Relative Biologic Effects of Low-Dose-Rate α-Emitting 227Th-Rituximab and β-Emitting 90Y-Tiuexetan-Ibritumomab Versus External Beam X-Radiation

Both at low doses and low-dose-rates, the 227Th-rituximab treatment was more effective per absorbed radiation dose unit than the two other treatments. The considerable effect at low doses suggests that the best way to administer low-dose-rates, α-emitting radioimmunoconjugates is via multiple injections.