18F-Alfatide II automated preparation based on 18F-minireactor and microPET/CT imaging in tumor

Objective To develop the automated preparation of 18F-Alfatide Ⅱ using newly-designed 18F-minireactor and perform 18F-Alfatide Ⅱ microPET/CT imaging in tumor. Methods The automated preparation of 18F-Alfatide Ⅱ was developed by using 18F-microreactor and water phase Al18F-chelating method, and the radiochemical yield and quality analysis were measured. The nude mice bearing breast tumor ZR-75-1 and nasopharyngeal tumor CNE1 were established (n=3 respectively). MicroPET/CT imaging was performed at 0.5, 1.0 and 2.0 h after the injection of 18F-Alfatide Ⅱ. The region of interest (ROI) was depicted and the tumor/muscle (T/M) ratio was calculated. Results 18F-Alfatide Ⅱ was automatically prepared with the total synthesis time of 40 min, the radiochemical yield of (28±6)% (no decay corrected, n=11), and the radiochemical purity >97%. All quality analysis indexes accorded with the radiopharmaceutical requirements. 18F-Alfatide Ⅱ microPET/CT images of ZR-75-1 and CNE1 tumors were clear due to the high radioactivity uptake of tumor lesions (T/M ratio was greater than 4.0 at 1.0 h after injection). Conclusion Based on the 18F-minireactor, the 18F-Alfatide Ⅱ can be prepared successfully with short synthesis time and high radiochemical yield, which can help the application studies in 18F-Alfatide Ⅱ microPET/CT imaging. Key words: Peptides, cyclic; Arg-Gly-Asp; Fluorine radioisotopes; Chemistry techniques, synthetic; Breast neoplasms; Nasopharyngeal neoplasms; Neoplasm transplantation; Mice, nude