Production, processing and small animal PET imaging of titanium-45.
BACKGROUND
Titanium-45 was prepared as a tool for elucidation of the mechanism of action of titanium anticancer drugs in vivo using microPET imaging.


METHODS
Titanium-45 was produced by the 45Sc(p,n)45Ti nuclear reaction using 14.5 MeV protons. Sufficient yields of 45Ti were produced and separated from the target material with 99.8% radionuclidic purity using a simple, efficient separation procedure.


RESULTS
A typical bombardment of 5 microA for 1 h produced an average of 2105+/-150 MBq (56.9+/-4.0 mCi) at the end of bombardment (EOB), well within acceptable range of the calculated theoretical yields of 2165 MBq and 433 MBq microA-1 h-1 (58.5 mCi and 11.7 mCi microA-1 h-1). This amount of activity is sufficient for the radiosynthesis of target compounds as well as imaging studies. MicroPET images of a miniature Derenzo phantom show excellent resolution where rods of 1.25 mm were separated by four times their diameter.


CONCLUSIONS
Titanium-45 can be easily produced on a biomedical cyclotron with excellent yields as compared to calculated theoretical values with imaging studies demonstrating that the decay properties of titanium-45 are well suited for microPET.
Vāvere
Amy L
AL
Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Laforest
Richard
R
Welch
Michael J
MJ
D000818:Animals; D007089:Image Enhancement / Q000379:methods*; D007553:Isotope Labeling / Q000379:methods; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000295:instrumentation / Q000379:methods* / Q000662:veterinary*; D011868:Radioisotopes / Q000737:chemistry*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis; D014025:Titanium / Q000737:chemistry*
D011868:Radioisotopes; D019275:Radiopharmaceuticals; D014025:Titanium