Abstract
Purpose: A reliable and routine process to introduce a new 18F-labeled dimeric RGD-peptide tracer ([ 18F]FPP(RGD) 2) for noninvasive imaging of α vβ 3 expression in tumors needed to be developed so the tracer could be evaluated for the first time in man. Clinical-grade [ 18F]FPP (RGD) 2 was screened in mouse prior to our first pilot study in human. Procedures: [ 18F]FPP(RGD) 2 was synthesized by coupling 4-nitrophenyl-2-[ 18F]fluoropropionate ([ 18F]NPE) with the dimeric RGD-peptide (PEG 3-c(RGDyK) 2). Imaging studies with [ 18F]FPP (RGD) 2 in normal mice and a healthy human volunteer were carried out using small animal and clinical PET scanners, respectively. Results: Through optimization of each radiosynthetic step, [ 18F]FPP(RGD) 2 was obtained with RCYs of 16.9±2.7% (n=8, EOB) and specific radioactivity of 114±72 GBq/μmol (3.08±1.95 Ci/μmol; n=8, EOB) after 170 min of radiosynthesis. In our mouse studies, high radioactivity uptake was only observed in the kidneys and bladder with the clinical-grade tracer. Favorable [ 18F]FPP (RGD) 2 biodistribution in human studies, with low background signal in the head, neck, and thorax, showed the potential applications of this RGD-peptide tracer for detecting and monitoring tumor growth and metastasis. Conclusions: A reliable, routine, and automated radiosynthesis of clinical-grade [ 18F]FPP(RGD) 2 was established. PET imaging in a healthy human volunteer illustrates that [ 18F]FPP(RGD) 2 possesses desirable pharmacokinetic properties for clinical noninvasive imaging of α vβ 3 expression. Further imaging studies using [ 18F]FPP(RGD) 2 in patient volunteers are now under active investigation.
Original language | English (US) |
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Pages (from-to) | 88-95 |
Number of pages | 8 |
Journal | Molecular Imaging and Biology |
Volume | 14 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2012 |
Externally published | Yes |
Keywords
- Automated radiosynthesis
- Clinical PET
- Integrins
- Oncology
- Peptides
- Radiopharmaceuticals
- Tumor angiogenesis
- [ F]FPP(RGD)
ASJC Scopus subject areas
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research