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ABSTRACT: A 69-year-old man presented with recurring drops in hemoglobin levels and suspected gastrointestinal bleeding. Endoscopy did not show a site of bleeding so further examinations became necessary. Scintigraphy and SPECT/CT with 99m TcO 4- -labeled red blood cells were performed without evidence of a hemorrhage. Based on an established protocol for splenic PET/CT, autologous erythrocytes can be labeled with 68 Ga-oxine and used as a tracer for the localization of active bleeding sites. In the patient, PET/CT with 68 Ga-oxine-labeled undamaged erythrocytes was performed successfully and revealed a hemorrhage of the gastric corpus that was confirmed and treated by endoscopy.
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Hemorragia Gastrointestinal , Tomografía Computarizada por Tomografía de Emisión de Positrones , Masculino , Humanos , Anciano , Hemorragia Gastrointestinal/diagnóstico por imagen , Cintigrafía , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Eritrocitos , TecnecioRESUMEN
INTRODUCTION: With the introduction of automated synthetization methods, the in-house production of several 68Ga-based tracers became feasible in hospital laboratories. We describe a possible standard operating procedure (SOP) for [68Ga]Ga-oxine-labeled heat-denaturated erythrocytes, which can be used for selective imaging in patients with splenic disorders. METHODS: Heat-denaturated erythrocytes were labeled with [68Ga]Ga-oxine, which was produced from 68Ga and 8-hydroxyquinoline on an automated synthesizer. The workflow was validated in a good manufacturing/good radiopharmaceutical practice (GMP/GRP) certified laboratory. A patient underwent [68Ga]Ga-oxine-erythrocyte PET/CT for differentiation of an intrapancreatic mass. RESULTS: [68Ga]Ga-oxine and [68Ga]Ga-oxine-labeled erythrocytes could be synthesized reproducibly and reliably. The products met GMP quality standards. The tracer showed high accumulation in the intrapancreatic mass, consistent with an accessory spleen. CONCLUSIONS: PET/CT imaging with [68Ga]Ga-oxine-labeled, heat-denaturated erythrocytes can be a backup method for the differentiation of functioning splenic tissue from tumors. An SOP for the production of the tracer in a clinical setting could be established.
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Oxiquinolina , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Bazo/diagnóstico por imagen , Radioisótopos de Galio , EritrocitosRESUMEN
Several scintigraphic techniques have been supplemented or replaced by PET/CT methods because of their superior sensitivity, high resolution, and absolute activity quantification capability. The purpose of this project was the development of a PET tracer for splenic imaging, its radiopharmaceutical validation, and its application in selected patients in whom unclear constellations of findings could not be resolved with established imaging methods. Heat-damaged red blood cells (RBCs) were labeled with [68Ga]gallium-oxine, which was produced from [68Ga]gallium and 8-Hydroxyquinoline (oxine) on an automated synthesizer. Ten patients underwent [68Ga]gallium-oxine-RBC-PET/CT for the classification of eleven unclear lesions (3 intra-, 8 extrapancreatic). [68Ga]gallium-oxine and [68Ga]gallium-oxine-labeled RBCs could be synthesized reproducibly and reliably. The products met GMP quality standards. The tracer showed high accumulation in splenic tissue. Of the 11 lesions evaluated by PET/CT, 3 were correctly classified as non-splenic, 6 as splenic, 1 as equivocal, and 1 lesion as a splenic hypoplasia. All lesions classified as non-splenic were malignant, and all lesions classified as splenic did not show malignant features during follow-up. PET/CT imaging of the spleen with [68Ga]gallium-oxine-labeled, heat-damaged RBCs is feasible and allowed differentiation of splenic from non-splenic tissues, and the diagnosis of splenic anomalies.
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Diferrocenyl thioketone reacts smoothly with (bisphosphane)Pt(0) complexes in toluene solution at room temperature yielding 1:1 adducts identified as ferrocenyl (Fc) functionalized platinathiiranes. Their structures were unambiguously confirmed by means of spectroscopic methods as well as by X-ray diffraction analysis. A unique, ferrocene-rich platinathiirane, bearing three Fc-units, was prepared starting with [bis(diphenylphosphino)ferrocene] Pt(0(η2-norbornene). For comparison, a similar platinathiirane with one Fc-unit was obtained from the reaction of the latter complex with thiobenzophenone. Quantum-chemical calculations were carried out to describe the bonding pattern and frontier molecular orbitals of the ferrocene-rich platinathiirane complexes. These calculations confirmed that the C=S bond loses its formally double-bond character upon complexation (bisphosphane)Pt(0). Cyclic voltammetry measurements were performed to characterize the obtained platinathiiranes in CH2Cl2 solutions. For comparison, the cyclic voltammogram for diferrocenyl thioketoneas a mixed-valent (FeII-FeIII) compound was also recorded and analyzed. The results point out to a diffusion controlled electrode process in case of differocenyl thioketone and mixed diffusion and adsorption controlled electrode process in the case of the studied platinathiiranes.
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Intracranial hypotension may lead to chronic, debilitating symptoms, and severe complications. The underlying CSF leak may be difficult to localize. To establish a new diagnostic option for the detection of CSF leaks, Cu-DOTA was developed as a tracer for PET imaging. PET/CT imaging was possible with high resolution and without complications. In one patient, the exact site of a dural tear was identified, enabling successful surgical treatment. PET cisternography with Cu-DOTA appears to be safe and able to locate a CSF leak. It has the potential to be a problem-solving modality in cases with inconclusive CT, MR, and/or scintigraphic findings.