Table 1. Radioisotope-Based PSMA-Targeted Tracers for Image-Guided Surgery.
| compound | receptor affinity (competitor) | tumor-to-background (time point, cell line, background tissue) | kidney-to-tumor (time point, cell line) | injected dose | biodistribution; time point | clearance pathway (time point, uptake clearance organs) | half-life | lipophilicity | plasma protein binding | optimized for entrance funnel? | imaging label | imaging signature (s) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 68Ga-PSMA-1178 | IC50 = 7.5 ± 2.2 (2-PMPA) | 8b (1 h, LNCaP, muscle) | 18.1 (1 h, LNCaP) | 0.1–0.2 (10–20 MBq/nmol) | Yes; 1 h | Renal (1 h, kidneys 139.4 ± 21.4%ID/g, liver 0.87 ± 0.05% ID/g) | t1/2, rad = 1.1 h | LogP = −3.15a | Data not provided | Yes | HBED-CC, 68Ga | β (Emaxβ+ = 1899 keV), γ (Eγ = 511 keV), Cerenkov (>250 nm) |
| 111In-PSMA I&T48 | IC50 = 7.5 ± 1.5 nM ((125I-BA)KuE) | 43 ± 6 (1 h, LNCaP, muscle) | 23.8 (1 h, LNCaP) | 0.2 nmol (7 MBq/nmol) | Yes; 1 h | Renal (1 h, kidneys, 191 ± 24%ID/g, liver 0.26 ± 0.04%ID/g) | t1/2, rad = 67 h | LogP = −4.5 | 83%93 | Yes | DOTAGA, 111In | γ (Eγ = 171.3, 245.4 keV) |
| 99mTc-PSMA I&S93 | IC50 = 39.7 ± 1.2 nM((125I-BA)KuE) | 21 (1 h, LNCaP, muscle) | 22.5 (1 h, LNCaP) | 0.1 nmol (30–40 MBq/nmol) | Yes; 1 h, 3 h, 5 h, 12 h, 16 h, 21 h | Renal (1 h, kidneys 186 ± 23%ID/g, liver 1.58 ± 0.24%ID/g) | t1/2, rad = 6.5 h | LogP = −3.0 | 94% | Yes | mas3,99mTc | γ (Eγ = 140.5 keV) |
a
Values were calculated by using ChemAxon’s Chemicalize plugin.
b
Estimated from graph.