Pharmacokinetics and radiation dosimetry of Tc-99m-3PRGD(2) in healthy individuals: A pilot study

Te-99m-3PRGD(2) is a new SPECT radiotracer for several tumor imaging with high uptake where integrin alpha(v)beta(3) is highly expressed. This pilot study was to assess the safety, biodistribution and radiation dosimetry of Tc-99m-3PRGD(2) in healthy volunteers. The 10 healthy male volunteers were injected with Tc-99m-3PRGD(2) (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 samples were collected and radiation 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. No adverse reactions were found during the study. Tc-99m-3PRGD(2) 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 1440 mm. The whole-body imaging showed high radioactive accumulation in bladder. And the highest Tc-99m-3PRGD(2) uptake was found in the kidneys (3.50x10(-2) mSv/MBq). The Tc-99m-3PRGD(2) exhibited good pharmacokinetic properties and little radiation burden. This study showed that Tc-99m-3PRGD(2) would be a safe and attractive SPECT agent in clinic applications.