Table 1.
Properties of compounds used in selective internal radiation therapy
| TheraSpheres | SIR-Spheres | QuiremSpheres | |
|---|---|---|---|
| Size, μm | 20–30 | 20–60 | 20–50 |
| Isotope | Yttrium-90 in glass matrix | Yttrium-90 adsorbed on resin surface | Holmium-166 on PLLA (poly-L-lactic acid) |
| Radiation emitted | beta (β) | beta (β) | beta (β) and low energy gamma (γ) |
| Physical half-life (T 1/2) | 64 hours | 64 hours | 26.8 hours |
| Activity per sphere, Bq | 2500 | 50 | 450 |
| Number of particles | ∼1–8×106 | ∼40–80×106 | 33×106 |
| Angiographic monitoring | No | Necessary (potential reflux) | Necessary (potential reflux) |