Vivian M. Rakoff PET Centre, Research Imaging Centre, Centre for Addiction and Mental Health CAMH, 250 College Street, Toronto, Ontario, Canada, M5T 1R8.
Mol Imaging Biol. 2013 Jun;15(3):353-9. doi: 10.1007/s11307-012-0589-4.
[(18)F]-FEPPA is a translocator protein (18 kDa, TSPO) positron emission tomography (PET) radiotracer. Radiation dosimetry was estimated from the whole body biodistribution, taking into consideration TSPO rs6971 (Ala147Thr) polymorphism.
[(18)F]-FEPPA whole body PET scans were acquired for six healthy subjects. Time-activity curves were generated from regions of interest of nine organs, from which normalized accumulated activities were calculated and thus internal dose, using OLINDA/EXM 1.1. Genotyping of rs6971, associated with high- and low-affinity [(18)F]-FEPPA binding (high-affinity binder (HAB) and low-affinity binder (LAB)), was performed.
Five subjects exhibited the C/C (HAB) allele, and the other carried the minor allele T/T (LAB). The LAB whole body biodistribution showed highest radioactivity accumulation in bladder, whereas in HABs, the spleen received the highest dose. The effective dose of the single LAB (16.3 μSv/MBq) was 23 % less than the mean of the HABs (21.0 ± 2.9 μSv/MBq). When including all subjects, the effective dose was 20.2 ± 3.0 μSv/MBq.
[(18)F]-FEPPA radiation dose is consistent with other (18)F-labeled radioligands and the Ala147Thr genotype agreed with [(18)F]-FEPPA distribution.
[(18)F]-FEPPA 是一种转位蛋白（18 kDa，TSPO）正电子发射断层扫描（PET）示踪剂。考虑到 TSPO rs6971（Ala147Thr）多态性，从全身生物分布估算了辐射剂量。
对 6 名健康受试者进行了 [(18)F]-FEPPA 全身 PET 扫描。从 9 个器官的感兴趣区生成时间-活性曲线，从中计算归一化累积活性，然后使用 OLINDA/EXM 1.1 计算内部剂量。对 rs6971 进行了基因分型，rs6971 与高亲和力 [(18)F]-FEPPA 结合（高亲和力结合物（HAB）和低亲和力结合物（LAB））和低亲和力结合物相关。
5 名受试者表现出 C/C（HAB）等位基因，而另一名受试者携带较小的 T/T（LAB）等位基因。LAB 的全身生物分布显示膀胱的放射性最强，而在 HAB 中，脾脏的剂量最高。单个 LAB 的有效剂量（16.3 μSv/MBq）比 HABs 的平均值（21.0 ± 2.9 μSv/MBq）低 23%。当包括所有受试者时，有效剂量为 20.2 ± 3.0 μSv/MBq。
[(18)F]-FEPPA 的辐射剂量与其他 [(18)F]标记的配体一致，并且 Ala147Thr 基因型与 [(18)F]-FEPPA 分布一致。
