Table 2. A summary for positron emission tomography tracers used for glioma.

Chemical type	Tracer	Target or intake mechanism	Note
18F: 18fluorine; 11C: 11carbon; FDG: fluorodeoxyglucose; LAT1: L-type amino acid transporter-1; MET: methyl-L-methionine; FET: O-(2-18F-fluoroethyl)-L-tyrosine; FDOPA: 3,4-dihydroxy-6-18F-fluoro-L-phenylalanine; FLT: 3′-deoxy-3′-18F-fluorothymidine; CHO: choline; FHO: fluorocholine; FMISO: fluoromisonidazole; ASCT2: alanine-serine-cysteine-2; ACE: acetate; FAC: fluoroacetate; FPIA: fluoropivalic acid; FPP(RGD)2: 2-fluoropropionyl-labeled PEGylated dimeric RGD peptide; BBB: blood-brain-barrier.
Glucose analogue	18F-FDG	Glucose	Demonstrate glucose metabolism; Poor tumor-to-background contrast
Amino-acid	11C-MET[62–63,65–66]	LAT1	Demonstrate amino-acid uptake; High sensitivity and specificity; Best and most studied tracers for glioma
	18F-FET[67–72]
	18F-FDOPA[73–76]
Thymidine analog	18F- FLT[77–82]	Thymidine kinase 1	Markers of cell proliferation; Cannot pass intact BBB
Choline	11C-CHO[84–86,88]	Choline transporter	Monitor membrane phospholipids; Cannot pass intact BBB
	18F-FHO[83,86–87]
Nitroimidazole	18F-FMISO[89–90]	Nitroreductase enzymes	Investigate intratumoural hypoxia; Haven't achieved clinical relevance
Amino acid	18F-fluciclovine [92,94–96]	LAT1 & ASCT2	Demonstrate amino-acid uptake; Transported by both LAT1 and ASCT2
Acetate	11C-ACE[99–100]	Acetate/acetyl CoA metabolism	Demonstrate the use of fatty acid
	14C-ACE[101]
	18F-FAC[102]
	18F-FPIA[103]
Peptide	18F-FPP(RGD)2[104–106]	αvβ3-integrin	Demonstrate angiogenesis