on the optimization of the protocol for automated radiosyntheses of [68ga]ga-pentixafor, [68ga]ga-fapi-4 and [68ga]ga-dotatate in a modular-lab standard

Objective: the present work describes the automated radiochemical syntheses of different pet tracers like [68ga]ga-pentixafor, [68ga]ga-fapi-4 and [68ga]ga-dotatate using optimized single protocol in the non-cassette based eckert & ziegler (ez) modular lab (fixed tubing system) without any modification in the inbuilt human machine interface (hmi) software. recently, pet agents viz. [68ga]ga-pentixafor and [68ga]ga-fapi-4 are gaining prominence for the diagnosis of overexpressed chemokine receptor-4 (cxcr4) and fibroblast activation protein (fap) receptor, respectively, in the microenvironment of numerous cancer types. the promising results observed with the clinical usage of [68ga]ga-dotatate produced using the automated protocol, provided impetus for the clinical translation of [68ga]ga-pentixafor and [68ga]ga-fapi-4 using the in-house developed automated radiolabeling protocol.methods: herein we report a single radiolabeling protocol for the automated preparation of [68ga]ga-pentixafor and [68ga]ga-fapi-4 in the non-cassette based ez modular-lab standard radiochemistry module, without any changes in schematic, graphical user interface (gui) software and time list, from that used for routine production of [68ga]ga-dotatate in our centre, since 2015. physico-chemical quality control and in-vitro stability analyses were carried out using radio-tlc and radio-hplc.results: the automated protocol yielded reliable and consistent non-decay corrected (ndc) radiochemical yield (rcy) of (84.4±0.9)% and (85.5±1.4)% respectively, for [68ga]ga-pentixafor and [68ga]ga-fapi-4, with rcp> 98%, which are comparable to the rcy of (84.4±1.2)% and rcp (99.1±0.3)% for [68ga]ga-dotatate. the biological quality control studies confirmed the formulations to be of ready-to-use pharmaceutical grade.conclusion: the consistent and reliable rcy and rcp of multiple 68ga-labeled pet tracers by single optimized automated radiochemistry protocol exhibits the versatility of the ez modular lab.