Dynamics of formation of absorbed doses in the blood of laboratory animals from alpha-emitting radionuclides with successive decays

Since the beginning of XXI century, active research has begun on development fundamentally new radiopharmaceutical drugs based alpha-emitting maternal radionuclides for radionuclide therapy micro-tumors and metastases. The main difficulty in assessing absorbed doses internal irradiation such is to take into account radiation loads from all daughter sequential decay with alpha beta transformations. aim work develop a methodology calculating accumulated total blood laboratory animals successive decays within framework compartment modeling method. To test developed calculate dosimetric characteristics, free isotope Ac-225, injected as part its chloride Ac-225Cl3, osteotropic preparation Ac-225-KHEDP (monokalium salt hydroxyethylidendiphosphonic acid) labeled it were selected. Quantitative data bio-distribution Ac-225Cl3 body intact mice used identify necessary parameters. Calculations characteristics two Ac-225-labeled showed that values monotonically increase moment drug administration, reaching their limit equal by about 300 hours. Alpha-emitting parent make contribution doses. beta-emitting significantly less, therefore, they can be ignored when preliminary estimates are made. When using Ac-225-KHEDP, approximately 2.5 times less compared which explained higher clearance value Ac-225-KHEDP. results obtained indicate prospects further studies 225Ac-KHEDP possibility clinical application treatment skeletal