Positron Emission Tomography (PET), a noninvasive technique, is most
suitable for quantitative evaluation of in vivo tumor biology. Based on its metabolic
activity, the accumulation of F-18 fluorodeoxyglucose ([18F]FDG), a positron emitter
radionuclide, is most explored indicative of tumor features. Quantitative evaluation of
FDG uptake is frequently used for treatment monitoring following chemotherapy or
chemoradiotherapy. Several investigations showed that FDG PET, which measures
metabolic change, was a more sensitive marker than CT or MRI, which measures
morphological change. [18F]FDG is now frequently used to assess tumor metabolism as
well as to track the effectiveness of immunotherapy, which is a useful treatment for
several malignancies. With the use of in vivo whole-body CD8+ T cell and PD-L1
expression imaging, for instance, radiopharmaceuticals that are novel in nature offer
the rare chance to characterize the immunological tumor microenvironment (TME) and
more accurately forecast which patients may react to therapy. Longitudinal molecular
imaging may also aid in clarifying potent changes, especially in instances of resistance
that occurred during immunotherapy, and aid in guiding a more individualized
therapeutic strategy. To categorize, forecast, and track treatment response and
molecular dynamics in areas of therapeutic need, this review focuses on new and
existing uses of [18F]FDG for imaging.
Keywords: Checkpoint inhibitors, Immunotherapy, Positron emission tomography (PET), Tumor metabolism, [18F]FDG.
