Pharmacokinetic properties of a new bone-seeking compound based on N,N,N',N'- ethylenediaminetetrakis(methylene phosphonic acid) labeled with 68GA in intact rats and rats with experimental model of bone callus

The objective of this work was the study of pharmacokinetic properties of N,N,N',N'- ethylenediaminetetrakis(methylene phosphonic acid) labeled with gallium-68 (68Ga-EDTMP) as a potential radiotracer for bone metastases imaging by positron emission tomography (PET). The investigation was carried out in both intact Wistar rats and rats with experimental model of bone callus. It was shown, that 68Ga-EDTMP had high bone affinity and reduced uptake in soft organs and tissues. The peak amount of activity in femur of intact rats reached 1,61%/g at 1 h after intravenous administration. The levels of activity in skeleton have been twice as high as those in blood already at 1 h after injection, and in muscle the amount of 68Ga-EDTMP was about 4-15 times lower as compared with bones. The highest uptake of activity in bone callus was 2,41%/g, and was almost twice the amount of 68Ga-EDTMP in intact femur. In conclusion, 68Ga-EDTMP can be a new promising PET radiotracer for bone metastases imaging.