Table 2.
Metabolic pathways for T-cell imaging.
| Name/Target | Type | Tracer / substrate | Discussion | Active clinical trial | Ref |
|---|---|---|---|---|---|
| DNA synthesis | Deoxyribonucleotide | 1-(2′-deoxy-2′-[18F]fluoroarabinofuranosyl) cytosine | - Rapid probe catabolism by cytidine deaminase in humans - In general lower uptake in tumours as compared to [18F]FDG. |
n/a | 71, 72 |
| 2'-deoxy-2'-[18F]fluoro-9-β-⫐-arabinofuranosylguanine | - Predominantly via dGK | NCT03311672, NCT03142204, NCT03007719 | 75 | ||
| 3'-deoxy-3'-[18F]fluorothymidine | - In general lower uptake in tumours as compared to [18F]FDG. | n/a | 78, 79, 182 | ||
| 2-chloro-2′-deoxy-2′-[18F]fluoro-9-β-D-arabinofuranosyl-adenine | NCT03409419 | 61, 62 | |||
| Amino acid metabolism | Amino acid L-leucine analogue | trans-1'-amino-3'-[18F]fluorocyclobutanecarboxylic acid | - Rapid biological clearance in all tissue. | n/a | 76, 77, 183 |
| Glycolysis | Glucose analogue | 2'-deoxy-2'-[18F]fluoro-⫐-glucose | - (Very) low specificity for T-cells - No quantitative correlation with T-cell activation has been observed |
used in numerous trials for tumor response evaluation | 80-84 |