FET PET in Neuro-oncology and in Evaluation of Treatment Response

Morphologic magnetic resonance imaging is the mainstay in the diagnosis and follow-up of primary brain tumor. However, it has limited ability to differentiate tumor from edema, necrosis, or fibrosis. PET with (18)F-fluoro-ethyl-tyrosine (FET) is a promising and complementary diagnostic and prognostic tool to probe tumor biology in vivo. This article presents the tracer biology and uptake mechanism, the imaging protocol and quantitative image analysis, common pitfalls and variants, and the main indications for FET PET. Finally, a summary on what the referring physician needs to know about FET PET is presented.