Table 1.
Properties of radionuclides used in cysteine cathepsin-targeting radiotracers.
| Radio-nuclide | T1/2 | Decay mode (abundance)* | Particle/radiation energy (Emean in keV)** | Production (nuclear reaction) | Modality | Labeling chemistry |
|---|---|---|---|---|---|---|
| 3H | 12.32 a | β− | 5.7 | Reactor (6Li(n, α)) | In vitro | Covalent |
| 11C | 20.4 min | β+ (99.8%) | 386 | Cyclotron (14N(p, α)) | PET | Covalent, mostly electrophilic |
| 14C | 5730 a | β− | 49.5 | Reactor (14N(n, p)) | In vitro | Covalent |
| 18F | 109.8 min | β+ (97%) | 249 | Cyclotron (mostly 18O(p, n)) | PET | Covalent, mostly nucleophilic |
| 64Cu | 12.7 h | β+ (18%) | 278 | Cyclotron (64Zn(p, n)) | PET | Coordinative |
| 125I | 59.4 d | EC | 26.4 | Reactor (124Xe(n, γ)125Xe(EC)) | In vitro (SPECT) | Covalent, mostly electrophilic |
| 177Lu | 6.7 d | β−, γ | 133 (β−), 208 (γ) | Reactor (mostly 176Lu(n, γ)) | SPECT, therapy | Coordinative |
*
For clarity, only those nuclear transformations that are relevant for the imaging process are shown.
**
Data have been retrieved from the Brookhaven National Nuclear Data Center6.