RT Journal Article SR Electronic T1 Influence of TSPO Genotype on 11C-PBR28 Standardized Uptake Values JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1320 OP 1322 DO 10.2967/jnumed.112.118885 VO 54 IS 8 A1 Karmen K. Yoder A1 Kwangsik Nho A1 Shannon L. Risacher A1 Sungeun Kim A1 Li Shen A1 Andrew J. Saykin YR 2013 UL http://jnm.snmjournals.org/content/54/8/1320.abstract AB 11C-PBR28 binds to the high-affinity state of the translocator protein 18 kDa (TSPO). A single-nucleotide polymorphism (rs6971) within the human TSPO gene determines the affinity state of the TSPO. The rs6971 genotype determines whether individuals express the high-, low-, or mixed-affinity phenotype of TSPO. The rs6971 genotype corresponds to in vivo 11C-PBR28 binding, as measured quantitatively by total volume of distribution. However, it is not known whether standardized uptake value (SUV) can detect differences in brain 11C-PBR28 uptake by TSPO genotype. Methods: Thirty-two older adults (71.8 ± 7.94 y old) underwent 11C-PBR28 PET scanning; rs6971 genotype was imputed after genomewide genotyping. SUV was extracted for several brain regions. The sample included 19 C/C carriers (high-affinity phenotype), 12 T/C carriers (mixed-affinity), and 1 T/T carrier (low-affinity) for rs6971. Results: SUV was 30% lower in T/C subjects than in C/C subjects. Conclusion: The results indicate that brain 11C-PBR28 SUV is sensitive to TSPO genotype.