development of an 18f radiolabeling method using solid phase chemistry
abstract
new radiotracers are constantly being developed to expand the clinical applications of
positron emission tomography (pet). one of the challenges in the development of pet tracers
is the incorporation of a positron emitting isotope. short half-lives combined with added
safety measures when working with radioactive materials require a fast and simple synthesis.
this project describes a solid phase fluorine-18 (t1/2 = 110 min) radiolabeling procedure that
allows removal of impurities through filtration. the synthesis takes an indirect approach by
first labeling a small molecule with f-18 and then coupling this molecule to an amine
containing compound using solid phase dichlorotriazine (dct).
this procedure has been used to label various compounds containing primary and secondary
amine groups without the need for an additional purification step. the total synthesis time
required is approximately 80 min from the from delivery of the [
18f]fluoride, with a decay
corrected radiochemical yield of 3% for the example tested (yield will likely vary depending
on the substrate). this demonstrates the potential of solid phase reagents like dct to be used
in radiolabeling, but further development is required to improve yields for this reaction.