¹⁷⁷Lu and ¹⁵³Sm are perspective radionuclides used in nuclear medicine. High-energy beta particles and the relative half-life of the radionuclides are used to achieve an effective palliative treatment of bone metastases. In this paper, the effect of the drug carrier EDTMP (i.e. ethylene diamine tetramethylene phosphonate) on the ionic form of ¹⁷⁷Lu and ¹⁵³Sm is presented. The absorbed doses of ¹⁷⁷Lu and ¹⁵³Sm in ionic form labeled with EDTMP in different organs and tissues are determined by IDAC-Dose 2.1 (Internal Dose Assessment by Computer) software and WinAct software which is used to calculate cumulative activity. ¹⁷⁷Lu and ¹⁵³Sm are lanthanide radionuclides which actively accumulate in the liver and bones when used in ionic form. In the case of labeling with EDTMP, the distribution and elimination of the drug occur according to the kinetics of the carrier, EDTMP. The use of an osteotropic complex (drugs attracted to and targeting bones) allows creating a large dose in the pathological areas and minimizes the damage of healthy organs and tissues. ¹⁷⁷Lu and 153Sm labeled with EDTMP decrease the liver dose absorption and increase the bone surface absorption for a more effective treatment and minimizing side effects. The effective dose per administered activity is 0.189 mGy/MBq for ¹⁷⁷Lu-ionic form, 0.232 mGy/MBq for ¹⁵³Sm-ionic form and 0.242 mGy/MBq for ¹⁷⁷Lu-EDTMP and 0.139 mGy/MBq for ¹⁵³sm-EDTMP.

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