Characterization of the [(153)Sm]Sm-EDTMP pharmacokinetics and estimation of radiation absorbed dose on an individual basis.

[153Sm]Sm-EDTMP is a radiopharmaceutical used in palliation cares of bone metastases. The purpose of this study is to provide an explicit description of [153Sm]Sm-EDTMP pharmacokinetics, adopting a simple three-compartmental model with the analytical expressions calculating the rate constants and determining biodistribution parameters, like radiopharmaceutical uptake and clearance. This biokinetic model allowed us to calculate on an individual basis the dose to bone surface and to red bone marrow and to assess the degree of variability in dosimetric parameters using a fixed administered activity based only on patient weight.