TY - JOUR T1 - Radiation Dose of the P-Glycoprotein Tracer <sup>11</sup>C-Laniquidar JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 2101 LP - 2103 DO - 10.2967/jnumed.113.120857 VL - 54 IS - 12 AU - Andrey Postnov AU - Femke E. Froklage AU - Arthur van Lingen AU - Jaap C. Reijneveld AU - N. Harry Hendrikse AU - Albert D. Windhorst AU - Robert C. Schuit AU - Jonas Eriksson AU - Adriaan A. Lammertsma AU - Marc C. Huisman Y1 - 2013/12/01 UR - http://jnm.snmjournals.org/content/54/12/2101.abstract N2 - Resistance to current drug therapy is an important issue in the treatment of epilepsy. Inadequate access of central nervous system drugs to their targets in the brain may be caused by overexpression or overactivity of multidrug transporters, such as P-glycoprotein (P-gp), at the blood–brain barrier. Laniquidar, an inhibitor of P-gp, has been labeled with 11C for use in PET studies of P-gp expression in humans. Given potential interspecies differences in biodistribution, the purpose of this study was to ensure safe use of 11C-laniquidar by determining the dosimetry of 11C-laniquidar using whole-body PET studies. Methods: Six healthy volunteers were subjected to a series of 10 whole-body PET scans within approximately 70 min. Five blood samples were taken during the series. Results: High uptake of 11C-laniquidar was seen in liver, spleen, kidneys, and lung, whereas brain uptake was low. The effective dose for 11C-laniquidar was 4.76 ± 0.13 and 3.69 ± 0.01 μSv·MBq−1 for women and men, respectively. Conclusion: Biodistribution and measured effective dose indicate that 11C-laniquidar is a safe tracer for PET imaging, with a total dose of about 2 mSv for a brain PET/CT protocol. ER -