AI18F-3p-C-NETA-TATE: Combining a versatile and highly effective chelator with an established somatostatin analogue

Autor: Ahenkorah, S., Murce, E., Seimbille, Y., Cardinaels, T., Deroose, C. M., Bormans, G., Ooms, M., Cleeren, F.
Přispěvatelé: Radiology & Nuclear Medicine
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: European Journal of Nuclear Medicine and Molecular Imaging, 48(SUPPL 1), S195-S196. Springer-Verlag
ISSN: 1619-7070
Popis: Aim/Introduction: Somatostatin-based radiopharmaceuticals (e.g. [68Ga]Ga-DOTATATE and [177Lu]Lu-DOTATATE) have been used to diagnose, monitor, and treat neuroendocrine tumour patients with great success. [18F]AlF-NOTA-octreotide, a promising 18F-labeled somatostatin analogue and potential alternative for 68GaDOTA-peptides, is under clinical evaluation. Ideally, the same precursor (combination of chelator-linker-vector) can be used for production of both diagnostic and therapeutic radiopharmaceuticals with very similar (e.g. Al18F/213Bi/177Lu) or identical (e.g. complementary Tb-radionuclides) pharmacokinetic properties, allowing accurate, personalised dosimetry estimation and radionuclide therapy of NET patients. In this study we evaluate the versatile and highly effective chelator 3p-C-NETA3 and present first results of radiosynthesis and stability of Al[18F]F-3p-C-NETA-TATE. Materials and Methods: 3p-C-NETA was radiolabelled with diagnostic (68Ga, Al18F) or therapeutic (177Lu,161Tb,213Bi) radionuclides at different temperatures. The in vitro stability of the corresponding radiocomplexes was determined in PBS and human serum at 37 °C. 3p-C-NETA-TATE was synthesised using standard solid-phase peptide synthesis and purifed using HPLC. Al[18F]F-3p-C-NETA-TATE was synthesised in an automated AllInOne module and analysed using radio-HPLC. Finally, the in vitro stability of Al[18F]F-3p-C-NETA-TATE was evaluated in formulation buffer, PBS and human serum at 37 °C. Results: 3p-C-NETA was efficiently labelled with 177Luand 213Bi (RCY>95%) at room temperature and with 161Tb(>95%) and 68Ga (>90%) at 55 °C. Al18F-labeling required a higher temperature of 95 °C to achieve good yields (>85%).The 177Lu- and 161Tb-3p-C-NETA-complex showed excellent invitro stability in both PBS and human serum over a period of eight days (97% intact). We also observed high in vitro stability up to 2 h for Al[18F]F-3p-C-NETA-TATE (>93% intact in PBS and human serum). In contrast, [68Ga]Ga-3p-C-NETA was stable in PBS (>90% intact), but not in human serum (only 60% intact after 2h). Al[18F]F-3p-C-NETA-TATE was obtained in good RCY (56%) and radiochemical purity (98%). Al[18F]F-3pC-NETA-TATE displayed excellent in vitro stability with >95%intact tracer after 4 hours in all tested conditions. Conclusion: 3p-C-NETA is an excellent chelator that can be used for both targeted radionuclide therapy (177Lu, 213Bi and 161Tb) and diagnostic applications (Al18F) and has the potential to replace DOTA analogues in current clinical use. Al[18F]F-3p-CNETA-TATE will be further evaluated using µPET/MRI imaging in healthy rats and SSTR2 positive tumour mice, in a head-to-head comparison with Al18F-NOTA-octreotide. °
Databáze: OpenAIRE