1-[CARBON-11]-GLUCOSE RADIATION-DOSIMETRY AND DISTRIBUTION IN HUMAN IMAGING STUDIES

l-[Carbon-11]-D-glucose ([C-11]-glucose) is an important imaging agent for PET studies that have been used to study the normal brain, enceph alitis, epilepsy, manic-depressive disorder, schizophrenia and brain t umors. Methods: Dosimetry estimates were calculated in subjects underg oing imaging studies to help define the radiation risk of [(11C)]-gluc ose PET imaging. Time-dependent radioactivity concentrations in normal tissues in 33 subjects after intravenous injection of [C-11]-glucose were obtained by PET imaging. Radiation absorbed doses were calculated according to the procedures of the Medical Internal Radiation Dose (M IRD) committee along with the variation in dose based on the calculate d standard deviation of activity distribution seen in the individual p atients. Results: Total body exposure was a median of 3.0 mu Gy/MBq in men and 3.8 mu Gy/MBq in women. The effective dose equivalent was 3.8 mu Gy/MBq in men and 4.8 mu Gy/MBq in women. The critical organs were those that typically take up the most glucose (brain, heart wall and liver). Conclusion: The organ doses reported here are small and compar able to those associated with other commonly performed nuclear medicin e tests and indicate that potential radiation risks associated with th is radiotracer are within generally accepted limits.