Investigation of non-specific accumulation in PET imaging of 64Cu-labeled antibody

2015 Fiscal Year Final Research Report

• Project/Area Number: 25830107
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Tumor diagnostics
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Kanayama Yousuke 国立研究開発法人理化学研究所, ライフサイエンス技術基盤研究センター, 研究員 (60435641)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 抗体PET / 64Cu / がんイメージング / キレーター / 抗体フラグメント / 非特異的集積

Outline of Final Research Achievements

PET imaging of antibody drugs are expected to be highly useful for non-invasive diagnosis of target expression, selection of applicable patient, and treatment planning. To realize the antibody-based PET imaging, labeling method of positron emitting radiometal nuclide 64Cu has been investigated. In this study, we compared in vivo distribution of whole antibody, Fab, or F(ab’)2 fragments labeled with 64Cu using three different bifunctional chelator, DOTA-NHS-ester, SCN-Bn-NOTA, NODAGA-NHS-ester in the PET imaging of tumor-bearing mice.
As result, DOTA- or NODAGA-labeled Fab probes showed the increasing liver accumulation after the radioactivity in the heart (blood pool) was almost disappeared. The behavior of liver accumulation might be influenced by free 64Cu dissociated from chelators. On the contrary, NOTA-labeled probes showed lowest non-specific accumulations. Furthermore, it was indicated that linker structure was also able to affect the biodistribution.

Free Research Field

分子イメージング科学