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Author Eriksson, Jonas ♦ Åberg, Ola ♦ Selvaraju, Ram Kumar ♦ Antoni, Gunnar ♦ Johansson, Lars ♦ Eriksson, Olof
Source Paperity
Content type Text
Publisher Springer Berlin Heidelberg
File Format PDF ♦ HTM / HTML
Copyright Year ©2014
Subject Keyword Orthopedics ♦ Cardiology ♦ Oncology ♦ Nuclear medicine ♦ Imaging / radiology
Abstract Background The serotonin precursor 5-hydroxy-l-[β-11C]tryptophan ([11C]HTP) is in clinical use for localization of neuroendocrine tumors and has been suggested as a proxy marker for pancreatic islet cells. However, degradation by monoamine oxidase-A (MAO-A) reduces retention and the contrast to non-endocrine tissue. Methods A synthesis method was developed for 5-hydroxy-l-[β-11C2H]tryptophan ([11C]DHTP), an isotopologue of [11C]HTP, labeled with 11C and 2H at the β-position adjacent to the carbon involved in MAO-A decarboxylation. MAO-A-mediated degradation of [11C]DHTP was evaluated and compared to non-deuterated [11C]HTP. Results [11C]DHTP was synthesized with a radiochemical purity of >98%, radioactivity of 620 ± 190 MBq, and deuterium (2H or 2H2) incorporation at the β-position of 22% ±5%. Retention and resistance to MAO-A-mediated degradation of [11C]DHTP were increased in cells but not in non-human primate pancreas. Conclusions Partial deuteration of the β-position yields improved resistance to MAO-A-mediated degradation in vitro but not in vivo.
Learning Resource Type Article
Publisher Date 2014-11-30
e-ISSN 2191219X
Journal EJNMMI Research
Volume Number 4
Issue Number 1