Imaging the Tumor Antioxidant Response with [ 18 F]FSPG PET.

(4S)-4-(3-[ ¹⁸ F]Fluoropropyl)-L-glutamic acid ([ ¹⁸ F]FSPG) is a flourine-18 labeled glutamate analog that enables the noninvasive in vivo imaging of cellular redox status. [ ¹⁸ F]FSPG is transported across the cell membrane by the cystine/glutamate antiporter, system x _c ^- , whose expression is upregulated in multiple cancer types. The requirement of cystine for the biosynthesis of glutathione, a major antioxidant, connects [ ¹⁸ F]FSPG tissue retention to the intracellular redox response via system x _c ^- activity. We herein describe the use of [ ¹⁸ F]FSPG positron emission tomography (PET) to image the tumor antioxidant response and highlight key methodological considerations.
(© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)