specificity; Severity of Illness Index; Technetium Tc 99m Sestamibi; Thallium

Topics: Barrett Esophagus; Duodenogastric Reflux; Esophagectomy; Gated Blood-Pool Imaging; Humans; Image Enhancement; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Subtraction Technique; Thallium

Topics: Biopsy, Needle; Carcinoma, Bronchogenic; Carcinoma, Squamous Cell; False Negative Reactions; Humans; Lung Neoplasms; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiography; Radiopharmaceuticals; Somatostatin; Thallium; Tomography, Emission-Computed, Single-Photon

Technetium-99m tetrofosmin has been used as a tumor-imaging agent in cases of lung cancer. The authors present a case showing a lung tumor that concentrated Tl-201 distinctly more than Tc-99m tetrofosmin during a dual-isotope cardiac examination. A brief review of the literature is provided and possible explanations for this difference in tracer uptake are discussed.

Topics: Adenocarcinoma, Bronchiolo-Alveolar; Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung; Humans; Lung Neoplasms; Male; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thallium

Topics: Breast Neoplasms, Male; Carcinoma, Ductal, Breast; Carcinoma, Lobular; Exercise Test; Heart; Humans; Male; Mammary Neoplasms, Animal; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium; Tomography, Emission-Computed, Single-Photon

The lower thorax and upper abdomen are visualized during cardiac acquisition of rest Tl-201 and stress Tc-99m tetrofosmin gated SPECT. Thus, abnormal Tl-201 localization in these areas and in organs such as parts of the lungs, liver, spleen, and kidneys can be observed, including rotating raw cine data.. Other than cardiac images, the authors retrospectively reviewed Tl-201 rotating (raw data) images of 235 patients. Abnormal findings in the lungs, liver, spleen, and kidneys were identified that correlated with the patients' clinical information; radiographic findings, including computed tomography and ultrasonography of the abdomen; other scintigraphic studies; and laboratory findings.. In 53 patients, 54 abnormalities were detected. Intrathoracic abnormalities included focal areas of increased uptake, one in the right lower lung and another in the right upper lung that confirmed lung cancer, in 2 patients; diffuse uptake in both lungs in 11 patients; photopenia in the lung bases, which had resulted from pleural effusions, in 3 patients; and abnormal right liver configuration caused by elevation of the right hemidiaphragm in 1 patient. Of the intra-abdominal abnormalities, 12 patients with splenomegaly were identified. Six patients had focal areas of increased uptake in the gastric area. Nonvisualization of one kidney resulted from a congenitally absent right kidney in 1 patient, from right nephrectomy in 1 patient, from end-stage renal disease in another, and from a lower position of the left or right kidneys in 5 patients. Small and decreased uptake of both kidneys resulted from end-stage renal disease in 1 patient. Small and decreased uptake of one kidney was noted in 1 patient with renal scarring, in 1 patient with a renal stone, in 3 patients with chronic pyelonephritis, and in 5 patients with renal cyst(s).. Discernible intrathoracic and intra-abdominal abnormalities using rotating raw cine data from imaging in three-dimensional displays include diffuse or focal pulmonary uptake, pleural effusion, elevation of a hemidiaphragm, splenomegaly, increased uptake in the gastric area, renal abnormalities including absent or small kidneys, end-stage renal disease, renal scarring, renal cyst(s), and lower position of a kidney. The incidental finding of such abnormalities may prompt further clinical investigation.

Topics: Abdomen; Cardiovascular Diseases; Digestive System Diseases; Gated Blood-Pool Imaging; Humans; Kidney Diseases; Lung Diseases; Motion Pictures; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Thallium; Tomography, X-Ray Computed; Ultrasonography

99mTc-labeled myocardial perfusion agents are excreted through the hepatobiliary system and can be used in the evaluation of the duodenogastric reflux that occurs during routine cardiac imaging. The resultant gastric activity can overlap the inferior wall of the left ventricle (LV) and can thus mimic reverse redistribution of the LV inferior wall on dual-isotope SPECT. We report a case of significant gastric activity, which leads to abnormally low LV ejection fraction and akinesis of the LV wall in addition to the appearance of reverse redistribution. This case report illustrates that care should be taken in the performance and interpretation of (99m)Tc-tetrofosmin SPECT in the presence of duodenal reflux. This condition could be mistaken for reverse redistribution in the inferior wall of the LV with concomitant underestimation of the LV and regional wall motion.

Topics: Aged; Diagnosis, Differential; Duodenogastric Reflux; Gated Blood-Pool Imaging; Heart; Humans; Male; Myocardial Contraction; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Stroke Volume; Thallium; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

According to improvement of SPECT system, ECG-gated SPECT with 201TlCl have been applied to the left ventricular volumetry. In this study 24 patients without ischemia demonstrated by stress (99mTc-TF) and rest (201TlCl) dual-isotope ECG-gated myocardial SPECT were enrolled. To evaluate left ventricular volumetry using 201Tl ECG-gated SPECT data, the left ventricular end diastolic volumes (EDV) were compared between Quantitative Gated SPECT (QGS) and Emory Cardiac Toolbox (ECT) as well as between dual-isotopes based on the same ECG-gated data. The EDV values with 99mTc data (EDVTc) using QGS were well correlated with those using ECT (r = 0.96, p < 0.0001). Both QGS and ECT demonstrated well correlation between EDVTc (r = 0.98, p < 0.0001) and the EDV value with 201Tl (EDVTl) (r = 0.93, p < 0.0001). However, QGS processing induced significantly lower EDVTl compared with EDVTc. In contrast, EDVTl were significantly higher than EDVTc in ECT performance. The QGS errors subtracting EDVTl from EDVTc were more evident according to the left ventricular volume increase. On the other hand, ECT error showed no tendency associated with the left ventricular volume. From these results, a careful strategy for selection of tracers and softwares should be necessary to assessment of quantitative values derived from ECG-gated SPECT data because of interaction with softwares, tracers, and subjects.

Topics: Adult; Aged; Algorithms; Electrocardiography; Female; Gated Blood-Pool Imaging; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Software; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left

A 34-year-old man with neurofibromatosis type 1 (von Recklinghausen's disease) was examined by 201TlCl and 99mTc-tetrofosmin scintigraphies. Hypervascularity was observed in the largest tumor of the right thigh. The tumor was also depicted on both scintigrams. Tumorectomy was performed and the pathologic examination revealed it to be a neurofibroma measuring 10 x 7 x 4 cm in size. These findings suggested that 201TlCl and 99mTc-tetrofosmin scintigraphies generally were unable to distinguish malignant from benign neurofibromas with certainty.

Topics: Adult; Humans; Male; Neurofibromatosis 1; Organophosphorus Compounds; Organotechnetium Compounds; Radionuclide Imaging; Radiopharmaceuticals; Thallium; Thallium Radioisotopes

The uptake and retention of single photon tracers in irradiated tumour cells was observed in an attempt at the early evaluation of the effect of radiation. T24 human bladder cancer cells were exposed to a single dose of 10 Gy or 20 Gy or a fractionated dose of 10 Gy (2 Gy for 5 days). The uptake of 201Tl chloride, 99Tcm-sestamibi and 99Tcm-tetrofosmin was observed by incubating in vitro for 60 min. The retention of the tracers was observed at 60 min after changing the incubation medium for a tracer-free medium. Uptake per culture well of all tracers in the cells exposed to 20 Gy declined as viable cell number decreased, but uptake per cell increased progressively. Uptake per cell of all tracers in the cells exposed to either a single dose or a fractionated dose of 10 Gy also increased, while a delay in growth was observed. The retention of these tracers decreased during this period and recovered thereafter. A binding assay with purified human leukocytes indicated that assessment with 99Tcm-sestamibi and 99Tcm-tetrofosmin is influenced by inflammatory cells. In conclusion, the effect of radiation may be underestimated if assessed by tracer uptake alone because of the increase in tracer uptake in viable irradiated cells. Observation of the retention of tracers may provide additional information.

Topics: Humans; In Vitro Techniques; Leukocytes; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Technetium Tc 99m Sestamibi; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tumor Cells, Cultured; Urinary Bladder Neoplasms

Thallium-201 is clinically used for the assessment of primary and recurrent brain tumors. The biologic properties of 201Tl that allow it to accumulate within the tumor cells render 201Tl useful in evaluating tumor malignancy, but its physical characteristics and nonroutine availability limits its use in some institutions, as compared to 99mTc-labeled compounds. The aim of this study was to assess the feasibility of using 99mTc-tetrofosmin for imaging brain tumors and to compare its uptake with that of 201Tl.. Twenty-six patients with 27 intracranial masses were studied with SPECT. In the first group of seven patients (Group A), the timing for optimal acquisition of the 99mTc-tetrofosmin scan was assessed. In the second group of 19 patients (Group B), two sequential 201Tl (74-148 MBq intravenous) and 99mTc-tetrofosmin (740-925 MBq intravenous) studies were performed 20 min after tracer injection and compared.. In Group A, no significant difference in the tumor-to-background (T/B) ratio among the 20-, 40- and 120-min postinjection studies was observed. In Group B, the quality of reconstructed images with 99mTc-tetrofosmin, judged visually, was superior to that of 201Tl in 47% of all studies and was comparable in the remaining 53%. A significant relationship between 201Tl and 99mTc-tetrofosmin T/B ratio (r = 0.75, p < 0.01) was found. The T/B ratio of 99mTc-tetrofosmin was significantly higher than that of 201Tl (23.3 +/- 21.5 compared to 6.1 +/- 2.9, p < 0.005).. Technetium-99m-tetrofosmin is a suitable radiotracer for the imaging of intracranial lesions with SPECT. Moreover, a better definition of tumor margins and a higher contrast between neoplastic and normal brain tissue can be achieved.

Topics: Brain Neoplasms; Feasibility Studies; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Organophosphorus Compounds; Organotechnetium Compounds; Radiopharmaceuticals; Thallium; Thallium Radioisotopes; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed