Department of Neurology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital.
From the Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology.
Clin Nucl Med. 2022 Jul 1;47(7):e489-e495. doi: 10.1097/RLU.0000000000004272. Epub 2022 May 12.
18F-THK5351 PET estimates the concentrations of monoamine oxidase B (MAO-B) that are preferentially located in astrocytes and can be used to visualize and quantify ongoing astrogliosis. To study images of astrogliosis in neurological disorders, it is essential to understand the detailed binding sites of 18F-THK5351 as the MAO-B ligand under normal conditions. In this study, we examined the detailed distribution pattern of 18F-THK5351 in the healthy brain by comparing 18F-THK5351 uptake between subjects taking and not taking the MAO-B inhibitor.
Ten healthy controls (HCs: 67.4 [SD, 15.1] years) and 4 patients with Parkinson disease taking the MAO-B inhibitor underwent 18F-THK5351 PET. The uptake ratio index (URI) was defined to quantify 18F-THK5351 uptake, using the cerebellum as a reference region. The cerebellar URI was set to zero.
For HCs, regions with URI ≥1 were preferentially observed in the following order: the striatum, globus pallidus, thalamus, hypothalamus, amygdala, periaqueductal gray, substantia nigra, medulla, hippocampus, and pons. The peak URI values in the corresponding regions were 2.93, 2.47, 2.12, 2.04, 1.84, 1.68, 1.67, 1.37, 1.20, and 1.11, respectively. For all patients with Parkinson disease taking the MAO-B inhibitor, the URI values in all these regions were significantly decreased (Z score >2) and were reduced from 60.4% to 99.9%, compared with HCs.
This study presented the detailed distribution pattern of 18F-THK5351 in HCs and suggests that 18F-THK5351 uptake largely reflects MAO-B concentrations under normal conditions.
18F-THK5351 PET 可估计优先存在于星形胶质细胞中的单胺氧化酶 B（MAO-B）浓度，可用于可视化和量化持续的星形胶质细胞增生。为了研究神经退行性疾病中的星形胶质细胞增生图像，了解 MAO-B 配体 18F-THK5351 在正常情况下的详细结合位点至关重要。在这项研究中，我们通过比较服用和未服用 MAO-B 抑制剂的受试者之间的 18F-THK5351 摄取，检查了健康大脑中 18F-THK5351 的详细分布模式。
10 名健康对照者（HCs：67.4[标准差，15.1]岁）和 4 名服用 MAO-B 抑制剂的帕金森病患者接受了 18F-THK5351 PET。采用小脑作为参考区，定义摄取比值指数（URI）来量化 18F-THK5351 的摄取。小脑 URI 设为零。
对于 HCs，URI≥1 的区域按以下顺序优先观察到：纹状体、苍白球、丘脑、下丘脑、杏仁核、导水管周围灰质、黑质、髓质、海马和脑桥。相应区域的峰值 URI 值分别为 2.93、2.47、2.12、2.04、1.84、1.68、1.67、1.37、1.20 和 1.11。对于所有服用 MAO-B 抑制剂的帕金森病患者，与 HCs 相比，所有这些区域的 URI 值均显著降低（Z 评分>2），降低了 60.4%至 99.9%。
本研究介绍了 18F-THK5351 在 HCs 中的详细分布模式，并表明 18F-THK5351 的摄取在正常情况下很大程度上反映了 MAO-B 浓度。
