PT - JOURNAL ARTICLE AU - Liu, Zhiguo AU - Cheng, Kai AU - Fu, Zheng TI - A custom-made platform for radiopeptide optimization and dose on demand radiosynthesis DP - 2021 May 01 TA - Journal of Nuclear Medicine PG - 70--70 VI - 62 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/62/supplement_1/70.short 4100 - http://jnm.snmjournals.org/content/62/supplement_1/70.full SO - J Nucl Med2021 May 01; 62 AB - 70Objectives: The radiolabeled peptides have emerged as an important class of radiopharmaceuticals for tumor diagnosis and therapy. The concept of using peptide tracer to target receptor-expressing tissues in vivo has stimulated a large body of research in nuclear medicine. Although the commercially available synthesizer for radiopeptide labeling, such as 68Ga chelating, was used for routine production, the system was just dedicated to formulate the 68Ga tracer and was not suitable for other kind of chelated radiolabeling (e.g. for 64Cu, 177Lu, Al18F etc.). Unfortunately, up to now, there is no universal and interoperable module that allows the automation of chelate-based radiolabeling more generally with a single system. To address the problem, we aimed to design and assemble a custom-made platform that was suitable for conducting a series type of radiochelated reactions. Furthermore, the optimization for the procedure can also be implemented during the radiopeptide development. In order to validate the design concept of the platform and its potential in different type of radiolabeling with the various radioisotope resources, 68Ga-PSMA-11 and 18F-AlF-Alfatide II were investigated on the platform to validate the design concept and the feasibility for radio-chelated optimization and dose on demand radiosynthesis. Methods: As shown in Fig.1A, the whole system was consisted of three layers: conceptual layer (unit operations), digital layer (the custom-programing protocol), and physical layer (the hardware for the platform, including the syringe pump, valve, heating block, and MCU controller). The physical architecture of the platform contains four modular blocks. Each of them could fulfill the procedure of the unit operation, including isotope elution, reagent solution transferring, radiolabeling and purification and formulation, respectively. Each part of the block, except for the radiolabeling one, contains one syringe pump, one distribution valve, one switch valve and the pipeline for connection. The radiolabeling module include two self-governed heating blocks. Each of them was equipped with one heating jacket, one reactor and one corresponding 2-position 4-port switching valve. The fluid path of the platform was showed in Fig.1B. Finally, we demonstrated the automatic radiosynthesis of two representative tracers, 68Ga-PSMA-11, generator-based production and 18F-AlF-Alfatide II, cyclotron-based production. Results: The procedure of isotope elution, either the direct elution of the 68Ga from the generator or concentration of 18F from the cyclotron employing the QMA cartridge, could be accomplished no more than 3 min with the efficiency exceeding 95%. After the activity was eluted into the intermediate vial, the reagents solution, such as the buffer, precursor and other agents, could be transferred into the reactor by the syringe pump with accurate and precise fluidic control. The radiolabeling module contains two heating blocks. The appeal of this design is that it is expandable: The user can add more heating units to the ends of this module. This technique allows the researcher to operate multi-batch reactions in parallel for the tracer’ optimization, as well as to product the certain tracer under the optimal condition in the principle of dose on demand. On the basis of optimization, these tracers could be synthesized in the range of 1.11-3.70 GBq, yielding the isolated product in a decay-corrected radiochemical yield of 37±10% for 18F-AlF-Alfatide II (n=27) and 82±6% for 68Ga-PSMA-11 (n=18), respectively. Conclusions: The platform is modularized designed, whose stability and flexibility are greatly improved compared with the cassette-based systems. These features allow the use of a single system and hot cell for both synthesis development and routine production, enabling further increases in the duty cycle of the radiochemistry equipment and facilities. Research Support: This study was partially funded by NSFC 81601554.