Radiolabeling and Imaging of PRGD2 Peptide

A lyophilized kit for labeling the PRGD2 peptide purchased from the Jiangsu Institute of Nuclear Medicine was employed according to a previously published study (15 (link)). The radiochemical purity of ¹⁸F−RGD exceeded 95%, and its specific radioactivity exceeded 37 GBq (1,000 mCi)/µmol. All micro-PET images were obtained with an Inveon PET scanner (Siemens Preclinical Solutions, LLC, Knoxville, TN, USA) using ¹⁸F−RGD. With the assistance of the positioning laser from the Inveon system, each tumor-bearing mouse was placed with its tumor located in the center of the field of view to achieve the highest imaging sensitivity. ¹⁸F-RGD PET scans were performed 60 min after tail-vein injection of ¹⁸F−RGD (2.4−3.5 MBq) under isoflurane anesthesia with 1.5% isoflurane in 100% oxygen at a flow rate of 1.5 L/min. The PET scans were acquired on a combined PET/CT scanner for 5 min per field of view. The PET images were reconstructed and analyzed using the OSEM−3D IAM software program (IS_v1.4.3 SP1; Siemens Preclinical Solutions, LLC).