WEKO3
-
RootNode
アイテム
Correction for Radiolabeled O-Methyl Metabolite in Human Brain
https://repo.qst.go.jp/records/72104
https://repo.qst.go.jp/records/7210486c52139-e43b-4d53-9636-3dbcf37b24d6
Item type | 会議発表用資料 / Presentation(1) | |||||
---|---|---|---|---|---|---|
公開日 | 2016-12-22 | |||||
タイトル | ||||||
タイトル | Correction for Radiolabeled O-Methyl Metabolite in Human Brain | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
資源タイプ | conference object | |||||
アクセス権 | ||||||
アクセス権 | metadata only access | |||||
アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
著者 |
Matsubara, Keisuke
× Matsubara, Keisuke× Ito, Hiroshi× Ikoma, Yoko× Okada, Maki× Masanobu, Ibaraki× Nakamura, Kazuhiro× Yamaguchi, Hiroshi× Suhara, Tetsuya× Kinoshita, Toshibumi× 松原 佳亮× 伊藤 浩× 生駒 洋子× 岡田 真希× 茨木 正信× 中村 和浩× 山口 博司× 須原 哲也 |
|||||
抄録 | ||||||
内容記述タイプ | Abstract | |||||
内容記述 | Objectives: Dopamine synthesis rate, one of the presynaptic functions of the central dopaminergic system, can be measured by positron emission tomography (PET) measurement with L-[β-11C]DOPA [1]. The radiolabeled O-methyl metabolite of L-[β-11C]DOPA in peripheral organ, L-[β-11 C]O-methyl-DOPA (L-[β-11C]OMD), suggested to penetrate the blood-brain barrier (BBB). Thus, L-[β- 11C]OMD may affect tissue radioactivity measured by PET and the endogenous dopamine synthesis rate estimated by kinetic analyses. However, the influence of L-[β-11C]OMD in the living tissue for the kinetic analyses has not been investigated in detail. In the present study, to evaluate the influence of L-[β-11C]OMD on the tissue time-activity curve (TAC) with L-[β-11C]DOPA PET, the metabolite correction was applied to tissue TACs acquired from healthy volunteers. Methods: The metabolite correction method proposed by Kumakura et al. in [18F]FDOPA PET study [2] was employed. In this method, component for O-methyl metabolite in the tissue TAC is estimated by compartmental analysis with two kinds of arterial input function for L-[β-11C]DOPA and L-[β-11 C]OMD, and TAC in occipital cortex as a reference region with no irreversible binding. TAC in each brain region for L-[β-11C]DOPA PET studies with ten healthy volunteers [1] was corrected by using the estimated L-[β-11C]OMD TAC. This method assumes the distribution of O-methyl metabolite is uniform around the brain [3]. The endogenous dopamine synthesis rate (Ki) was estimated by Gjedde-Patlak plot analysis with the arterial input function and the metabolite-corrected TAC. The Ki was also estimated from the non-corrected TAC. For comparison to conventional analysis, relative influx constant (kref) was also estimated by Gjedde-Patlak plot analysis using TAC in occipital cortex, regarded as reference tissue input function. Data of 29 – 64 min and 29 – 89 min were used for linear regression in Gjedde-Patlak plot analysis. Results: Calculated OMD component had only a marginal effect on tissue TAC (fraction of area under curve (AUC) of L-[β-11C]OMD TAC in putaminal TAC: 9.4 ± 2.1 %). Ki with no metabolite corrected TAC correlated significantly to Ki with the metabolite correction (p < 0.001, r = 0.99 (29 – 64 min), p < 0.001, r = 0.99 (29 – 89 min)), and Ki were overestimated in all brain regions with no metabolite correction, see Figure A. kref also correlated to Ki with the metabolite correction, as shown in Figure B (p < 0.001, r = 0.99 (29 – 64 min), p < 0.001, r = 0.99 (29 – 89 min)). Conclusion: The results suggest that the influence of the O-methyl metabolite L-[β-11C]OMD to tissue TAC and kinetic parameters in L-[β-11C]DOPA PET is marginal. This finding is accounted for by low fraction of L-[β-11C]OMD in plasma in case of L-[β-11C]DOPA, in contrast with high fraction of O-methyl metabolite for [18F]FDOPA. The results also suggest the net endogenous dopamine synthesis rate can be determined without the metabolite correction in case of L-[β-11C]DOPA, not same as [18 F]FDOPA. Reference [1] Ito H., et al., 2006, Nucl. Med. Commun. 27, 723-731 [2] Kumakura Y., et al., 2005, J. Cereb. Blood Flow Metab. 25, 807-819 [3] Doudet D.J., et al., 1991, J. Cereb. Blood Flow Metab. 11, 726-734 Note - image will be printed in black & white |
|||||
会議概要(会議名, 開催地, 会期, 主催者等) | ||||||
内容記述タイプ | Other | |||||
内容記述 | The Ninth International Symposium on Functional Neuroreceptor Mapping of the Living Brain | |||||
発表年月日 | ||||||
日付 | 2012-08-10 | |||||
日付タイプ | Issued |
Share
Cite as
Matsubara, Keisuke, Ito, Hiroshi, Ikoma, Yoko, Okada, Maki, Masanobu, Ibaraki, Nakamura, Kazuhiro, Yamaguchi, Hiroshi, Suhara, Tetsuya, Kinoshita, Toshibumi, 松原 佳亮, 伊藤 浩, 生駒 洋子, 岡田 真希, 茨木 正信, 中村 和浩, 山口 博司, 須原 哲也, 2012, Correction for Radiolabeled O-Methyl Metabolite in Human Brain.
Loading...