The amount of energy deposited on any organ by ionising radiation termed absorbed dose, plays an important role in evaluating the risks associated with the administration of radiopharmaceuticals. In this research work, the absorbed dose received by human organs for 153Sm-TTHMP and 153Sm-PDTMP was evaluated based on biodistribution studies on the Syrian rats.

153Sm-TTHMP and 153Sm-PDTMP were successfully prepared with radiochemical purity of higher than 99%. The biodistribution of the complexes was investigated within the Syrian rats up to 48 hours post injection. The human absorbed dose of the complexes was estimated by the radiation dose assessment resource method.

The highest absorbed dose for 153Sm-TTHMP and 153Sm-PDTMP was observed in the trabecular bone with 1·085 and 1·826 mGy/MBq, respectively. The bone to other critical organ dose ratio for 153Sm-PDTMP is significantly greater than 153Sm-TTHMP. Also, the bone/red marrow dose ratio for these complexes is comparable with this ratio for 153Sm-EDTMP, as the most clinically used Sm-153 bone pain palliative radiopharmaceutical.

According to the considerable bone absorbed dose against the insignificant absorbed dose of non-target organs, these complexes can be used as potential bone pain palliative agents in clinical applications.