Ga-Labelled Carbon Nanoparticles for Ventilation PET/CT Imaging: Physical Properties Study and Comparison with Technegas®.

Purpose: The use of Ga-labelled carbon nanoparticles has been proposed for lung ventilation PET/CT imaging. However, no study has assessed the physical properties of Ga-labelled carbon nanoparticles. The aim of this study therefore was to evaluate the shape and size of Ga-labelled carbon nanoparticles, and to determine the composition of the aerosol, as opposed to Tc-labelled carbon nanoparticles aerosol.

Procedures: Tc- and Ga-labelled carbon nanoparticles, stable gallium carbon nanoparticles, 0.9 % NaCl and 0.1 N HCl-based carbon nanoparticles were produced using an unmodified Technegas® generator, following the usual technique used for clinical Technegas® production. The shape and size of particles were studied by transmission electron microscopy (TEM) after decay of the radioactive samples. The composition of the Zn- and Tc-labelled carbon nanoparticles aerosols was assessed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis after decay of the Ga- and Tc-labelled carbon nanoparticles, respectively.

Results: On TEM, all samples showed similar shape with hexagonally structured primary particles, agglomerated in clusters. The mean diameters of primary stable gallium carbon nanoparticles, Tc- and Zn-labelled carbon nanoparticles were 22.4 ± 10 nm, 20.9 ± 7.2 nm and 19.8 ± 11.7 nm, respectively.

Conclusion: Using Technegas® generator in the usual clinical way, Tc- and Ga-labelled carbon nanoparticles demonstrated similar shape and diameters in the same size range size. These results support the use of Ga-labelled carbon nanoparticles for the assessment of regional lung ventilation function with PET imaging.