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PubMedDate not supplied

Tc-99m tetrofosmin reverse perfusion pattern with ST segment depression after dipyridamole infusion in a patient with unstable angina and no evident coronary artery stenoses.

Reverse redistribution is a well-known pattern found when performing thallium myocardial scintigraphy, and it has been implicated as an indicator of myocardial ischemia. Much more rarely, when using technetium compounds, which do not redistribute, a similar pattern is noted after the second injection of the radiotracer. This pattern has been termed "reverse perfusion pattern," and its full implications are not yet clear and are still being investigated.

Angina, Unstable↗
PubMed2004

Comparison of subdermal and peritumoral injection techniques of lymphoscintigraphy to determine the sentinel lymph node in breast cancer.

PURPOSE: The purpose of this study was to evaluate 2 different injection techniques for lymphoscintigraphy to determine the axillary sentinel lymph node (SLN) in patients with breast cancer. METHODS: Thirty-six patients with early breast cancer were studied prospectively. Both peritumoral (PT) and subdermal (SD) injections were performed on each patient with Tc-99m rhenium sulfide colloid. PT injections were done 1 to 8 days before surgery and SD injections were done on the day of operation. An intraoperative gamma probe was used to explore the axillary SLNs prior to tumor excision and axillary dissection. All surgical specimens were evaluated histopathologically. RESULTS: In 19 of 36 patients, the same lymphatic drainage sites were observed with both techniques. Of these, 17 patients showed only axillary, 1 showed axillary and internal mammary (IM), and 1 showed axillary and subclavicular drainage sites. With PT injections 26 of 36 patients (72%), and with SD injections 33 of 36 patients (92%), showed axillary drainage and axillary SLNs. With PT injections 9 patients, and with SD injections only 2 patients, did not show any drainage site. During the operation with a gamma probe, axillary SLNs were excised in 35 patients (success rate, 97%). IM drainage was seen in 8 of 36 patients who underwent PT injections and in 3 of 36 with SD injections. CONCLUSION: The success rate was found to be higher with the SD injection technique than with PT injections to visualize the axillary SLN. To increase the visualization of both axillary and IM SLNs, it may be useful to perform lymphoscintigraphy with SD and PT injections together.

Axilla↗
PubMedDate not supplied

Investigating the capillary circulation of the foot with 99mTc-macroaggregated albumin: a prospective study in patients with diabetes and foot ulceration.

Macroaggregated albumin has been used to assess capillary circulation for over 20 years. The aim of the present study was to use 99mTc-macroaggregated albumin (99mTc-MAA) perfusion scanning to assess capillary circulation in feet with ischaemic ulcers in patients with diabetes, and relate the appearances to outcome. Twenty-three patients with diabetes presented with a total of 41 neuroischaemic foot ulcers. Perfusion scanning was performed by direct femoral artery injection of approximately 400,000 particles of 99mTc-MAA and imaging with a gamma camera. Patients were followed prospectively for 3 months. Scans were graded independently by a radiologist who was unaware of the site of the ulcers. Significant associations were detected between a radiologist's assessment of increased tissue perfusion and complete healing after 3 months (p = 0.047) and poor tissue perfusion on the image and failure to heal (p = 0.0005). This technique may be useful in deciding whether to persist with conservative treatment in patients with diabetes and foot ulceration.

Adult↗
PubMed1984

Quantitative reticuloendothelial function of liver and spleen in man.

A method for separate determinations of liver and spleen reticuloendothelial function, using a small-size 99Tcm -antimony sulphide colloid and gamma camera technique, is described. Several methods for achieving blood-background correction are examined, and it is shown that, by a three-compartment model, the use of a specific blood pool tracer can be dispensed with. Hepatic and splenic uptake of the colloid can be described by first order kinetics, and can be calculated to an error less than 5%. In a reference material (n = 13), hepatic and splenic clearance was 262 ml/min (100-412) and 22 ml/min (0-62), respectively. In cirrhosis (n = 7), hepatic clearance was decreased and splenic clearance increased. The results indicate that this method, which is well suited for clinical studies and which is based on a reasonable physiologic model, in cirrhosis of the liver demonstrates a decreased hepatic reticuloendothelial function with (compensatory?) increase in that of the spleen.

Antimony↗
PubMed1982

Osteomyelitis in the neonate. Clinical aspects and the role of radiography and scintigraphy in diagnosis and management.

Based on experience with 22 cases of neonatal osteomyelitis in 10 years, the authors suggest these patients can be divided into two groups depending on severity of disease. Premature infants requiring umbilical catheterization and severely ill full-term infants constitute a high-risk group; signs are more overt, multifocal infection and joint involvement more frequent, and severe skeletal deformities more common. The patients in the low-risk group had much milder disease but also presented more difficulty in diagnosis because of the vagueness of the presenting signs. Radiographic examination is essential for diagnosis and follow-up of osteomyelitis, particularly limb deformities. Bone scans should be reserved for situations in which the clinical and radiographic findings are equivocal.

Diphosphonates↗
PubMedDate not supplied

Breast cancer takes up 99mTc bombesin. A preliminary report.

BACKGROUND: Several tumors including lung, prostate, ovarian, colon, and exocrine pancreatic cancer show receptors for the amphibian neurotransmitter and growth factor bombesin (BN) and its mammalian counterparts gastrin-releasing peptide and neuromedin B. Also breast cancer has been reported to show such receptors: the presence of BN receptors in primary breast cancer has been demonstrated on cultured cells and by autoradiography on breast tissue samples. Authors who have studied BN receptors in breast cancer do not agree on their frequency in primary cancer, but indicate that 100% of metastatic breast cancers show such receptors. METHODS: We examined three primary breast cancer patients with 99mTc BN and 99mTc sestamibi one week before surgery. One of them showed axillary node invasion. The same acquisition technique was used for breast and chest imaging with both radiopharmaceuticals, whereas total body images were acquired only with 99mTc BN. Also the administered radioactivity was different: 20 mCi of 99mTc sestamibi and 5-8 mCi of 99mTc BN. Dynamic images were acquired for 20 mins after iv injection with the patient in ventral decubitus and the gamma camera positioned in a lateral view, as is generally done in Khakhali's prone scintimammography. Anterior chest images were acquired for 30 mins. Prone scintimammography was performed one hour after administration of both tracers. ROIs were drawn on tumors and surrounding breast with the same technique in order to calculate the tumor to breast ratio (T/B). In addition, total body scan was performed one hour and three hours after 99mTc BN administration. All three patients underwent breast conserving surgery with lymphadenectomy. Postoperative pathologic assessment showed the following T and N stages in the three patients: T1bN0, T1c-N0, and T1cN1. RESULTS: All three cancers were imaged with both tracers. The T/B of 99mTc BN was always higher than that of 99mTc sestamibi. Chest uptake was always much higher with 99mTc sestamibi than with 99mTc BN. Comparison between 99mTc BN and 99mTc sestamibi images gave other intriguing results: in the N1 patient both tracers clearly imaged the invaded node, but on the 99mTc BM image the primary tumor was larger than on the 99mTc sestamibi image and the node was smaller. It is known that 99mTc BN is not taken up by vessels and inflammatory tissue. The time activity curves of the two tracers were significantly different in all patients, with an increase in 99mTc BN uptake in the first three to five minutes, followed by a less sharp uprise of the curve, quite similar to a plateau. CONCLUSIONS: Our first impression is that 99mTc BN is a useful breast cancer seeking agent and very promising for lymph node staging.

Aged↗
PubMedDate not supplied

Phase I trial of technetium [Leu13] bombesin as cancer seeking agent: possible scintigraphic guide for surgery?

AIMS AND BACKGROUND: Bombesin-like neuropeptides work as neurotransmitters and growth factors at the same time. Several human cancers show overexpression of three receptors for mammalian counterparts of amphibia bombesins (ABNs), ie gastrin-releasing peptide (GRP), neuromedin B (NMB) and possibly another peptide. ABNs in turn are able to bind to mammalian and human receptors in vitro, and it is therefore interesting to study radioisotope-labeled bombesin (BN) and BN-like peptides as cancer seeking agents. METHODS AND STUDY DESIGN: Starting from the amino acid sequence of [Leu13] ABN, the Demokritos Institute has synthesized and labeled with technetium a new BN-like peptide that has the same biological characteristics as the amphibian peptide; changes were made only in the N-terminal part of the tetradecapeptide. After having obtained satisfactory results with 99mTc BN in a preclinical study, we started a phase I trial involving cancer patients as well as normal volunteers in Tomsk. Three normal volunteers, one patient with small cell lung cancer and one patient with primary prostate cancer were studied after iv injection of 185 MBq, corresponding to 0.7 micrograms of 99mTc BN. Dynamic images of the tumors were acquired for 20 mins, followed by SPET. Total body images were acquired in patients and normal volunteers 1 and 3 h after 99mTc BN acquisition. In addition, 99mTc sestamibi scintigraphy was performed in the patient with small cell lung carcinoma. RESULTS: No relevant side effects were observed. Both tumors were well visualized on early 1-2 mins images with planar as well as tomographic imaging. Total body images showed radioactivity in the liver, kidneys and thyroid gland. The stomach and spleen were ever imaged. Radioactivity was found in the urinary bladder 4 mins after injection in the patient with prostate cancer. Three-hour total body scans showed radioactivity in the duodenum. In the patient in whom also 99mTc sestamibi scintigraphy was performed, thyroid uptake was much higher with sestamibi than with 99mTc BN, whereas the uptake of small cell lung carcinoma was higher with 99mTc BN than with sestamibi. CONCLUSIONS: 99mTc BN is able to clearly image tumors with BN receptor overexpression. Our first impression is that in the future this radiopharmaceutical may serve as a cancer seeking agent and, due to its high tumoral uptake, also as a radiotracer for radioisotope-guided surgery.

Bombesin↗
PubMed2001

Study of the toxicological effect of mitomycin C in mice: alteration on the biodistribution of radiopharmaceuticals used for renal evaluations.

Mitomycin C (MMC) has been used as a component of many chemotherapeutic regimens and some toxic effects of this substance have been reported. As it has been reported that the toxicological effect of a drug can alter the biodistribution of radiopharmaceuticals and because patients on chemotherapeutic treatment can be submitted to a nuclear medicine procedure, we investigated whether MMC could affect the uptake of various technetium-99m (99mTc) radiopharmaceuticals used for renal evaluations. The purpose of this study was to suggest a model to evaluate the toxic effect of substances in specific organs. Three doses of MMC (0.45 mg) were administered to mice (N=15). One hour after the last dose, 99mTc radiopharmaceuticals, 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA), 99mTc-dimercaptosuccinic acid (99mTc-DMSA) or 99mTc-glucoheptonic acid (99mTc-GHA), with activity of 7.4 MBq, were also administered in the treated group and in the control group (N=15). After another 0.5 h, the animals were sacrificed. The organs were isolated, the 99mTc radiopharmaceutical uptake in the organs quantified in a well counter and the percentages of radioactivity (%ATI) calculated. The results have shown that: (i) with 99mTc-DTPA, the %ATI increased in the pancreas, ovary, uterus, stomach, kidney, spleen, thymus, heart, lung, liver, thyroid and bone; (ii) with 99mTc-DMSA, the %ATI decreased in all the organs except for the brain; and (iii) with 99mTc-GHA, the %ATI increased in the liver and decreased in the stomach, thymus, heart and thyroid. The effects of this chemotherapeutic drug on the biodistribution of these radiopharmaceuticals were statistically significant (Wilcoxon test, p<0.05) and could be explained by the metabolization and/or therapeutic action of MMC. Studies with other radiopharmaceuticals are in progress.

Animals↗
PubMed2001

Preoperative evaluation of sentinel lymph node status in melanoma by means of (99m)Tc-MIBI and lymphoscintigraphy: a case report.

Previous reports have shown that (99m)Tc-sestamibi (MIBI) could detect clinically occult metastatic melanoma lesions. This article reports on a patient with invasive melanoma of the right heel in whom the sentinel node status was preoperatively evaluated with this tracer. Although regional lymph nodes were clinically negative, (99m)Tc-MIBI scintigraphy showed focal increased tracer uptake in the right groin that corresponded to the location of 2 sentinel nodes visualized by lymphoscintigraphy with (99m)Tc-colloidal rhenium sulfide performed the same day. A gamma-probe was used intraoperatively to guide the excision of the sentinel nodes that were further classified as metastatic by histopathology. This double-technique approach is technically feasible and has the potential of selecting a group of patients who might benefit from a selective complete lymphadenectomy.

Humans↗
PubMedDate not supplied

Synthesis, radiolabelling and biological characteristics of a bombesin peptide analog as a tumor imaging agent.

BACKGROUND: Several human cancers, including small cell lung, prostate, breast, gastric, colon and pancreatic cancers, express receptors for bombesin-like peptides. Bombesin (BN) peptides that bind specifically to these receptors are useful for detection of bombesin receptor-expressing cancers in vivo. A new 99mTc-labelled-BN peptide for targeting bombesin receptor-expressing cancers was prepared and characterized. MATERIALS AND METHODS: MAG3-coupled BN peptide (MAG3-BN) was prepared by solid-phase synthesis and radiolabelled with 99mTc by an exchange method. In vitro cell binding assays were conducted on human breast cancer cell lines, MDA-MB-231 and MCF-7. In vivo biodistribution studies were performed in normal and nude mice bearing bombesin receptor-positive tumors. RESULTS: Radiolabelling of MAG3-BN with 99mTc produces a single radioactive species (> 95%). In vitro cell-binding indicated the affinity and specificity of 99mTc-MAG3-BN towards bombesin receptors. In vivo biodistribution in mice demonstrated that 99mTc-MAG3-BN cleared rapidly from the blood and most non-targeted tissues and was excreted mainly via the kidneys. Uptake in bombesin receptor-positive tissues and in the tumor was low to moderate. CONCLUSION: 99mTc-MAG3-BN displays good radiolabelling together with certain favorable biological characteristics and might be a useful peptide radiopharmaceutical in the detection of bombesin receptor-expressing cancers in vivo.

3T3 Cells↗
PubMed2006

[Evaluation of the therapeutic response: role of isotopic imaging].

In comparison with conventional imaging, nuclear medicine offers an original metabolic approach for the assessment of the therapeutic response. Gallium 67, thallium 201, technetium 99m-labeled sestamibi and diphosphonates can be performed for therapeutic response assessment in lymphoma, brain and breast tumours, sarcoma, or bone metastasis. PET-CT facilities are now easily available in France and are ready to provide a new and accurate tool in oncology, specially for therapeutic evaluation. The procedure consists in the injection of fluor-18-fluoro-déoxyglucose (18FDG), an analogue of glucose, followed by a PET then a CT acquisition for FDG uptake abnormalities location. Therapeutic response is assessed by a decrease of 18FDG tumoral uptake between two consecutive studies. Methodology and interpretation criteria have been recently defined in international guidelines. 18FDG-PET-CT seems to be a valuable tool for therapeutic response assessment of patients with Hodgkin or non Hodgkin malignant lymphoma. Promising preliminary results have been recently published for lung, gastro-intestinal and head and neck cancers. PET-CT could also be able to predict the therapeutic response after the first courses of chemotherapy, allowing an early treatment optimization. Finally, new PET agents pave the way for molecular imaging with promising results in gene therapy and targeted treatment in oncology.

Diphosphonates↗
PubMed1991

Quantitative evaluation of four 99Tcm colloids for bone marrow scintigraphy using single photon emission computed tomography.

Colloids used for bone marrow scintigraphy are also taken up in the liver and spleen. The liver activity in particular hampers interpretation of the study. In this study, four small-sized commercial colloids labelled with 99Tcm were compared for bone marrow uptake relative to the liver, spleen and background activity. Three human albumin colloids (Microlite, E.I. du Pont de Nemours & Co; Solco Nanocoll, Solco Nuclear; TCK-9, International CIS) and one antimony sulphide colloid (TechneScan Sb2S3, Mallinckrodt Diagnostics) were compared. The study was performed in patients routinely referred for liver/spleen scintigraphy who had a normal result. Each examination was carried out using single photon emission computed tomography. After correction for attenuation and scattering of photons, the activity of the bone marrow of the lumbar spine was related to the liver, spleen and background activity. The bone marrow/liver activity quotient of Solco Nanocoll and TCK-9 was almost twice the value for Microlite and TechneScan Sb2S3. The bone marrow/spleen quotient was almost four times higher and the bone marrow/background quotient almost twice as high for Solco Nanocoll as for the other three colloids, between which there were no significant differences.

Antimony↗
PubMed1989

[Diagnostic possibilities of static gamma-scintigraphy using 99mTc pyrophosphate and Tc 99m phosphate in children with glomerulo nephritis].

Children with nephrotic glomerulonephritis were examined for incorporation of 99mTc-pyrophosphate and 99mTc-phosphone. The relationship was discovered between the accumulation of the radiopharmaceutical drug and the sensitivity to glucocorticoids used in the pathogenetic treatment. Accumulation of the drug in the course of the treatment documents the presence of complete, partial remission or the disease activity. It is recommended that static gammascintigraphy should be carried out for early assessment of the efficacy of the treatment and its correction.

Adolescent↗
PubMed1989

Experience with 7,604 bone scintigraphies at time of operation for breast cancer 1977-1987.

From 1977 to 1987, 7,604 out of a total of 20,483 Danish breast cancer patients had a bone scintigraphy in order to exclude or localise osseous metastases. The scintigrams were performed and interpreted at 14 local hospitals. In 1979, standardised guidelines for interpretation were agreed upon. Until 1983, the scintigrams were described centrally, based on the local reports. From 1979, the frequency of positive bone scintigrams suggesting bone metastases stabilised at about 5% of the patients compared with 12 and 20% in 1977-78. The local take-over of description did not change the frequency. The frequency was also stable from 1979 when evaluated in age groups. With increasing age the frequency of positive scintigrams increased. The frequency of positive scintigrams was significantly lower in patients entering a protocol than in those not entering a protocol. The conclusion is that on a nation-wide basis it is possible to establish a stable, uniform interpretation of bone scintigrams after a two-year introduction period.

Adult↗
PubMed1989

Magnetic resonance imaging identifies early femoral head ischemic necrosis in patients receiving systemic glucocorticoid therapy.

Ischemic necrosis of bone, a frequent complication of glucocorticoid therapy, can result in disability due to bone collapse and destruction. Some investigators have suggested that core decompression of involved marrow benefits patients with early disease. As radiographs are normal in early disease, identification of patients has been dependent on nonspecific radionuclide imaging or more specific but invasive hemodynamic studies. In order to define a sensitive, noninvasive diagnostic tool, we compared magnetic resonance imaging (MRI) to 99mtechnetium diphosphonate and 99mtechnetium sulfur colloid scintigraphy in 10 consecutive glucocorticoid treated patients with suspected femoral head ischemic necrosis of bone but normal roentgenograms. MRI identified the ischemic necrosis (defined by characteristic radiographic progression or histology) in 13/13 femoral heads. Both scans together identified only 5/13 of the cases. Only 1/20 osteoarthritic femoral heads had MRI patterns similar to those seen in ischemic necrosis of bone. We conclude that MRI is a sensitive and relatively specific method to detect early femoral head ischemic necrosis of bone.

Adult↗
PubMed1987

Nuclear medicine applications for the diabetic foot.

Although no frequently described in the podiatric literature, nuclear medicine imaging may be of great assistance to the clinical podiatrist. This report reviews in detail the use of modern nuclear medicine approaches to the diagnosis and management of the diabetic foot. Nuclear medicine techniques are helpful in evaluating possible osteomyelitis, in determining appropriate amputation levels, and in predicting response to conservative ulcer management. Specific indications for bone, gallium, and perfusion imaging are described.

Arthropathy, Neurogenic↗