Evaluation of 2-deoxy-2-[¹⁸F]fluoro glucaric acid (FGA) as a potential PET tracer for tumor necrosis

In this study, [¹⁸F]FGA was obtained by a one-step oxidation of [¹⁸F]FDG using sodium hypochlorite. The conversion from [¹⁸F]FDG to [¹⁸F]FGA was confirmed by HPLC to be over 95% using the optimal condition. A549-luciferase NSCLC xenografted mice was used for in vivo PET imaging. Prior to either saline or cisplatin treatment, there was no significant difference on tumor uptake of [¹⁸F]FGA in all mice, with an average uptake of (0.21 ± 0.16) %ID/g. After treatment, tumor uptake of [¹⁸F]FGA was not changed significantly for saline-treated mice, whereas the tumor uptake of [¹⁸F]FGA drastically increased for cisplatin-treated mice, with an average uptake of (1.63 ± 0.16) %ID/g. The ratio of tumor uptake between cisplatin-treated vs. saline-treated mice was 7.8 ± 0.2 within one week of treatment. PET imaging results were consistent with ex vivo biodistribution data. BLI showed significant light intensity suppression after treatment, indicating necrosis. Our data indicate that [¹⁸F]FGA uptake was related to tumor necrosis. [¹⁸F]FGA PET/CT imaging might be a useful tool to monitor treatment response to chemotherapy by imaging tumor necrosis.