PET Imaging with [ 68 Ga]NOTA-RGD for Prostate Cancer: A Comparative Study with [ 18 F]Fluorodeoxyglucose and [ 18 F]Fluoroethylcholine

The α v β 3 integrin is highly expressed in prostate cancer (PCa), in which it is a key player in tumour invasion, angiogenesis and metastasis formation. Therefore, α v β 3 integrin is considered a very promising target for molecular imaging of PCa. This study tested the potential of the novel α v β 3 integrin affine agent [ 68 Ga]NOTA-RGD in comparison with the established [ 18 F]fluoroethylcholine (FEC) and [ 18 F]fluorodeoxyglucose (FDG) for assessing PCa using positron emission tomography (PET). [ 68 Ga]NOTA-RGD showed a lower uptake in PC-3 and DU-145 cells compared with FEC and FDG. µPET imaging studies showed a good delineation of the PCa xenografts in mice. The means tumor-to-muscleand tumor-to-bone-ratio amounted 5.1 ± 1.4 and 5.2 ± 1.2 for [ 68 Ga]NOTA-RGD compared with 2.6 ± 0.9 and 2.9 ± 1.6 for FDG, and 2.4 ± 0.7 and 0.8 ± 0.2 for FEC, respectively. The uptake of [ 68 Ga]NOTA-RGD into tumor was fully inhibited by c(RGDfV), known to bind specifically to α v β 3 integrin, confirming the specificity of the tumor uptake in vivo. These results suggest that [ 68 Ga]NOTA-RGD is a promising candidate for PET imaging of α v β 3 integrin expression in PCa and warrant further in vivo validations to ascertain its potential as an imaging agent for clinical use. The simple and fast preparation of [ 68 Ga]NOTA-RGD may greatly facilitate its translation to a clinical setting.