Table 2.
Properties of four terbium radioisotopes [21, 25].
| Radio-isotope (T1/2) | Decay modes | Particle energy, Eα (MeV) | Particle energy, Eβavg (MeV) | Eγ, keV; (Iγ %) | Comment |
|---|---|---|---|---|---|
| 149Tb (4.12 h) | EC (82.3 %), α (17.7 %) | 3.97 MeV; Iα = 16.7% |
0.730 (Total Iβ+ = 7.1%) |
165.0 (26.4) | Path length in normal tissue = 25–28 μm; LET = 140–142 keV/μm, use in α-therapy and/or PET (Annihilation 511 keV= 14.2%) |
| 352.2 (29.4) | |||||
| 388.6 (18.4) | |||||
| 652.1 (16.2) | |||||
| 152Tb (17.5 h) | EC + β+ (100%) | _ | 1.140 (Total Iβ+ = 20.3%) |
271.1 (9.5), 344.3 (63.5), 586.3 (9.2), 778.9 (5.5) | PET (Annihilation 511 keV= 41%) |
| 155Tb (5.32 d) | EC (100 %) | _ | _ | 105.3 (25.1), 180.1 (7.5), 262.3 (5.3) | SPECT |
| 161Tb (6.89 d) | β− (100 %) | _ | 0.154 (Total Iβ−= 101%) |
25.6 (23.2), 48.9 (17.0), 74.6 (10.2) | β− and/or auger therapy |