Table 1.
Unique differences between bone-seeking radionuclides
| Beta-emitter | Alpha-emitter | Study drug (117 m-Sn-DTPA) | |
|---|---|---|---|
| Characteristics | High-energy, high-speed electron (variable energy and penetrance) | Highly localized (short range), high-linear energy transfer | Low energy conversion electron emitter (monoenergetic and finite penetrance) |
| Range in tissue (µm) | 50–5000 | 40–90 | 300 |
| Bio-distribution |
-Bone uptake 52% (41–57%) -Rapid disappearance from soft tissue -Excrete through small bowel |
-Bone uptake 82% and resides in cortical bone rather than adjacent bone marrow cavity -Rapid disappearance from soft tissue -Excrete through kidney |
|
| Side effects | Greater bone marrow toxicity | Moderate bone marrow toxicity | Least bone marrow toxicity |
| Decay | Beta decay | Gamma | Gamma (159 keV) |
| Half-life | 1.9 days (153Sam), 14.3 days (32 P) and 50.5 days (89Sr) | 11.4 days | 14 days |