An 86-year-old woman with cognitive impairment and left hemiparesis underwent 18F-THK5351 PET 4 months before her death. In addition to “normal” off-target binding in the basal ganglia, abnormal accumulation was observed along the pyramidal tract and around the right basal ganglia as ring-shaped uptake that overlapped a gadolinium-enhanced lesion. Postmortem pathological examination revealed that she had glioblastoma multiforme with associated gliosis, in which monoamine oxidase B (MAO-B) activity is increased. In vitro autoradiography of the corresponding lesion demonstrated specific binding of 18F-THK5351, which was blocked by an MAO-B–selective ligand. Thus, 18F-THK5351 PET may reflect glioblastomas and associated gliosis by binding to MAO-B.
From the *Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology; and
Departments of †Neurology and
‡Neuropathology, Brain Bank for Aging Research, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.
Received for publication December 18, 2018; revision accepted January 25, 2019.
Conflicts of interest and sources of funding: This study was supported by a research grant from Novartis Pharma and JSPS KAKENHI grants JP16H06277, JP17K09813, and JP18K15655. None declared to all authors.
CME/CE disclosure: 18F-THK5351 can be used for research purposes.
Correspondence to: Jun Toyohara, PhD, Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakae-cho, Itabashi-ku, Tokyo 173-0015, Japan. E-mail: firstname.lastname@example.org.
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