Advantage of accelerator mass spectrometry (AMS) for drug research

1514 Objectives AMS system is an ultrasensitive analytical method used for carbon dating by measuring radiocarbon (14C) concentrations. AMS method, along with PET, is going to be applied for drug development. We evaluated the performance of AMS system and the correlation with PET. Methods AMS measurement was performed by using tandem electrostatic accelerator (NEC 1.5SDH-1 0.6MV Pelletron AMS system). It was well-known that 14C was ecologically distributed through atmosphere, biosphere and living things. We first underwent measurement of background 14C level in human and animal using AMS system. We then clarify the relationship of measurement of tissue distribution between AMS and PET by administering 14C-2-fluoro-2-deoxyglucose (14C-FDG)and 18F-2-fluoro-2-deoxyglucose (18F-FDG)simultaneously to mice. Results The background 14C concentration differed according to the particular type of tissue sample measured. The background 14C-concentration in mouse liver was higher than other organs, and was approximately two-times that of blood. The correlation coefficient (r) of the measurements using PET (18F-FDG) and AMS (14C-FDG) were quite high at 0.99 in blood, 0.97 in brain and 0.74 in liver. The blood clearance profile of 18F-FDG was nearly identical with that of 14C-FDG. Conclusions AMS system provided ultrasensitive analyses in measuring background 14C concentrations in human and animal. The background 14C concentration differed according to the particular type of tissue sample measured. The background 14C concentrations should be taken into consideration for measurement of administrated 14C labeled drug concentration. AMS analysis has excellent correlation with the PET biodistribution measurements.