because 18f has a relatively short physical half-life ( t1/2 = 110 min ) , and the distribution and kinetics of the radiolabeled 5-fluorouracil need to be studied over periods of time that range over several half-lives of the radionuclide , significant quantities of the labeled drug must be administered in order to obtain good counting statistics .
C0018517
half-life
C0022702
kinetics