title: Visualising neuroinflammation in post-stroke patients: a comparative PET study with the TSPO molecular imaging biomarkers [11C]PK11195 and [11C]vinpocetine.
abstract: With the main objective of comparing the prospective diagnostic power of two 11C-labelled molecular imaging biomarkers with affinity for TSPO and used for the visualisation of activated microglia after a stroke, we measured with positron emission tomography (PET) in four post-stroke patients the regional brain uptake and binding potential of [11C]vinpocetine and [11C]PK11195. Percentage standard uptake values (%SUV) and binding potential (BPND) were used as outcome measures. The total peak brain uptake value and average global brain uptake value were higher for [11C]vinpocetine than for [11C]PK11195. The regional %SUV values were significantly higher for [11C]vinpocetine than for [11C]PK11195 in the hemispheres as well as in almost all standard brain regions. The %SUV values of [11C]vinpocetine were higher in the peri-infarct zone than in the ischaemic core, however, the difference did not prove to be significant. There was basically no difference in %SUV values between the ischaemic core and the peri-infarct zone for [11C]PK11195. The BPND values for [11C]vinpocetine were higher in all standard regions than those for [11C]PK11195, but the difference was not significant between them. The BPND values of [11C]vinpocetine were higher in the peri-infarct zone than in the ischaemic core, however, the difference did not prove to be significant. A comparative analysis of the two ligands indicates that [11C]vinpocetine shows a number of favourable characteristics over [11C]PK11195, but to demonstrate that it may serve as a prospective molecular imaging biomarker of microglia activation in post-stroke patients, further studies are required.
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Stockholm, Sweden. balazs.gulyas@ki.se
authors.forename: Balazs
authors.initials: B
authors.lastname: Gulyas
authors.forename: Miklos
authors.initials: M
authors.lastname: Toth
authors.forename: Adam
authors.initials: A
authors.lastname: Vas
authors.forename: Evgeni
authors.initials: E
authors.lastname: Shchukin
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kostulas
authors.forename: Jan
authors.initials: J
authors.lastname: Hillert
authors.forename: Christer
authors.initials: C
authors.lastname: Halldin
mesh_terms: D000368:Aged; D001665:Binding Sites; D015415:Biomarkers / Q000378:metabolism; D002250:Carbon Radioisotopes; D004660:Encephalitis / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry; D008297:Male; D008875:Middle Aged; D057054:Molecular Imaging; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000737:chemistry; D018079:Receptors, GABA / Q000378:metabolism*; D020521:Stroke / Q000000981:diagnostic imaging*; D014748:Vinca Alkaloids / Q000138:chemical synthesis / Q000737:chemistry; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002250:Carbon Radioisotopes; D007546:Isoquinolines; D019275:Radiopharmaceuticals; D018079:Receptors, GABA; C499229:TSPO protein, human; D014748:Vinca Alkaloids; C013983:vinpocetine; C037850:PK 11195