Linked Life Data

18589296

Source:http://linkedlifedata.com/resource/pubmed/id/18589296

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-6-30
pubmed:abstractText
The use of (68)Ga-labeled peptides in diagnosis, dosimetry, therapy planning and follow-up of response to chemo- and radiotherapy requires accurate quantification of tracer binding characteristics in vivo, which may be influenced by the specific radioactivity (SRA) of the tracer. Systematic study of the complexation reaction of DOTA-D-Phe(1)-Tyr(3)-Octreotide (DOTATOC, where DOTA is the chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) with (67)Ga, (68)Ga, (69,71)Ga and in the presence of competing metal cations [Al(III), Fe(III), In(III)] was performed using conventional and microwave heating techniques and assessed by mass spectrometry. Saturation binding of (68)Ga-DOTATOC to Rhesus monkey brain slices was performed using frozen section autoradiography. High SRA was necessary in order to characterize the saturation binding of (68)Ga-DOTATOC to somatostatin receptors in Rhesus monkey brain sections. The complexation of Ga(III) with DOTATOC suggested more favorable formation compared to Fe(III) and In(III). The microwave heating mode might influence the selectivity of the complexation reaction, especially when comparing the behavior of Ga(III) and In(III). Al(III) was less critical with contamination and could be tolerated up to a concentration equal to that of the peptide bioconjugate. The SRA of (67)Ga-DOTATOC and (67)Ga-NODAGA-TATE (NODAGA-Tyr(3)-Octreotate, where NODAGA is 1,4,7-triazacyclononane-1-glutaric acid-4,7-diacetic acid) exceeded literature data by a factor of 7 and 5-15, respectively. High SRA was critical for providing sufficient contrast and accurate quantification of PET images. Microwave heating mode apart from the acceleration of the labeling reaction also improved the selectivity of the complexation reaction towards gallium. Fe(III) was shown to be the most critical competitor deteriorating the (68)Ga-labeling efficiency.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0969-8051
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
529-36
pubmed:meshHeading
pubmed-meshheading:18589296-Animals, pubmed-meshheading:18589296-Autoradiography, pubmed-meshheading:18589296-Aza Compounds, pubmed-meshheading:18589296-Cerebral Cortex, pubmed-meshheading:18589296-Chromatography, High Pressure Liquid, pubmed-meshheading:18589296-Drug Compounding, pubmed-meshheading:18589296-Gallium Radioisotopes, pubmed-meshheading:18589296-Isotope Labeling, pubmed-meshheading:18589296-Macaca mulatta, pubmed-meshheading:18589296-Metals, pubmed-meshheading:18589296-Microwaves, pubmed-meshheading:18589296-Octreotide, pubmed-meshheading:18589296-Peptides, pubmed-meshheading:18589296-Piperidines, pubmed-meshheading:18589296-Radiopharmaceuticals, pubmed-meshheading:18589296-Spectrometry, Mass, Electrospray Ionization, pubmed-meshheading:18589296-Spectrophotometry, Atomic, pubmed-meshheading:18589296-Thalamus
pubmed:year
2008
pubmed:articleTitle
The importance of high specific radioactivity in the performance of 68Ga-labeled peptide.
pubmed:affiliation
Uppsala Applied Science Lab, GEMS PET Systems, GE Healthcare, SE-752 28 Uppsala, Sweden. irina.velikyan@ge.com
pubmed:publicationType
Journal Article