18F-Alfatide II PET/CT in healthy human volunteers and patients with brain metastases

Purpose We report the biodistribution and radiation dosimetry of an integrin alpha(v)beta(3) specific PET tracer F-18-AlF-NOTA-E[PEG(4)-c(RGDfk)](2)) (denoted as F-18-Alfatide II). We also assessed the value of F-18-Alfatide II in patients with brain metastases. Methods A series of torso (from the skull to the thigh) static images were acquired in five healthy volunteers (3 M, 2 F) at 5, 10, 15, 30, 45, and 60 min after injection of F-18-Alfatide II (257 +/- 48 MBq). Regions of interest (ROIs) were drawn manually, and the time-activity curves (TACs) were obtained for major organs. Nine patients with brain metastases were examined by static PET imaging with F-18-FDG (5.55 MBq/kg) and F-18-Alfatide II. Results Injection of F-18-Alfatide II was well tolerated in all healthy volunteers, with no serious tracer-related adverse events found. F-18-Alfatide II showed rapid clearance from the blood pool and kidneys. The total effective dose equivalent (EDE) and effective dose (ED) were 0.0277 +/- 0.003 mSv/MBq and 0.0198 +/- 0.002 mSv/MBq, respectively. The organs with the highest absorbed dose were the kidneys and the spleen. Nine patients with 20 brain metastatic lesions identified by MRI and/or CT were enrolled in this study. All 20 brain lesions were visualized by F-18-Alfatide II PET, while only ten lesions were visualized by F-18-FDG, and 13 by CT. Conclusion F-Alfatide II is a safe PET tracer with a favorable dosimetry profile. The observed ED suggests that F-18-Alfatide II is feasible for human studies. F-18-Alfatide II has potential value in finding brain metastases of different cancers as a biomarker of angiogenesis.