Abstract |
Noninvasive imaging of iodide uptake via the sodium/iodide symporter (NIS) has received great interest for evaluation of thyroid cancer and reporter imaging of NIS-expressing viral therapies. In this study, we investigate 18F-labeled hexafluorophosphate (HFP or PF6-) as a high-affinity iodide analog for NIS imaging. 18F-HFP was synthesized by radiofluorination of phosphorus pentafluoride·N-methylpyrrolidine complex and evaluated in human NIS (hNIS)-expressing C6 glioma cells and a C6 glioma xenograft mouse model. 18F-HFP was obtained in radiochemical yield of 10 ± 5%, radiochemical purity of >96% and specific radioactivity of 604 ± 18 MBq/µmol. Specific uptake of 18F-HFP and high affinity of 19F-HFP were observed in hNIS+ C6-glioma cells. PET imaging showed robust uptake of 18F-HFP in NIS-expressing tissues (thyroid, stomach, and hNIS+ C6 glioma xenografts), and the uptake of 18F-HFP was blocked by NaClO4 pretreatment. Specific accumulation in hNIS-expressing xenograft (hNIS+) was observed relative to isogenic control tumor (hNIS-). Clearance of 18F-HFP was predominantly through renal excretion. The biodistribution showed consistent results with PET imaging. Minimal bone uptake was observed over 2 h period post-injection, indicating excellent in vivo stability of 18F-HFP. Although improvement in specific radioactivity is desirable, the results indicate that 18F-HFP is a promising candidate radiotracer for further evaluation for NIS imaging.
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Authors | Huailei Jiang, Aditya Bansal, Ribu Goyal, Kah-Whye Peng, Stephen J Russell, Timothy R DeGrado |
Journal | Bioorganic & medicinal chemistry
(Bioorg Med Chem)
Vol. 26
Issue 1
Pg. 225-231
(01 01 2018)
ISSN: 1464-3391 [Electronic] England |
PMID | 29198608
(Publication Type: Journal Article)
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Copyright | Copyright © 2017 Elsevier Ltd. All rights reserved. |
Chemical References |
- Fluorine Radioisotopes
- Radiopharmaceuticals
- Symporters
- sodium-iodide symporter
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Topics |
- Animals
- Dose-Response Relationship, Drug
- Female
- Fluorine Radioisotopes
- Glioma
(diagnostic imaging, metabolism)
- Humans
- Mice
- Mice, Nude
- Molecular Imaging
- Molecular Structure
- Neoplasms, Experimental
(diagnostic imaging, metabolism)
- Positron-Emission Tomography
- Radiopharmaceuticals
(chemical synthesis, chemistry, pharmacokinetics)
- Structure-Activity Relationship
- Symporters
(analysis, metabolism)
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