1-[Carbon-11 ]-glucose radiation dosimetry and distribution in human imaging studies

1-[Carbon-11]-D-glucose ([¹¹C]-glucose) is an important imaging agent for PET studies that have been used to study the normal brain, encephalitis, epilepsy, manic-depressive disorder, schizophrenia and brain tumors. Methods: Dosimetry estimates were calculated in subjects undergoing imaging studies to help define the radiation risk of [¹¹C]-glucose PET imaging. Time-dependent radioactivity concentrations in normal tissues in 33 subjects after intravenous injection of [¹¹C]-glucose were obtained by PET imaging. Radiation absorbed doses were calculated according to the procedures of the Medical Internal Radiation Dose (MIRD) committee along with the variation in dose based on the calculated standard deviation of activity distribution seen in the individual patients. Results: Total body exposure was a median of 3.0 μGy/MBq in men and 3.8 μGy/MBq in women. The effective dose equivalent was 3.8 μGy/MBq in men and 4.8 μGy/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 comparable to those associated with other commonly performed nuclear medicine tests and indicate that potential radiation risks associated with this radiotracer are within generally accepted limits.