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Isotopes
| Isotope | Dose rate (cGy/h) | T1/2 | Energy (MeV) | Half-value layers in tissue (mm) |
|---|---|---|---|---|
| Iodine-125 | 3–8 (Permanent) 40–70 (temporary) | 60.2 days | 0.028 (gamma rays) | 20.0 |
| Iridium-192 | 80–100 (LDR) 120–360 (HDR) | 74.2 days | 0.38 (gamma rays) | 60.0 |
| Cobalt-60 | >1,000 | 5.27 years | 1.25 (gamma rays) | 100.0 |
| Californium-252 | >350 | 2.64 years | 2.3 (neutrons) | |
| P-32a | 14.2 days | 1.7 (beta particles) | 0.8 | |
| Y-90a | 2.7 days | 2.3 (beta particles) | 1.1 |
aTypically used only for intracavitary BRT
