Receptor imaging

Due to the clinical availability of Octreoscan , the first peptide-based receptor-imaging radiopharmaceutical, there has been much interest in the development of a complimentary therapeutic radiopharmaceutical.89... 

De Herder W. W., Reijs, A. E., de Swart, J. et al. Comparison of iodine-123 epidepride and iodine-123 IBZM for dopamine D2 receptor imaging in clinically non-functioning pituitary macroadenomas and macroprolactinomas. Eur. J. Nucl. Med. 26 46-50,1999. 

Selective 99mTc serotonin receptor imaging agents are of interest because of the involvement of this receptor in Alzheimer s disease as well as in depression. Complex 68 is a conjugate of 99mTc complex with... 

In the last decade, a large number of radiolabeled small biomolecules have been studied for their potential as radiopharmaceuticals for diagnosis and radiotherapy of various diseases. This review wiU focus on some fundamental aspects of receptor-based diagnostic radiopharmaceuticals, including radiopharmaceutical design, receptors and receptor imaging, choice of biomolecule, and modification of pharmacokinetics. 

In the last chapter receptor-based diagnostic radiopharmaceuticals are reviewed including considerations on drug design, on receptors, and on receptor imaging with the objective of modifying the pharmacokinetics of these agents. 

Lorraine Hood provided secretarial assistance Nicolette Perry, helpful comments and Margaret Piggott the receptor images on human brain. 

T.A. Podruchny, C. Connolly, A. Bokde, P. Herscovitch, W.C. Eckelman, D.A. Kiesewetter, T. Sunderland, R.E. Carson, R.M. Cohen, In vivo muscarinic 2 receptor imaging in cognitively normal young and older volunteers. Synapse... 

D. Neglia, G. Sambuceti, P. lozzo, A. L Abbate, H.W. Strauss, Myocardial metabolic and receptor imaging in idiopathic dilated cardiomyopathy, Eur. J. Nucl. Med. 29 (2002) 1403-1413. 

Ametamey, S.M. Westera, G. Gucker, P. SchdnbSchler, R. Honer, M. Spang, J.E. Schubiger, P.A. (2000) Functional brain receptor imaging with positron emission tomography. Chimia, 54, 622-6. 

Receptor imaging is still in its infancy and only a few papers dealing with this issue have been published in the recent literature. Several approaches have been proposed and are presented below. 

Ga-DOTATOC (150-210 MBq) or 68Ga-Bombesin (3 nmol) is usually injected into adult patients for receptor imaging (see Notes 2-4). The acquisition protocols are the same as in FDG. If different tracer studies are planned, the studies should be performed at different days to avoid background activity due to the decay of the injected isotope. 

Receptor-specific Small Molecules. Receptor imaging in nuclear medicine has been performed with small receptor-specific molecules radiolabeled with l (reactor produced). 

Aqueous hydrogen fluoride can be used for the acid decomposition of aromatic triazenes. Thus, 40% aqueous hydrogen fluoride is used in the preparation of fluorotamoxifen (2), a possible estrogen-receptor imaging agent, from triazene l.22... 

Secretin and calcium provocation tests have been used in the past to assist in the differential diagnosis of Z-E syn-drome. The secretin test proved the more useful but is little used now with improved computed tomography scanning and the use of somatostatin-receptor imaging using the somatostatin analog octreotide. ° ... 

The WDHA syndrome may be suspected in a patient producing large volumes (>1 liter/24 hours) of secretory diarrhea, with dehydration and hypokalemia. The diagnosis is confirmed by finding a high plasma VIP concentration and demonstration of the tumor by somatostatin-receptor imaging. 

Peptide receptor radionuclide therapy (PRRT) and peptide receptor imaging of malignant neoplasms have become a primary focus of interest in nuclear medicine. Neuroendocrine tumours frequently overexpress... 

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