Authors: W-Y Tseng
Affilation: University of California, Los Angeles, United States
Pages: 472 - 475
Keywords: PDMS microfluidic chip, positron emission tomography, Cerenkov images, radiosynthesis
Positron Emission Tomography (PET) is a powerful imaging tool with high sensitivity and molecular specificity. Microfluidic systems have shown great promise for the preparation of PET tracers labeled with fluorine-18 (F-18), especially those based on polydimethylsiloxane (PDMS), due to their ability to manipulate nanoliter to microliter volumes with high precision. However, previous studies have alluded to incompatibilities of PDMS with 18F-radiosyntheses, with frequent observations of device failures and F-18 loss. Poor understanding of these issues has limited further progress in this technology. Recently we developed a novel quantitative radioactivity imaging system, based on the detection of Cerenkov radiation that can provide insights into the detailed operation of microfluidic devices during radiotracer production. Also, we have redesigned and developed PDMS chips for [18F]fluoride drying. Our in-depth study characterized two distinct patterns of evaporation and correlated them with reliability of the chip and loss of fluoride-18 during evaporation. Based on these results, a new generation chip is designed to control the evaporation pattern and minimize fluoride-18 loss. Also, we are in the process of designing new PDMS radiosynthesizer chips to continue our study of the remaining synthesis steps.