Pharmacokinetics and radiation dosimetry of 18F-fluorocholine.
18F-Fluorocholine (fluoromethyl-dimethyl-2-hydroxyethylammonium [FCH]) has been developed as an oncologic probe for PET. This study evaluates the kinetics and radiation dosimetry of 18F-FCH using murine and human biodistribution data.


METHODS
The biodistribution of 18F-FCH was obtained at time points up to 10 h after administration in control and tumor-bearing anesthetized nude mice. Human biodistribution data within the first hour after injection were obtained from attenuation-corrected whole-body PET scans of male (n = 7) and female (n = 5) cancer patients. Radiation dosimetry estimates were calculated using the murine and human biodistribution data assuming no redistribution of tracer after 1 h.


RESULTS
Rapid pharmacokinetics were observed for 18F-FCH in mice and humans. The biodistribution is nearly static after 10 min. The dose-critical organ is the kidney, which receives 0.17 +/- 0.05 and 0.16 +/- 0.07 mSv/MBq (0.64 +/- 0.18 and 0.55 +/- 0.32 rad/mCi) for females and males, respectively. The effective dose equivalent (whole body) from administration of 4.07 MBq/kg (0.110 mCi/kg) is approximately 0.01 Sv for females and males.


CONCLUSIONS
18F-FCH is rapidly cleared from the circulation and its biodistribution changes very slowly at >10 min after administration. The kidney is the dose-critical organ and limits administration levels of 18F-FCH to 4.07 MBq/kg (0.110 mCi/kg) in human research studies.
DeGrado
Timothy R
TR
Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA. trd@petsparc.mc.duke.edu
Reiman
Robert E
RE
Price
David T
DT
Wang
Shuyan
S
Coleman
R Edward
RE
D000818:Animals; D001943:Breast Neoplasms / Q000000981:diagnostic imaging; D005260:Female; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D006801:Humans; D007668:Kidney / Q000528:radiation effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging; D000644:Quaternary Ammonium Compounds / Q000493:pharmacokinetics*; D011829:Radiation Dosage; D011874:Radiometry; D013997:Time Factors; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed; D014183:Transplantation, Heterologous
D005462:Fluorine Radioisotopes; D000644:Quaternary Ammonium Compounds; C419185:fluoromethyl dimethyl-2-hydroxyethylammonium