Selecting TARE particle
- Stable Y89 is bombardment with neutron leads to formation of Y90
- Chemical separation from parent isotope Strontium 90
- Yttrium 90 decays to Zirconium 90
- Near – pure emission of β particle (free electron emission)
Small portion – decay through pair production (PET imaging) - Average energy – 933.7 KeV
- Half Life – 64.2 hrs (2.67 days)
- Path travelled
2.5 mm – (2/3rd particles),
5mm – 90% particles
11 mm – Maximum distance upto which particle were detected
TARE PARTICLES:
| Glass-Sphere | Resin-Sphere | |
|---|---|---|
| Material | Spherodized aluminum and silicon dioxide glass containing Yttrium-89 (Y89) subjected to neutron bombardment which activates Y89 into Y90 | Biocompatible polymer coated with a cross-link cation exchange polystyrene resin ionically bound to Y90 |
| Leech effect (Bone deposition and Myelosuppression) | Y90 is embedded in the glass matrix (minimal) | Y90 immobilized with phosphate salts, therefore Don’t use Ionic contrast or normal saline (only 0.01%-0.4% of released particles can cause myelosuppression) |
| Specific Gravity | 3.6 g/dl (settle down) (More force than native blood flow maybe required to inject the particles and causes diversion from low resistance tumor vessel to high resistance non-tumor vessel, Basciano) | 1.6 g/dl (similar to blood therefore more uniform distribution) (more penetration seen in surrogate hepatic artery system, Jernigan) |
| Size | 15-35 um (95% particles) | 29-35 um and intimately bound |
| Activity Vial Not Updated | 3 ,5, 7, 10,15, 20 GBq 1.2 , 2 , 2.8, 4, 6, 8 million microsphere (respectively) Extended shelf life present (upto 12 days) vial cannot split and so entire vial must be injected | 3 Gbq +/- 10% (at 6 PM the day following delivery to the institution and can be used up to 24 hours after calibration) 40-80 million microspheres (2 batches - 14 vials and 5 vials) |
| Specific Activity & Embolic Effect | High-Specific activity (2500Bq/particle) Mild radioembolic effect | Low-Specific activity (75 Bq/particle and 37.5 Bq/particle) Moderate/High radio embolic effect |
| PVT (minimal embolic effect) | Indicated | May result in embolic occlusion of the parent vessel (Dose fractioning needed if used) |