Development of single vial kits for preparation of 68Ga-labelled peptides for PET imaging of neuroendocrine tumours

摘要

Purpose: The present work was aimed at the formulation and evaluation of freeze-dried kits of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-peptides for the preparation of 68Ga-labelled peptides for PET imaging of neuroendocrine tumours. The 68GaCl3 was obtained from the locally produced nanoceria-PAN, composite-sorbent-based 68Ge/68Ga generator. Procedures: Single vial kits of somatostatin analogues DOTA-[Tyr3]-octreotide (DOTA-TOC), DOTA-[NaI3]-octreotide (DOTA-NOC) and DOTA-Tyr3-Thre 8-octreotide (DOTA-TATE) were formulated. Optimization of radiolabelling with 68Ga from the in-house generator, characterization, long term evaluation of stability of kits and bioevaluation studies in animals was carried out. Results: DOTA-TOC, DOTA-NOC and DOTA-TATE kits could be successfully formulated. Consistently high radiochemical yields (95 %) were obtained on radiolabelling with 68Ga. The radiolabelled peptides exhibited excellent in vitro stability. Biodistribution studies in normal non-tumour bearing Swiss mice revealed fast clearance of activity via renal route as reported for the respective peptides. Conclusion: Availability of ready to use DOTA-peptide kits in conjunction with 68Ge/68Ga generators would pave way for the establishment of 68Ga radiopharmacy, a long-felt need of the nuclear medicine community.