Overview of Resin and Glass 90Y Radioembolization Products
| Characteristic | SIR-Spheres | TheraSphere |
| Composition | Resin with 90Y bound to surface | Glass permanently impregnated with 90Y |
| Size | 32.5 ± 5 μm | 20–30 μm |
| Number of spheres per vial | 40–80 million | 1.2–8 million |
| Specific activity at calibration | 50 Bq/sphere | 2500 Bq/sphere |
| Time after infusion when 90% of absorbed dose is delivered | ∼9 d | ∼9 d |
| Shelf life from time of calibration | 24 h | 12 d |
| Specific activity at treatment | 50–38.6* Bq/sphere | 2,500–111* Bq/sphere |
| Range of microsphere-number density per gray of average tumor-absorbed dose† | 413–535 mL-Gy−1 | 8.2–186 mL-Gy−1 |
| Range of microsphere-number density at… | ||
| 100-Gy average tumor-absorbed dose | 41,300–53,500 mL−1 | 820–18,600 mL−1 |
| 250-Gy average tumor-absorbed dose | 103,250–133,750 mL−1 | 2,050–46,500 mL−1 |