- Email: [email protected]
D3 receptor by haloperidol in normal volunteers using [18F] fallypride
NRM2010 abstracts — Poster presentations
Poster Presentation No.: P119
S197
Methodology
Occupancy of striatal and extrastriatal dopamine D2/D3 receptor by haloperidol in normal volunteers using [18F] fallypride Su Jin Kim, Hyun Soo Park, Jong Jin Lee, Byung Suk Moon, Ji Sun Kim, Bung Chul Lee, Yu Kyung Kim, Sang Eun Kim Department of Nuclear Medicine, Seoul National University Bundang Hospital, South Korea Objective: Haloperidol is a one of widely used typical antipsychotics. With high-affinity of [18F] fallypride, it became possible to quantify extrastriatal dopamine receptors. Therefore, we performed [18F] fallypride PET studies in healthy subjects treated with haloperidol to examine the occupancy of striatal and extrastriatal dopamine receptors. To characterize the effect of oral haloperidol, its striatal and extrastriatal D2/D3 receptor binding was characterized under steady-state conditions. Method: [18F]fallypride PET were obtained in 3 healthy subjects under steady-state haloperidol treatment at 24 h after the last dose of 0.5 or 3 mg. A 3-h PET scan with [18F]-fallypride (0.1 mCi/kg) was carried out on each subject. Brain regions-of-interest were identified and drawn using coregistered MR images. Binding potential (BP) was analyzed using simplified reference tissue model using cerebellum as reference. Receptor occupancy after haloperidol treatment was defined as percentage reduction of BP relative to the individual baseline BP estimates.
Result: Binding potential value varied from 34.5 to 0.18 in three healthy subjects. The highest values were found in the putamen, while the lowest values were in the frontal and occipital cortex. 3-mg dose of haloperidol occupied 60.2% of striatal D2/D3 receptors (55.3% in putamen, 62.8% in caudate, and 62.8% in nucleus accum) and 54.4% of extrastriatal D2/D3 receptor (varied from 20.6% in frontal cortex to 74% in amygdala). In 0.5-mg dose, haloperidol exhibit 20.7% occupancy in striatal receotor and 22.8% in extrastriatal receptor. Although the mean occupancy of haloperidol was similar between striatal and extrastriatal, wide range of occupancy was observed in extrastrital region (5.8% to 39.1%).
S198
NRM2010 abstracts — Poster presentations
Conclusion: This is the first imaging study using a high-affinity D2/D3-ligand to determine D2/D3-receptor occupancy at extrastriatal sites in normal volunteers with haloperidol under steady-state conditions. The result of this preliminary study might be helpful to understand haloperidol-induced extrapyramidal symptoms. doi:10.1016/j.neuroimage.2010.04.160
Poster Presentation No.: P119
S197
Methodology
Occupancy of striatal and extrastriatal dopamine D2/D3 receptor by haloperidol in normal volunteers using [18F] fallypride Su Jin Kim, Hyun Soo Park, Jong Jin Lee, Byung Suk Moon, Ji Sun Kim, Bung Chul Lee, Yu Kyung Kim, Sang Eun Kim Department of Nuclear Medicine, Seoul National University Bundang Hospital, South Korea Objective: Haloperidol is a one of widely used typical antipsychotics. With high-affinity of [18F] fallypride, it became possible to quantify extrastriatal dopamine receptors. Therefore, we performed [18F] fallypride PET studies in healthy subjects treated with haloperidol to examine the occupancy of striatal and extrastriatal dopamine receptors. To characterize the effect of oral haloperidol, its striatal and extrastriatal D2/D3 receptor binding was characterized under steady-state conditions. Method: [18F]fallypride PET were obtained in 3 healthy subjects under steady-state haloperidol treatment at 24 h after the last dose of 0.5 or 3 mg. A 3-h PET scan with [18F]-fallypride (0.1 mCi/kg) was carried out on each subject. Brain regions-of-interest were identified and drawn using coregistered MR images. Binding potential (BP) was analyzed using simplified reference tissue model using cerebellum as reference. Receptor occupancy after haloperidol treatment was defined as percentage reduction of BP relative to the individual baseline BP estimates.
Result: Binding potential value varied from 34.5 to 0.18 in three healthy subjects. The highest values were found in the putamen, while the lowest values were in the frontal and occipital cortex. 3-mg dose of haloperidol occupied 60.2% of striatal D2/D3 receptors (55.3% in putamen, 62.8% in caudate, and 62.8% in nucleus accum) and 54.4% of extrastriatal D2/D3 receptor (varied from 20.6% in frontal cortex to 74% in amygdala). In 0.5-mg dose, haloperidol exhibit 20.7% occupancy in striatal receotor and 22.8% in extrastriatal receptor. Although the mean occupancy of haloperidol was similar between striatal and extrastriatal, wide range of occupancy was observed in extrastrital region (5.8% to 39.1%).
S198
NRM2010 abstracts — Poster presentations
Conclusion: This is the first imaging study using a high-affinity D2/D3-ligand to determine D2/D3-receptor occupancy at extrastriatal sites in normal volunteers with haloperidol under steady-state conditions. The result of this preliminary study might be helpful to understand haloperidol-induced extrapyramidal symptoms. doi:10.1016/j.neuroimage.2010.04.160