@article {Challapalli256, author = {Amarnath Challapalli and Rohini Sharma and William A. Hallett and Kasia Kozlowski and Laurence Carroll and Diana Brickute and Frazer Twyman and Adil Al-Nahhas and Eric O. Aboagye}, title = {Biodistribution and Radiation Dosimetry of Deuterium-Substituted 18F-Fluoromethyl-[1, 2-2H4]Choline in Healthy Volunteers}, volume = {55}, number = {2}, pages = {256--263}, year = {2014}, doi = {10.2967/jnumed.113.129577}, publisher = {Society of Nuclear Medicine}, abstract = {11C-choline and 18F-fluoromethylcholine (18F-FCH) have been used in patients to study tumor metabolic activity in vivo; however, both radiotracers are readily oxidized to respective betaine analogs, with metabolites detectable in plasma soon after injection of the radiotracer. A more metabolically stable FCH analog, 18F-fluoromethyl-[1,2-2H4]choline (18F-D4-FCH), based on the deuterium isotope effect, has been developed. We report the safety, biodistribution, and internal radiation dosimetry profiles of 18F-D4-FCH in 8 healthy human volunteers. Methods: 18F-D4-FCH was intravenously administered as a bolus injection (mean {\textpm} SD, 161 {\textpm} 2.17 MBq; range, 156{\textendash}163 MBq) to 8 healthy volunteers (4 men, 4 women). Whole-body (vertex to mid thigh) PET/CT scans were acquired at 6 time points, up to 4 h after tracer injection. Serial whole-blood, plasma, and urine samples were collected for radioactivity measurement and plasma radiotracer metabolites. Tissue 18F radioactivities were determined from quantitative analysis of the images, and time{\textendash}activity curves were generated. The total numbers of disintegrations in each organ normalized to injected activity (residence times) were calculated as the area under the curve of the time{\textendash}activity curve normalized to injected activities and standard organ volumes. Dosimetry calculations were performed using OLINDA/EXM 1.1. Results: The injection of 18F-D4-FCH was well tolerated in all subjects, with no radiotracer-related serious adverse event reported. The mean effective dose averaged over both men and women ({\textpm}SD) was estimated to be 0.025 {\textpm} 0.004 (men, 0.022 {\textpm} 0.002; women, 0.027 {\textpm} 0.002) mSv/MBq. The 5 organs receiving the highest absorbed dose (mGy/MBq) were the kidneys (0.106 {\textpm} 0.03), liver (0.094 {\textpm} 0.03), pancreas (0.066 {\textpm} 0.01), urinary bladder wall (0.047 {\textpm} 0.02), and adrenals (0.046 {\textpm} 0.01). Elimination was through the renal and hepatic systems. Conclusion: 18F-D4-FCH is a safe PET radiotracer with a dosimetry profile comparable to other common 18F PET tracers. These data support the further development of 18F-D4-FCH for clinical imaging of choline metabolism.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/55/2/256}, eprint = {https://jnm.snmjournals.org/content/55/2/256.full.pdf}, journal = {Journal of Nuclear Medicine} }