Preclinical PET imaging of HIP/PAP using 1'-18F-fluoroethyl-β-D-lactose

The Role of Positron Emission Tomography/Computed Tomography (PET/CT) for Staging and Disease Response Assessment in Localized and Locally Advanced Pancreatic Cancer

Pancreatic Cancer (PC) has a poor prognosis, with a 5-year survival rate of only 9%. Even after radical surgical procedures, PC patients have poor survival rates, with a high chance of relapse (70-80%). Imaging is involved in all aspects of the clinical management of PC, including detection and characterization of primary tumors and their resectability, assessment of vascular, perineural and lymphatic invasion and detection of distant metastases. The role of Positron Emission Tomography/Computed Tomography (PET/CT) in detecting PC is still controversial, with the international guidelines not recommending its routine use. However, in resectable PC, PET/CT may play a role in assessing PC stage and grade and potential resectability after neoadjuvant treatment. Quantitative image analysis (radiomics) and new PET/CT radiotracers account for future developments in metabolic imaging and may further improve the relevance of this technique in several aspects of PC. In the present review, the current state of the art and future directions of PET/CT in resectable PC are presented.

Preclinical evaluation of a dual sstr2 and integrin αvβ3-targeted heterodimer [68Ga]-NOTA-3PEG4-TATE-RGD

PURPOSE

Multiple receptors are co-expressed in many types of cancers. Octreotate (TATE) and Arg-Gly-Asp (RGD) peptides target somatostatin receptor 2 (sstr2) and integrin α_vβ₃, respectively. We developed and synthesized a heterodimer NOTA-3PEG₄-TATE-RGD (3PTATE-RGD) and aimed to investigate its characteristics for dual-targeting sstr2 and integrin α_vβ₃.

METHODS

TATE and RGD peptides and 1,4,7-triazacylononane-N',N'',N'''-triacetic acid (NOTA) were linked through a glutamate and polyethylene glycol (PEG) linker, then 3PTATE-RGD was labeled with ⁶⁸Ga ion. Receptor-binding characteristics and tumor-targeting efficacy were tested in vitro and in vivo using H69 and A549 lung cancer cell lines and tumor-bearing mice models.

RESULTS

[⁶⁸Ga]-3PTATE-RGD had comparable sstr2 and integrin α_vβ₃-binding affinity with monomeric TATE and RGD in cell uptake and PET imaging study, respectively. In the competition study, H69 and A549 tumor uptake of [⁶⁸Ga]-3PTATE-RGD was completed inhibited in the presence of an excess amount of unlabeled TATE or RGD, respectively. The blocked level didn't grow when both of TATE and RGD mixture was co-injected with [⁶⁸Ga]-3PTATE-RGD. The pharmacokinetics of [⁶⁸Ga]-3PTATE-RGD is comparable with [⁶⁸Ga]-TATE and [⁶⁸Ga]-RGD, resulting in a larger application.

CONCLUSION

[⁶⁸Ga]-3PTATE-RGD showed improved and wider tumor-targeting efficacy compared with monomeric TATE and RGD peptides, which warrants its further investigation in detection both of sstr2 and integrin α_vβ₃-related carcinomas.