A pilot study on the pharmacokinetics, biodistribution and radiation dose of ^99mTc-RGD-BBN in healthy volunteers

Objectives ^99mTc-RGD-BBN is a new SPECT radiotracer for several tumor imaging with high uptake where integrin αvβ3 or gastrin releasing peptide receptor (GRPR) is highly expressed. This pilot study was to assess the pharmacokinetics,biodistribution and radiation dose of ^99mTc-RGD-BBN in the healthy volunteers.

Methods 10 healthy male volunteers were injected with ^99mTc-RGD-BBN (786.7±55.8 MBq, 19.1-24.2 mCi). Baseline measurements of vital signs, laboratory safety tests and 12-lead electrocardiogram were recorded before and after injection. Blood and urine sampling were collected and counts were obtained at various time points. Whole-body scans and ROIs of identified organs were used for visual analysis and estimating the radiation dosimetry.

Results No adverse reactions were found during the study. ^99mTc-RGD-BBN exhibited a rapid clearance from the blood with less than 45% of the initial dosage at 10 min after injection and gradual increasing radioactivity in urine with (52.9±6)% of original dose at 24h. The whole-body imaging showed high concentration in bladder and kidney. And the highest ^99mTc-RGD-BBN uptake was found in the kidneys (3.50E-02 mSv/MBq) because of its renal excretion pathway.

Conclusions ^99mTc-RGD-BBN exhibited properties of a nice pharmacokinetic and little radiation burden. It would be a safe and attractive SPECT agent in clinic applications.