Abstract
The main focus of this study was to assess the in vivo distribution and radiation absorbed dose of 11C-nicotine derived from the whole body Positron emission tomography (PET) imaging in humans. Methods: After an initial Computed tomography (CT) attenuation scan, 11C-nicotine was administered via an intravenous injection, and dynamic whole body PET scans were acquired in a 3-D mode on 11 normal healthy (5 male, 6 female) subjects. The first scan was acquired in a dynamic acquisition mode for 90 s with the brain in the field of view, followed by a series of whole body PET scans acquired over a 90 min time period. Regions of interest were drawn over organs visible in the reconstructed PET images. Time activity curves were generated and the residence times were calculated. The radiation absorbed dose for the whole body was calculated by entering the residence time in OLINDA/EXM 1.0 software to model the equivalent organ dose and the effective dose for a 70 kg man. Results: The mean residence times for the 11C-nicotine in the liver, bone marrow, brain, and lungs were 0.048 ± 0.010, 0.031 ± 0.005, 0.021 ± 0.004, and 0.020 ± 0.005 h, respectively. The mean effective dose for 11C-nicotine was 5.44 ± 0.67 µSv/MBq. The organs receiving the highest radiation absorbed dose from the 11C-nicotine injection were the urinary bladder wall (14.68 ± 8.70 µSv/MBq), the kidneys (9.56 ± 2.46 µSv/MBq), liver (8.94 ± 1.67 µSv/MBq) and the spleen (9.49 ± 3.89 µSv/MBq). The renal system and hepatobiliary systems were the major clearance and excretion routes for radioactivity. Conclusions: The estimated radiation dose burden from 11C-nicotine administration is relatively modest. The low radiation dose for 11C-nicotine would allow for multiple PET examinations on the same research subject.
- Copyright © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.