Molecular Imaging and Biology

, Volume 14, Issue 4, pp 517–521

Biodistribution and Radiation Dosimetry of the Serotonin 5-HT6 Ligand [11C]GSK215083 Determined from Human Whole-Body PET

  • Robert A. Comley
  • Cristian Salinas
  • Romina Mizrahi
  • Irina Vitcu
  • Alvina Ng
  • William Hallett
  • Nicholas Keat
  • Alan A. Wilson
  • Eugenii A. Rabiner
  • Marc Laruelle
  • Sylvain Houle
Research Article

DOI: 10.1007/s11307-011-0523-1

Cite this article as:
Comley, R.A., Salinas, C., Mizrahi, R. et al. Mol Imaging Biol (2012) 14: 517. doi:10.1007/s11307-011-0523-1

Abstract

Purpose

We measured the whole-body distribution of IV-injected [11C]GSK215083, a new 5-HT6 antagonist PET tracer, as a function of time in adult subjects, in order to determine the radiation exposure.

Procedures

After injection with a single bolus of [11C]GSK215083 (range 330–367 MBq; mean 346 MBq), PET emission data were acquired for approximately 120 min in six subjects (three males and three females). Five organs were identified as exhibiting uptake above background. For these, regions of interest were delineated on emission images, and time–activity curves (TAC) generated. Residence times were calculated as the area under the curve of the TAC, normalized to injected activities and standard values of organ volumes. Dosimetry calculations were then performed using the computer program OLINDA/EXM 1.0.

Results

The mean effective dose averaged over both males and females (±standard deviation) was estimated to be 7.7 ± 1.0 μSv/MBq (male 7.0 ± 0.4; female 8.5 ± 0.6). For the effective dose equivalent, the corresponding values are 7.8 ± 1.2 μSv/MBq (male 6.8 ± 0.5; female 8.9 ± 0.1). The organ receiving the highest dose was the lung, with an average equivalent dose of 25.6 ± 6.9 μSv/MBq (male 20.8 ± 5.6; female 30.4 ± 4.4).

Conclusion

The estimated radiation dose for [11C]GSK215083 is consistent with those for other neuroreceptor ligands labeled with carbon-11. The somewhat higher dose estimate for females compared to males may reflect the difference in observed residence times and representative differences in the male and female phantoms used for dosimetry calculations. Based on conventionally accepted dose limits, [11C]GSK215083 may be used for multiple PET scans in the same subject.

Key words

Biodistribution Dosimetry Positron emission tomography [11C]GSK215083 5-HT6 antagonist 

Copyright information

© World Molecular Imaging Society 2011

Authors and Affiliations

  • Robert A. Comley
    • 1
  • Cristian Salinas
    • 1
  • Romina Mizrahi
    • 2
  • Irina Vitcu
    • 2
  • Alvina Ng
    • 2
  • William Hallett
    • 1
  • Nicholas Keat
    • 1
  • Alan A. Wilson
    • 2
  • Eugenii A. Rabiner
    • 1
  • Marc Laruelle
    • 1
  • Sylvain Houle
    • 2
  1. 1.GlaxoSmithKline Clinical Imaging CentreLondonUK
  2. 2.Centre for Addiction and Mental HealthTorontoCanada