Human biodistribution and radiation dosimetry of 11C-(R)-PK11195, the prototypic PET ligand to image inflammation

Abstract

The positron emission tomography (PET) radiotracer 11C-(R)-PK11195 allows the in vivo imaging in humans of the translocator protein 18 kDa (TSPO), previously called peripheral benzodiazepine receptor (PBR), a marker of inflammation. Despite its widespread use, the radiation burden associated with 11C-(R)-PK11195 in humans is not known. To examine this, we performed dynamic whole-body imaging with PET and 11C-(R)-PK11195 in healthy humans. Five healthy male volunteers were scanned with PET and 11C-(R)-PK11195, using a dynamic whole-body imaging protocol. An organ-specific method was used to measure accumulated radioactivity in source organs, and residence times were calculated as areas under the curve of time-activity curves expressed as percentage of injected radioactivity. Residence times were used as input for OLINDA/EXM 1.0 software to model the equivalent organ doses and the effective dose for the 70-kg man. After intravenous injection of 11C-(R)-PK11195, radioactivity accumulated in organs rich in TSPO as well as routes of excretion: the hepatobiliary system and the urine. The mean effective dose was 4.8 µSv/MBq according to International Commission on Radiological Protection (ICRP) Publication 60 and 5.1 µSv/MBq according to ICRP Publication 103, and the highest equivalent organ doses were observed in the kidneys (14.0 µSv/MBq), spleen (12.5 µSv/MBq) and small intestine (12.2 µSv/MBq). Imaging of TSPO with PET using 11C-(R)-PK11195 is associated with modest radiation exposure, similar in magnitude to most other 11C-labelled PET tracers, suggesting feasibility of 11C-(R)-PK11195 imaging in clinical human studies involving multiple scans in the same subjects per year.

DOI: 10.1007/s00259-009-1298-3

6 Figures and Tables

05010020102011201220132014201520162017
Citations per Year

142 Citations

Semantic Scholar estimates that this publication has 142 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Hirvonen2009HumanBA, title={Human biodistribution and radiation dosimetry of 11C-(R)-PK11195, the prototypic PET ligand to image inflammation}, author={Jussi Hirvonen and Anne Roivainen and Jere R. Virta and Semi Helin and Kjell N{\aa}gren and Laura L Ekblad}, journal={European Journal of Nuclear Medicine and Molecular Imaging}, year={2009}, volume={37}, pages={606-612} }