Comparison of Three Dimeric 18F-AlF-NOTA-RGD Tracers

Abstract

The rapid one-step radiolabeling strategy by the complexation of (18)F-aluminum fluoride with NOTA-peptide conjugates was successfully applied to synthesize three dimeric RGD peptides. Among the three probes developed, (18)F-AlF-NOTA-E[PEG4-c(RGDfk)]2 with relatively low liver uptake and high tumor accumulation appears to be a promising candidate for further translational research.

Comparing the Diagnostic Potential of 68Ga-Alfatide II and 18F-FDG in Differentiating Between Non–Small Cell Lung Cancer and Tuberculosis

“…Labeled by 18 F, 68 Ga, or 99m Tc, several RGD-based PET or SPECT tracers have been investigated in a series of landmark clinical trials (15,22,(24)(25)(26)(27)(28)(29). Recently, 18 F-NOTA-PRGD2 (denoted as alfatide) has shown to be promising in imaging properties and pharmacokinetics in preclinical or clinical studies (17)(18)(19). Further research in 18 F-Alfatide II (an upgraded version of alfatide) demonstrates great potential of this new tracer in detecting malignant bone and brain metastases (30,31).…”

“…Alfatide II [NOTA-E[PEG 4 -c(RGDfk)] 2 , an upgraded version of dimer RGD (Arg-Gly-Asp)-based tracer targeting the neovascular marker integrin a v b 3 , has been proven to be of lower liver uptake and higher tumor accumulation in mice (17). Clinical data are required to understand whether this new RGD-based angiogenesis tracer can highlight NSCLC lesions as well as differentiate lung TB from NSCLC.…”

Radiation dosimetry estimates of 18 F-alfatide II based on whole-body PET imaging of mice

“…The synthesis of the 18 F-alfatide II was based on the technique described in previous published papers (Guo et al, 2014;Kiesewetter et al, 2012). After comparison of three dimeric 18 F-AlF-NOTA-RGD Tracers (Guo et al, 2014), we used NOTA-PEG 4 -E[c(RGDfk) 2 ] as precursor.…”

“…The synthesis of the 18 F-alfatide II was based on the technique described in previous published papers (Guo et al, 2014;Kiesewetter et al, 2012). After comparison of three dimeric 18 F-AlF-NOTA-RGD Tracers (Guo et al, 2014), we used NOTA-PEG 4 -E[c(RGDfk) 2 ] as precursor. The radiochemical purity of the 18 F-alfatide II syntheses was above 98%, assessed by an analytical high performance liquid chromatography system equipped with an ultraviolet and radioactivity detector, and the radiochemical yield was more than 40% (decay corrected), with specific activity of 21 MBq/mmol.…”

“…It is widely accepted that imaging of tumor angiogenesis with RGD could be used not only for early detection of cancers, but also for monitoring treatment outcomes (Beer et al, 2011). In previous studies, (Guo et al, 2014) the newly synthesized 18 F-AlF-NOTA-E[PEG 4 -c(RGDfk)] 2 (denoted as 18 F-alfatide II) conjugates could withstand treatments during heating, solvent evaporation, pH adjustment, serum incubation, and in vivo circulation without detectable hydrolysis. More importantly, 18 F-alfatide II appeared to be superior to 18 F-alfatide I due to the lower liver uptake and higher tumor accumulation, which had been proved by in vivo imaging data (tumor uptake and tumor/non-tumor ratios).…”