[Tumor targeting efficacy of a novel PET radiotracer (1)8F-AlF-NOTA-PRGD2 in mice].

OBJECTIVE: To investigate the tumor targeting efficacy of (18)F-AlF-NOTA-PRGD2, a novel radiotracer of Arginine-glycine-aspartic acid (RGD) peptides.

METHODS: (18)F-AlF-NOTA-PRGD2 was synthesized in one-step by conjugating NOTA-PRGD2 with (18)F-AlF at 100 degrees celsius;. The tumor targeting efficacy and in vivo biodistribution profile of (18)F-AlF-NOTA-PRGD2, following intravenous injection via the tail vein, were evaluated in a nude mouse model bearing subcutaneous U87MG glioblastoma xenograft by radioactivity biodistribution assessment, PET/CT and microPET/CT.

RESULTS: NOTA-PRGD2 was (18)F-fluorinated successfully in one-step with a yield of 17%-25% within 15-20 min. Radioactivity biodistribution study confirmed the tumor-targeting ability of (18)F-AlF-NOTA-PRGD2 in the tumor-bearing mice. At 1 and 2 h following injection, (18)F-AlF-NOTA-PRGD2 uptake in the tumor reached 4.14∓1.44 and 2.80∓1.18 % ID/g (t=1.910, P=0.070) with tumor/brain ratios of 2.95∓0.61 and 5.21∓2.62, respectively (t=-1.686, P=0.167). Both PET/CT and microPET/CT were capable of showing the radioactivity biodistribution of (18)F-AlF-NOTA-PRGD2 in the mouse model and clearly displayed the tumor, but microPET/CT showed a much better image quality.

CONCLUSION: (18)F-AlF-NOTA-PRGD2 prepared by one-step radiosynthesis can selectively target to the tumor, demonstrating its potential as a good radiotracer for tumor imaging.