Monte Carlo simulations of absorbed dose in a mouse phantom from 18-fluorine compounds.
The purpose of this study was to calculate internal absorbed dose distribution in mice from pre-clinical small animal PET imaging procedures with fluorine-18 labeled compounds (18FDG, 18FLT, and fluoride ion). The GATE Monte Carlo software and a realistic, voxel-based mouse phantom that included a subcutaneous tumor were used to perform simulations. Discretized time-activity curves obtained from dynamic in vivo studies with each of the compounds were used to set the activity concentration in the simulations. For 18FDG, a realistic range of uptake ratios was considered for the heart and tumor. For each simulated time frame, the biodistribution of the radionuclide in the phantom was considered constant, and a sufficient number of decays were simulated to achieve low statistical uncertainty. Absorbed dose, which was scaled to take into account radioactive decay, integration with time, and changes in biological distribution was reported in mGy per MBq of administered activity for several organs and uptake scenarios. The mean absorbed dose ranged from a few mGy/MBq to hundreds of mGy/MBq. Major organs receive an absorbed dose in a range for which biological effects have been reported. The effects on a given investigation are hard to predict; however, investigators should be aware of potential perturbations especially when the studied organ receives high absorbed dose and when longitudinal imaging protocols are considered.
Taschereau
Richard
R
The Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, 700 Westwood Boulevard, Los Angeles, California 90095, USA.
Chatziioannou
Arion F
AF
D000818:Animals; D001853:Bone Marrow / Q000473:pathology; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D005462:Fluorine Radioisotopes / Q000494:pharmacology*; D019788:Fluorodeoxyglucose F18 / Q000737:chemistry*; D051379:Mice; D015233:Models, Statistical; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D011874:Radiometry / Q000379:methods; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D012984:Software; D014018:Tissue Distribution
D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18