Comparison of Somatostatin Receptor 2-Targeting PET Tracers in the Detection of Mouse Atherosclerotic Plaques
: Petteri Rinne, Sanna Hellberg, Max Kiugel, Jenni Virta, Xiang-Guo Li, Meeri Käkelä, Kerttuli Helariutta, Pauliina Luoto, Heidi Liljenbäck, Harri Hakovirta, Maria Gardberg, Anu J. Airaksinen, Juhani Knuuti, Antti Saraste, Anne Roivainen
Publisher: SPRINGER
: 2016
: Molecular Imaging and Biology
: 18
: 1
: 99
: 108
: 10
: 1536-1632
DOI: https://doi.org/10.1007/s11307-015-0873-1
PURPOSE:
Rupture-prone atherosclerotic plaques are characterized by accumulation of macrophages, which have shown to express somatostatin type 2 receptors. We aimed to investigate whether somatostatin receptor-targeting positron emission tomography (PET) tracers, [68Ga]DOTANOC, [18F]FDR-NOC, and [68Ga]DOTATATE, can detect inflamed atherosclerotic plaques.
PROCEDURES:
Atherosclerotic IGF-II/LDLR-/-ApoB100/100 mice were studied in vivo and ex vivo for tracer uptake into atherosclerotic plaques. Furthermore, [68Ga]DOTANOC and [68Ga]DOTATATE were compared in a head-to-head setting for in vivo PET/X-ray computed tomography (CT) imaging characteristics.
RESULTS:
Ex vivo uptake of [68Ga]DOTANOC and [68Ga]DOTATATE in the aorta was higher in atherosclerotic mice compared to control C57Bl/6N mice, while the aortic uptake of [18F]FDR-NOC showed no genotype difference. Unlike [18F]FDR-NOC, [68Ga]DOTANOC and [68Ga]DOTATATE showed preferential binding to atherosclerotic plaques with plaque-to-wall ratio of 1.7 ± 0.3 and 2.1 ± 0.5, respectively. However, the aortic uptake and aorta-to-blood ratio of [68Ga]DOTANOC were higher compared to [68Ga]DOTATATE in in vivo PET/CT imaging.
CONCLUSION:
Our results demonstrate superior applicability for [68Ga]DOTANOC and [68Ga]DOTATATE in the detection of atherosclerotic plaques compared to [18F]FDR-NOC.
