title: Short term vs. long term test-retest reproducibility of ¹²³I-ADAM for the binding of serotonin transporters in the human brain.
abstract: Previous brain imaging studies have demonstrated a seasonal difference of serotonin transporter (SERT) binding in the human brain. However, the results were somewhat contradictory. We conducted test-retest study with single photon emission computed tomography (SPECT) with ¹²³I-ADAM as ligand in 28 healthy subjects. Ten of the subjects were studied within 1 month, whereas 18 were randomly assigned to be studied over a period of up to 1 year. The primary measure was the specific uptake ratio (SUR). Regions of interest included the midbrain, thalamus, putamen and caudate. The intra-class correlation coefficient (ICC) was 0.52-0.94 across different brain regions over 1 month, whereas the ICC was -0.24-0.63 over a 1-year period. The 1-month variability ranged from 6.5 ± 5.1% to 12.5 ± 10.6% across different brain regions, and the 1-year variability ranged from 16.5 ± 9.6% to 41.9 ± 35.5%. The Kruskal-Wallis test revealed a significant difference of variability across months. The Wilcoxon Signed Ranks Test showed the SUR between test-retest scans was of borderline significance. Curve fitting, using a 4th degree polynomial model, revealed a significant circadian correlation between the variability and interval of test-retest measurements. Our findings demonstrate the test-retest reproducibility of ¹²³I-ADAM in different time periods and suggest that circadian variation of SERT levels in the human brain might exist.
authors.affiliation: Department of Psychiatry, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan.
authors.forename: Ju-Wei
authors.initials: JW
authors.lastname: Hsu
authors.affiliation: Department of Nuclear Medicine, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan.
authors.forename: Shyh-Jen
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: Department of Psychiatry, Taoyuan Armed Forces General Hospital, Taipei, Taiwan.
authors.forename: Chun-Lung
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Psychiatry, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan.
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Hsieh
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan.
authors.forename: Jiing-Feng
authors.initials: JF
authors.lastname: Lirng
authors.affiliation: National Research Institute of Chinese Medicine, Taipei, Taiwan.
authors.forename: Yuh-Chiang
authors.initials: YC
authors.lastname: Shen
authors.affiliation: Institute of Nuclear Energy Research, Lung-Tan, Taoyuan, Taiwan.
authors.forename: Mei-Hsiu
authors.initials: MH
authors.lastname: Liao
authors.affiliation: Department of Psychiatry, Taipei Veterans General Hospital & National Yang Ming University, Taipei, Taiwan. Electronic address: c520608@ms64.hinet.net.
authors.forename: Yuan-Hwa
authors.initials: YH
authors.lastname: Chou
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000187:drug effects*; D001931:Brain Mapping; D002928:Cinanserin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011485:Protein Binding / Q000187:drug effects; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D018709:Statistics, Nonparametric; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult
chemical_list: C413491:2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine; D019275:Radiopharmaceuticals; D050486:Serotonin Plasma Membrane Transport Proteins; D002928:Cinanserin