Article Figures & Data
Figures
- FIGURE 1.
Decay of 225Ac via neptunium series.
- FIGURE 2.
Decay of 223Ra via actinium series.
- FIGURE 3.
Example of radiation safety precautions for patients receiving α-emitting therapies.
Tables
- TABLE 1.
Memorial Sloan Kettering Cancer Center α-Emitting Radionuclide Dose Escalation and Expansion Clinical Protocols
Radionuclide Activity administered (kBq kg−1) Total treatment cycles Period between cycles (wk) 223Ra Phase 1.1 50 1 NA Phase 1.2 100 1 NA Phase 1.3 200 1 NA Phase 2 50 6 4 Phase 3 50 6 4 NIST-adjusted Xofigo 55 6 4 225Ac Phase 1.1 18.5 1 NA Phase 1.2 37 1 NA Phase 1.3 74 1 NA Phase 1.4 148* 1 NA Phase 1.5 111 1 NA 227Th (in progress) Phase 1.1 1,500 kBq† 4 6 Phase 1.2 2,500 kBq† 4 6 Phase 1.3 3,500 kBq† 4 6 Phase 1.4 4,500 kB† 4 6 Phase 1.5 6,000 kBq† 2 6 Additional 25% increase 2 6 * Dose-limiting toxicity seen at phase 1.4.
↵†Patients receiving 227Th receive fixed dose values instead of weight-based doses.
NA = not applicable; NIST = National Institute of Standards and Technology.
- TABLE 2.
Restrictive Annual Limit on Intake Values for Select α-Emitting Radionuclides and Radionuclides in Common Medical Use
Radionuclide Decay mode Restrictive annual limit on intake (MBq) 18F β 1,850 99mTc IT 2,960 131I β 1.11 223Ra α 0.026 225Ac α 0.011 227Th α 0.011 - TABLE 3.
Removable Contamination Efficiencies and MDAs for Commonly Used Radiation Detection Equipment Integrated over 1-Minute Count Time for 225Ac
MDA Instrument Background (cpm) Efficiency (cpm/dpm) dpm Bq Portable survey meters α-probe (ZnS) 0 0.07 3 0.05 Thin window β-/γ-probe (GM) 33 0.18 147 2.47 Low-energy γ-probe (NaI) 234 0.06 1,128 18.82 Radiometric detectors Liquid scintillation counter 36 0.97 13 0.22 γ-counter 288 0.13 547 9.13 cpm = counts per minute; dpm = disintegrations per minute.
