| 1. |
- Edgren, Maliha, et al.
(författare)
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[111In-DPTA-D-Phe1] - Octreotide Scintigraphy in the Management of Patients with Advanced Renal Cell Carcinoma
- 1999
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Ingår i: Cancer Biotherapy and Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1084-9785 .- 1557-8852. ; 14:1, s. 59-64
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Somatostatin receptor scintigraphy using the 111In-labelled somatostatin analogue octreotide (Octreoscan) was performed in 9 patients with metastatic renal cell carcinoma. In total 11 scintigraphies were performed. Positive tumor uptakes were observed in 9 patients. The results of the octreotide scans were correlated to diagnostic CT and/or X-ray images. Forty (59%) out of 68 known tumor localizations were visualized with the octreotide scan. A second scan following therapy was performed in two patients. These patients showed progressive disease despite treatment and also exhibited intensified uptakes at octreotide scintigraphy. One false positive lesion was observed in the 40 lesions visualized in scintigraphy.It was concluded that renal cell carcinoma expresses somatostatin receptors, as could be visualized with Octreoscan scintigraphy. The scintigraphic technique can be used as an instrument for in vivo characterization of the disease. The data could also form a basis for future investigations regarding the possible therapeutic effect of octreotide in the management of renal cell cancer.
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| 2. |
- Eriksson, Barbro, et al.
(författare)
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Positron emission tomography in neuroendocrine tumours
- 1999
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Ingår i: The Italian Journal of Gastroenterology and Hepatology. - 1125-8055. ; Suppl 2, s. S167-S171
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Tidskriftsartikel (refereegranskat)abstract
- Positron emission tomography is an in vivo tracer and imaging technique that utilizes short-lived positron emitting radionuclides (11C, 15O, 13N, 18F) with half-lives ranging between 2 min and 2 hours. These radionuclides are interesting from the labelling viewpoint since they are natural constituents of most biologically active compounds. The short half-life is an advantage with regard to the irradiation dose to the patient but it is also a limitation since it requires the production of these radionuclides in close vicinity to the positron emission tomography camera.
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| 3. |
- Bergström, Mats, et al.
(författare)
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PET with [11C]-Metomidate for the Visualization of Adrenocortical Tumors and Discrimination from Other Lesions
- 1999
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Ingår i: Clinical Positron Imaging. - 1095-0397 .- 1878-5751. ; 2:6, s. 339-
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Tidskriftsartikel (refereegranskat)abstract
- Purpose:The purpose of the study was to evaluate the potential role of PET with the adrenocortical-specific tracer 11C-metomidate in the characterization of incidentally found adrenal cortical lesions and in adrenocortical carcinomas.Methods:PET with 11C-metomidate was performed in 15 patients with unilateral adrenal mass confirmed by CT (incidentalomas) and in 9 additional patients with adrenocortical cancer. All incidentalomas subsequently underwent surgery, except 2 subjected to biopsy only. These lesions were histopathologically examined and diagnosed as adrenal cortical adenoma (n = 6; 3 nonfunctioning), adrenocortical carcinoma (n = 2) and nodular hyperplasia (n = 1). The remaining were non-cortical lesions including 1 pheochromocytoma, 1 myelolipoma, 2 adrenal cysts, and 2 metastases.Results:All lesions, except 1, with an adrenocortical origin were easily identified due to exceedingly high uptake of 11C-metomidate, whereas the non-cortical lesions showed very low uptake. The 1 false negative was a cancer that at surgery was found to be extensively necrotic. High uptake was also seen in normal adrenal glands. The tracer uptake kinetics indicated trapping of the tracer in the cortical lesions. For quantitative evaluation of tracer binding in individual lesions, the simple SUV concept was found to be equally accurate as more elaborate kinetic analyses.Conclusion:The patients presented and altogether over 40 PET investigations have demonstrated 11C-metomidate to be an attractive tracer for the characterization of adrenal masses with the ability to discriminate lesions of adrenal cortical origin from non-cortical lesions. Additionally the method allows the assessment of metastases from adrenocortical cancers, and the very high contrast has allowed partial whole-body examinations.
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| 4. |
- Carlsson, Jörgen, et al.
(författare)
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Conjugate chemistry and cellular processing of EGF-dextran
- 1999
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Ingår i: Acta Oncologica. - 0284-186X .- 1651-226X. ; 38:3, s. 313-321
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Tidskriftsartikel (refereegranskat)abstract
- Conjugates with specific binding to the epidermal growth factor receptor, EGFR, of interest for radionuclide based imaging and therapy were prepared using mouse epidermal growth factor, mEGF, and dextran. In one type of conjugate, mEGF was coupled to dextran by reductive amination in which the free amino group on the mEGF N-terminal reacted with the aldehyde group on the reductive end of dextran. The end-end coupled conjugate could be further activated by the cyanopyridinium agent CDAP, thereby introducing tyrosines to the dextran part. In the other type of conjugate, the cyanylating procedure using CDAP was applied, first to activate dextran and then allowing for the amino terminus of mEGF to randomly attach to the dextran. In the latter case, radionuclide-labelled tyrosines or glycines could be added in the same conjugation step. All types of mEGF-dextran conjugates had EGFR-specific binding since the binding could be displaced by an excess of non-radioactive mEGF. The conjugates were to a large extent internalized in the test cells and the associated radioactivity was retained intracellularly for different times depending on both the type of cells and conjugate applied. Different intracellular 'traffic routes' for the radionuclides are discussed as well as applications for both imaging and therapy.
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| 5. |
- Nilsson, Dag, et al.
(författare)
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Absorption of L-DOPA from the proximal small intestine studied in the rhesus monkey by positron emission tomography
- 1999
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Ingår i: European Journal of Pharmaceutical Sciences. - 0928-0987 .- 1879-0720. ; 7:3, s. 185-189
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Tidskriftsartikel (refereegranskat)abstract
- Positron emission tomography (PET) seems to be a valuable method for the understanding of intestinal absorption mechanisms, for simultaneous quantitation of absorption rate and distribution kinetics to the tissues of interest after oral drug delivery. PET was evaluated in three Rhesus monkeys for quantitation of the absorption rate from the gastrointestinal tract and the distribution kinetics into different organs. To obtain optimal standardized conditions for the measurement of absorption the drug was administered via a naso-duodenal catheter directly to the absorption site in the proximal small intestine. l-DOPA was used as study drug given in a suspension together with carbidopa and the radiomarker l-[beta-11C]DOPA. The l-DOPA suspension was given into the duodenum without and after administration of a suspension of six l-amino acids (120 mM) in order to investigate any interaction on the intestinal absorption and distribution of l-DOPA into the liver and brain tissue. Intestinal absorption was in general minor during the first study period and higher together with administered l-amino acids. The somewhat contradictory result with increased absorption when amino acids were present in the intestinal lumen, may be a consequence of increased intestinal motility initiated by the nutrient load.
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