technetium-tc-99m-exametazime and Focal-Infection

Polyethyleneglycol (PEG) liposomes have been shown to be excellent vehicles for scintigraphic imaging of infection and inflammation in various experimental models. In this article we report on a series of patients with possible infectious and inflammatory disease in whom the performance of 99mTc-PEG liposomes was evaluated. The results of 99mTc-PEG liposome scintigraphy were directly compared with those of 111In-immunoglobulin G (IgG) scintigraphy.. Thirty-five patients (22 men, 13 women; mean age, 51 y; range, 20-76 y), suspected of having infectious or inflammatory disease, received 740 MBq 99mTc-PEG liposomes intravenously. Imaging was performed at 4 and 24 h after injection. Patients received 75 MBq 111In-IgG 24 h after administration of the liposomes. The scintigraphic results were compared and verified by culture, biopsy, surgery, and follow-up of at least 6 mo.. Of the 16 proven infections and inflammations, 15 were detected by 99mTc-PEG liposome scintigraphy: soft-tissue infection (n = 3), septic arthritis (n = 3), autoimmune polyarthritis (n = 2), infected hip prosthesis (n = 1), infected osteosynthesis (n = 1), spondylodiscitis (n = 1), infected aortic prosthesis (n = 1), colitis (n = 1), abdominal abscess (n = 1), and pneumonia (n = 1). 99mTc-PEG liposome and 111In-IgG scintigraphy both missed 1 case of endocarditis. In addition, an 111In-IgG scan of a patient with mild soft-tissue infection was false-negative. Concordantly false-positive scans were recorded from 2 patients, both with uninfected pseudarthrosis and focal signs of sterile inflammation. During liposomal administration, 1 patient experienced flushing and chest tightness, which rapidly disappeared after lowering the infusion rate. No other adverse events were observed.. This clinical evaluation of 99mTc-PEG liposomes shows that focal infection and inflammation can be adequately imaged with this new agent. The performance of 99mTc-PEG liposomes is at least as effective as that of 111In-IgG. With the simple and safe preparation and the physical and logistic advantages of a 99mTc label, 99mTc-PEG liposomes could be an attractive agent for infection or inflammation imaging.

Topics: Female; Focal Infection; Humans; Immunoglobulin G; Indium Radioisotopes; Inflammation; Leukocytes; Liposomes; Male; Middle Aged; Polyethylene Glycols; Prospective Studies; Radioimmunodetection; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime

The radionuclide investigation was performed 1-3 and 24 hours after injection of a radiopharm preparation and included the single photon emission computed tomography of the heart and scintigraphy of the whole body. Inflammation foci were found on the scans as hyperfixation foci of autoleukocytes labeled with 99mTc-HMPAO (hexamethylpropilene aminooxime). Four patients had abscesses with 0.8-1.5 cm diameter in projection of the aortal and mitral valves of the heart, and in 10 patients there were foci of inflammation and suppuration of extracardiac localization (in the area of the operation wound, anterior mediastinum, frontal sinuses, transverse colon, parietal pleura). The data obtained convincingly speak of high sensitivity and specificity of radionuclide diagnostic methods with the help of labeled elements of the whole blood in recognizing latent inflammatory and suppurative processes in cardiosurgical patients at the pre- and postoperative periods.

Topics: Adolescent; Adult; Aortic Valve; Endocarditis, Bacterial; Female; Focal Infection; Heart Valve Diseases; Heart Valve Prosthesis Implantation; Humans; Leukocytes; Male; Middle Aged; Mitral Valve; Radionuclide Imaging; Radiopharmaceuticals; Rheumatic Heart Disease; Surgical Wound Infection; Technetium Tc 99m Exametazime

To evaluate the clinical use of radionuclide-labeled white blood cell scintigraphy in the detection of focal sepsis.. Prospective clinical study.. A medical/surgical 12-bed intensive care unit (ICU) in a university hospital.. 26 trauma and surgical patients affected by sepsis of unknown origin were studied.. After the usual diagnostic approach, patients were submitted to a total body scan by using the patient's leukocytes labeled with technetium-99m (99m-Tc) HMPAO; three scintigraphy were performed within 20 h of tracer injection; the result of scan was completed with all clinical and instrumental data, including ultrasound (US) arnd computed tomography (CT), and the diagnostic efficacy was demonstrated for each patient on discharge from the ICU. The scan was able to detect 20 sites of infection; it was possible to rule out 11 suspected sites; only in two cases was the result considered to be false positive or false negative; in two cases the result was considered to be uncertain. These results show the high sensitivity (95%), specificity (91%) and accuracy (94%) of the method.. In ICU patients with sepsis, nuclear medicine can provide additional data, as the injection of radionuclide-labeled white blood cells (WBCs) allows the imaging of sites of infection. Analysis of our results suggests that scintigraphy with 99m-Tc-labeled WBCs can be considered a useful tool in the detection of the source of infection.

Topics: Adult; Aged; Critical Care; Critical Illness; Female; Focal Infection; Humans; Leukocytes; Male; Middle Aged; Multiple Trauma; Organotechnetium Compounds; Oximes; Postoperative Complications; Prospective Studies; Radionuclide Imaging; Reproducibility of Results; Sensitivity and Specificity; Sepsis; Survival Analysis; Technetium Tc 99m Exametazime

Topics: Focal Infection; Humans; Leukocytes; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Reproducibility of Results; Technetium Tc 99m Exametazime

We have recently developed a procedure to label liposomes containing reduced glutathione (GSH) with 99mTc using the lipophilic chelator, hexamethylpropyleneamine oxime (HMPAO). In the present study, we evaluated the use of 99mTc-liposomes to detect focal infection sites in rats. Rats were infected in the thigh by intramuscular injection with Staphylococcus aureus followed 24 hr later by an intravenous injection of 99mTc-liposomes, 67Ga-citrate, or 99mTc-human serum albumin (HSA). The animals were imaged under a gamma camera and subsequently killed at 4, 24 or 48 hr for tissue biodistribution studies. In contrast to infected rats receiving 67Ga-citrate or 99mTc-HSA, abscesses were prominently localized within 2 hr in rats after 99mTc-liposome injection, and continued to increase in activity up to 24 hr. Abscess-to-muscle ratios calculated from 24-hr biodistribution data obtained from tissue sampling were 35.3 +/- 7.6 for 99mTc-liposomes, 4.1 +/- 0.7 for 67Ga-citrate and 8.0 +/- 1.0 for 99mTc-HSA. These studies show the potential of using 99mTc-liposomes to localize infection.

Topics: Animals; Focal Infection; Liposomes; Male; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Staphylococcal Infections; Technetium Tc 99m Exametazime; Tissue Distribution

To evaluate the applicability of Tc-99m HMPAO leukocyte scintigraphy in the assessment of focal infections in children, we retrospectively analyzed 26 studies performed between 1988 and 1992. All patients (n = 25, age range 1 month-15 years) were severely ill and suspected to have invasive bacterial infection. In each case, whole body scintigraphy was performed 2-4 hours after injection of autologous labeled leukocytes. There were 8 true positive and 14 true negative cases; specificity was 88% and sensitivity 80%. The two false negative findings were observed in patients on immunosuppressive therapy; both had fungal infections. In one case, atypical non-specific bowel accumulation of the tracer was falsely interpreted as an abscess. The other false positive finding was hip accumulation in a patient who later turned out to have Mucha-Haberman disease; transient synovitis may explain the finding. Of the eight true positive cases, six had an invasive infection focus and two had an aseptic inflammatory process. Tc-99m HMPAO leukocyte scintigraphy is a valuable method in the assessment of focal inflammation in children, including infants.

Topics: Adolescent; Bacterial Infections; Child; Child, Preschool; Female; Focal Infection; Humans; Infant; Leukocytes; Male; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Retrospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime

To evaluate the usefulness of 99mTc-HMPAO-labeled leukocytes and 99mTc-labeled polyclonal human immunoglobulin G (Technescan HIG) in the diagnosis of focal purulent disease, 31 comparative scintigraphies were done in 30 patients with known or strongly suspected focal infection. Focal purulent disease was the final diagnosis in 19 patients. Technetium-99m-labeled leukocytes showed 16 true-positive, no false-positive, 11 true-negative and 3 false-negative findings. The corresponding figures for 99mTc-labeled HIG were 11, 2, 9 and 8. The sensitivity and specificity of imaging with labeled leukocytes were 84% and 100%, respectively, and with labeled HIG, 58% and 82%, respectively. The overall accuracy of the leukocyte scan was significantly better than that of the HIG scan (90% versus 67%, p < 0.001). Thus, if focal infection is suspected, scintigraphy with 99mTc-labeled leukocytes is the preferable method. No cases exhibited a better imaging result with 99mTc-HIG scintigraphy than with 99mTc-labeled leukocytes.

Topics: Female; Focal Infection; Humans; Immunoglobulin G; Inflammation; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Prospective Studies; Radioimmunodetection; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Topics: Arthritis, Infectious; Bacterial Infections; Focal Infection; Humans; Immunoglobulin G; Indium Radioisotopes; Leukocytes; Organotechnetium Compounds; Osteomyelitis; Oximes; Pentetic Acid; Radionuclide Imaging; Technetium Tc 99m Exametazime; Technetium Tc 99m Medronate