68Ga-triacetylfusarinine C and 68Ga-ferrioxamine E for Aspergillus infection imaging: uptake specificity in various microorganisms.

Purpose: (68)Ga-triacetylfusarinine C ((68)Ga-TAFC) and (68)Ga-ferrioxamine E ((68)Ga-FOXE) showed excellent targeting properties in Aspergillus fumigatus rat infection model. Here, we report on the comparison of specificity towards different microorganisms and human lung cancer cells (H1299).

Procedures: The in vitro uptake of (68)Ga-TAFC and (68)Ga-FOXE was studied in various fungal, bacterial and yeast cultures as well as in H1299 cells. The in vivo imaging was studied in fungal and bacterial rat infection and inflammation models.

Results: (68)Ga-TAFC and (68)Ga-FOXE showed rapid uptake in A. fumigatus cultures, significantly lower in other fungal species and almost no uptake in other microorganisms and H1299 cells, except for (68)Ga-FOXE in Staphylococcus aureus. (68)Ga-TAFC and (68)Ga-FOXE revealed rapid uptake in the lungs of A. fumigatus-infected rats, low accumulation in sterile inflammation and no uptake in bacterial abscess.

Conclusions: We have shown that (68)Ga-FOXE and (68)Ga-TAFC have high uptake in A. fumigatus both in vitro and in vivo. (68)Ga-TAFC showed higher specificity, while (68)Ga-FOXE showed higher sensitivity.