Test-retest reproducibility of extrastriatal binding with 123I-FP-CIT SPECT in healthy male subjects

• Published in: Psychiatry research. Neuroimaging Vol. 258; pp. 10 - 15
• Main Authors: Matsuoka, Kiwamu, Yasuno, Fumihiko, Shinkai, Takayuki, Miyasaka, Toshiteru, Takahashi, Masato, Kiuchi, Kuniaki, Kosaka, Jun, Inoue, Makoto, Kichikawa, Kimihiko, Hasegawa, Masatoshi, Kishimoto, Toshifumi
• Format: Journal Article
• Language: English
• Published: Elsevier Ireland Ltd 30.12.2016
• Subjects: 123I-FP-CIT; Cortex; Midbrain; Reproducibility; Serotonin transporter; SPECT; Midbrain; Serotonin transporter; Reproducibility; SPECT; Cortex; 123I-FP-CIT
• ISSN: 0925-4927; 1872-7506
• DOI: 10.1016/j.pscychresns.2016.10.007

123I-labeled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (123I-FP-CIT) is used to assess striatal dopamine transporter (DAT) expression, but it can also quantify extrastriatal serotonin transporter (SERT) expressions. While FP-CIT uptake in extrastriatal regions has been quantified, no information exists on the reproducibility of the 123I-FP-CIT specific uptake ratio (SUR) in extrastriatal regions. We investigated test-retest reproducibility of 123I-FP-CIT binding in the striatum, the midbrain, and cortical regions in eight healthy male subjects. All subjects underwent two 123I-FP-CIT SPECT scans, and SUR was calculated using the cerebellum as the reference. We found good test-retest reproducibility of 123I-FP-CIT SUR in the midbrain, and in the lateral frontal/temporal cortex and combined cortical regions. The overall variability and intraclass correlation of SUR were, respectively, 4.9–7.8% and 0.90–0.96 in striatal regions, 8.6% and 0.79 in the midbrain, and 3.6–9.1% and 0.84–0.95 in the lateral frontal/temporal cortex and combined cortical regions. Our results provide evidence that 123I-FP-CIT SPECT is a valid technique for analyzing striatal DAT, as well as extrastriatal SERT in areas such as the SERT-enriched midbrain. In addition, our data suggest that 123I-FP-CIT could be used for analyzing SERT in regions with relatively low SERT expression (e.g., temporal or frontal cortices). •Reproducibility of 123I-FP-CIT binding in extrastriatal regions was examined.•Specific uptake ratio (SUR) was calculated using the cerebellum as the reference.•Good reproducibility of 123I-FP-CIT SUR was found in extrastriatal regions.•123I-FP-CIT SPECT is a valid technique for analyzing extrastriatal regions.•123I-FP-CIT SPECT can be used for analyzing striatal DAT and extrastriatal SERT.