Published in:
Open Access
01-12-2021 | Positron Emission Tomography | Original research
[68Ga]Ga-4HMSA a promising new PET tracer for imaging inflammation
Authors:
Shigufa Kahn Ali, Samia Ait-Mohand, Véronique Dumulon-Perreault, Brigitte Guérin
Published in:
EJNMMI Research
|
Issue 1/2021
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Abstract
Background
Imaging diagnosis of inflammation has been challenging for many years. Inflammation imaging agents commonly used in nuclear medicine, such as [67Ga]Ga-citrate and 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) showed some limitations. The identification of a radiotracer with high specificity and low radiation dose is clinically important. With the commercialization of 68Ge/68Ga generators and the high 68Ga cyclotron production capacity, the study of 68Ga-based tracer for inflammation has increased and shown good potential. In the present work, we report the synthesis of 4HMSA, a new acyclic chelator, and its first investigation for 68Ga complexation and as a new positron emission tomography (PET) imaging agent of inflammation in comparison to [68Ga]Ga-citrate.
Results
The present experimental studies have shown that the novel [68Ga]Ga-4HMSA is stable allowing imaging of inflammation in a preclinical model of adjuvant- and pathogen-based inflammation involving intraplantar injection of complete Freund’s adjuvant (CFA). We also found that [68Ga]Ga-4HMSA displayed similar uptakes in the inflamed paw than [68Ga]Ga-citrate, which are superior compared to those of contralateral (non-injected) paws at days 1–3 from PET imaging. [68Ga]Ga-citrate accumulated in the upper body of the animal such as the liver, lungs and the heart, whereas the [68Ga]Ga-4HMSA revealed low uptakes in the majority of the organs and was cleared relatively rapidly from blood circulation through the kidneys and bladder.
Conclusion
The results highlight the potential of [68Ga]Ga-4HMSA as an interesting alternative to [68Ga]Ga-citrate for inflammation imaging by PET. The new PET tracer also offers additional advantages than [68Ga]Ga-citrate in term of dosimetry and lower overall background activity.