Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-2035, USA.
J Nucl Med. 2010 Jan;51(1):145-9. doi: 10.2967/jnumed.109.068064. Epub 2009 Dec 15.
As a PET biomarker for inflammation, translocator protein (18 kDa) (TSPO) can be measured with an (18)F-labeled aryloxyanilide, (18)F-N-fluoroacetyl-N-(2,5-dimethoxybenzyl)-2-phenoxyaniline ((18)F-PBR06), in the human brain. The objective of this study was to estimate the radiation absorbed doses of (18)F-PBR06 based on biodistribution data in humans.
After the injection of (18)F-PBR06, images were acquired from head to thigh in 7 healthy humans. Urine was collected at various time points. Radiation absorbed doses were estimated by the MIRD scheme.
Moderate to high levels of radioactivity were observed in organs with high densities of TSPO and in organs of metabolism and excretion. Bone had low levels of radioactivity. The effective dose was 18.5 muSv/MBq.
The effective dose of (18)F-PBR06, compared with other (18)F radioligands, was moderate. This radioligand had negligible defluorination, as indirectly assessed by bone radioactivity. Doses to the gallbladder wall and spleen may limit the amount of permissible injected radioactivity.
作为炎症的 PET 生物标志物，转位蛋白（18 kDa）（TSPO）可以用（18）F 标记的芳氧基苯胺（（18）F-N-氟乙酰基-N-（2,5-二甲氧基苄基）-2-苯氧基苯胺（（18）F-PBR06）在人脑中进行测量。本研究的目的是根据人体的生物分布数据估算（18）F-PBR06 的吸收剂量。
在 7 名健康人中注射（18）F-PBR06 后，从头部到大腿采集图像。在不同时间点收集尿液。通过 MIRD 方案估算辐射吸收剂量。
在 TSPO 密度高的器官和代谢及排泄器官中观察到中等至高水平的放射性。骨骼放射性水平较低。有效剂量为 18.5 μSv/MBq。
与其他（18）F 放射性配体相比，（18）F-PBR06 的有效剂量适中。这种放射性配体几乎没有脱氟作用，这可以通过骨骼放射性间接评估。胆囊壁和脾脏的剂量可能会限制允许注射的放射性物质的量。
