Details

Autor(en) / Beteiligte

• DeLorenzo, Christine
• Gallezot, Jean-Dominique
• Gardus, John
• Yang, Jie
• Planeta, Beata
• Nabulsi, Nabeel
• Ogden, R Todd
• Labaree, David C
• Huang, Yiyun H
• Mann, J John
• Gasparini, Fabrizio
• Lin, Xin
• Javitch, Jonathan A
• Parsey, Ramin V
• Carson, Richard E
• Esterlis, Irina

Titel

In vivo variation in same-day estimates of metabotropic glutamate receptor subtype 5 binding using [11C]ABP688 and [18F]FPEB

Ist Teil von

• Journal of cerebral blood flow and metabolism, 2017-08, Vol.37 (8), p.2716-2727

Ort / Verlag

London, England: SAGE Publications

Erscheinungsjahr

2017

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Positron emission tomography tracers [11C]ABP688 and [18F]FPEB target the metabotropic glutamate receptor subtype 5 providing quantification of the brain glutamatergic system in vivo. Previous [11C]ABP688 positron emission tomography human test–retest studies indicate that, when performed on the same day, significant binding increases are observed; however, little deviation is reported when scans are >7 days apart. Due to the small cohorts examined previously (eight and five males, respectively), we aimed to replicate the same-day test–retest studies in a larger cohort including both males and females. Results confirmed large within-subject binding differences (ranging from −23% to 108%), suggesting that measurements are greatly affected by study design. We further investigated whether this phenomenon was specific to [11C]ABP688. Using [18F]FPEB and methodology that accounts for residual radioactivity from the test scan, four subjects were scanned twice on the same day. In these subjects, binding estimates increased between 5% and 39% between scans. Consistent with [11C]ABP688, mean absolute test–retest variability was previously reported as <12% when scans were >21 days apart. This replication study and pilot extension to [18F]FPEB suggest that observed within-day binding variation may be due to characteristics of mGluR5; for example, diurnal variation in mGluR5 may affect measurement of this receptor.