[<sup>18</sup>F]NOS PET Brain Imaging Suggests Elevated Neuroinflammation in Idiopathic Parkinson’s Disease
Robert K. Doot,
Anthony J. Young,
Ilya M. Nasrallah,
Reagan R. Wetherill,
Andrew Siderowf,
Robert H. Mach,
Jacob G. Dubroff
Affiliations
Robert K. Doot
Division of Nuclear Medicine Imaging and Therapy, Department of Radiology in the Perelman, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Anthony J. Young
Division of Nuclear Medicine Imaging and Therapy, Department of Radiology in the Perelman, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Ilya M. Nasrallah
Division of Nuclear Medicine Imaging and Therapy, Department of Radiology in the Perelman, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Reagan R. Wetherill
Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Andrew Siderowf
Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Robert H. Mach
Division of Nuclear Medicine Imaging and Therapy, Department of Radiology in the Perelman, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Jacob G. Dubroff
Division of Nuclear Medicine Imaging and Therapy, Department of Radiology in the Perelman, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
Neuroinflammation is implicated as a key pathologic mechanism in many neurodegenerative diseases and is thought to be mediated in large part by microglia, native phagocytic immune cells of the CNS. Abnormal aggregation of the protein α-synuclein after phagocytosis by microglia is one possible neuropathophysiological mechanism driving Parkinson’s disease (PD). We conducted a human pilot study to evaluate the feasibility of targeting the inducible isoform of nitric oxide synthase using the [18F]NOS radiotracer to measure neuroinflammation in idiopathic PD. Ten adults consisting of 6 PD patients and 4 healthy controls (HC) underwent one hour of dynamic [18F]NOS positron emission tomography (PET) brain imaging with arterial blood sampling. We observed increased [18F]NOS whole brain distribution volume (VT) in PD patients compared to age-matched healthy controls (p p = 0.72). These findings suggest elevated oxidative stress, a surrogate marker of inflammation, is present in early-stage idiopathic PD and indicate that [18F]NOS PET imaging is a promising, non-invasive method to measure neuroinflammation.
