1. Academic Validation
  2. Whole-body radiation dosimetry of 11C-carbonyl-URB694: a PET tracer for fatty acid amide hydrolase

Whole-body radiation dosimetry of 11C-carbonyl-URB694: a PET tracer for fatty acid amide hydrolase

  • J Nucl Med. 2014 Dec;55(12):1993-7. doi: 10.2967/jnumed.114.146464.
Isabelle Boileau 1 Peter M Bloomfield 2 Pablo Rusjan 3 Romina Mizrahi 4 Asfandyar Mufti 5 Irina Vitcu 2 Stephen J Kish 6 Sylvain Houle 3 Alan A Wilson 7 Junchao Tong 8
Affiliations

Affiliations

  • 1 Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Human Brain Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science, Toronto, Ontario, Canada isabelle.boileau@CAMH.ca.
  • 2 Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
  • 3 Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
  • 4 Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada Institute of Medical Science, Toronto, Ontario, Canada.
  • 5 Institute of Medical Science, Toronto, Ontario, Canada.
  • 6 Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Human Brain Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada; and Institute of Medical Science, Toronto, Ontario, Canada.
  • 7 Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
  • 8 Addiction Imaging Research Group, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Human Brain Laboratory, Centre for Addiction and Mental Health, Toronto, Ontario, Canada Campbell Family Mental Health Research Institute Centre for Addiction and Mental Health, Toronto, Ontario, Canada Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
Abstract

(11)C-carbonyl-URB694 ((11)C-CURB) is a novel (11)C-labeled suicide irreversible radiotracer for PET developed as a surrogate measure of activity of the endocannabinoid metabolizing Enzyme fatty acid amide hydrolase. The aim of the study was to investigate the whole-body biodistribution and estimate the radiation dosimetry from (11)C-CURB scans in humans.

Methods: Six healthy volunteers (3 men and 3 women) completed a single whole-body scan (∼120 min, 9 time frames) on a PET/CT scanner after administration of (11)C-CURB (∼350 MBq and ∼2 μg). Time-radioactivity curves were extracted in 11 manually delineated organs and corrected for injected activity, specific organ density, and volume to obtain normalized cumulated activities. OLINDA/EXM 1.1 was used to estimate standard internal dose exposure in each organ. The mean effective dose was calculated using the male and female models for the full sample and female-only sample, respectively.

Results: (11)C-CURB was well tolerated in all subjects, with no radiotracer-related adverse event reported. The mean effective dose (±SD) was estimated to be 4.6 ± 0.3 μSv/MBq for all subjects and 5.2 ± 0.3 μSv/MBq for the female sample. Organs with the highest normalized cumulated activities (in h) were the liver (0.117), gallbladder wall (0.046), and small intestine (0.033), and organs with the highest dose exposure (in μGy/MBq) were the gallbladder wall (111 ± 60) > liver (21 ± 7), kidney (14 ± 3), and small intestine (12 ± 2).

Conclusion: Organ radiation exposure for the irreversible fatty acid amide hydrolase Enzyme probe (11)C-CURB is within the same range as other radiotracers labeled with (11)C, thus allowing for safe, serial PET scans in the same individuals.

Keywords

11C-CURB; dosimetry; endocannabinoid system; fatty acid amide hydrolase; positron emission tomography.

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