Linked Life Data

12677301

Source:http://linkedlifedata.com/resource/pubmed/id/12677301

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2003-5-27
pubmed:abstractText
DOTA-conjugated peptides, such as [DOTA(0),Tyr(3)]octreotide (DOTATOC) and [DOTA(0),Tyr(3)]octreotate (DOTA-tate), can be labelled with radionuclides such as (90)Y, (111)In and (177)Lu. These radiolabelled somatostatin analogues are used for peptide receptor radionuclide therapy (PRRT). Radioligands for PRRT require high specific activities. However, although these radionuclides are produced without addition of carrier, contaminants are introduced during production and as decay products. In this study, parameters influencing the kinetics of labelling of DOTA-peptides were investigated and conditions were optimised to obtain the highest achievable specific activity. The effects of contaminants were systematically investigated, concentration dependently, in a test model mimicking conditions for labelling with minimal molar excess of DOTA-peptides over radionuclide. Kinetics of labelling of DOTA-peptides were optimal at pH 4-4.5; pH <4 strongly slowed down the kinetics. Above pH 5, reaction kinetics varied owing to the formation of radionuclide hydroxides. Labelling with (90)Y and (177)Lu was completed after 20 min at 80 degrees C, while labelling with (111)In was completed after 30 min at 100 degrees C. The effects of contaminants were systematically categorised, e.g. Cd(2+) is the target and decay product of (111)In, and it was found to be a strong competitor with (111)In for incorporation in DOTA. In contrast, Zr(4+) and Hf(4+), decay products of (90)Y and (177)Lu, respectively, did not interfere with the incorporation of these radionuclides. The following conclusions are drawn: (a) DOTA-peptides can be radiolabelled at high specific activity; (b) reaction kinetics differ for each radionuclide; and (c) reactions can be hampered by contaminants, such as target material and decay products.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1619-7070
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
917-20
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Optimising conditions for radiolabelling of DOTA-peptides with 90Y, 111In and 177Lu at high specific activities.
pubmed:affiliation
Department of Nuclear Medicine, Erasmus MC Rotterdam, The Netherlands. w.a.p.breeman@erasmusmc.nl
pubmed:publicationType
Journal Article