Study Rationale: Parkinson’s disease (PD) is characterized by a prodromal phase long before someone presents with the clinical features of PD. During this phase, there are progressive biological changes occurring such as loss of dopamine cells which if accurately measured can help us identify people at risk sooner. Imaging markers such as radiolabeled AV133 have been used to quantify dopamine cell loss in brains of people with PD. AV133 is being evaluated as a marker of dopamine cell loss in people who are at risk for PD but have not developed clinical features of PD. In this study, we will utilize a new investigational high-resolution positron emission tomography (PET) camera called NeuroEXPLORER. We will compare the performance of AV133 between a high and a conventional resolution PET camera to understand if high resolution camera can help detect dopamine loss sooner. We will also evaluate if NeuroEXPLORER can improve visualization of smaller areas of the brain not well demarcated on standard PET camera.
Hypothesis: We hypothesize that a high-resolution PET camera will allow for earlier detection of dopamine changes in people at risk for PD and will be more sensitive to changes over time compared to the standard resolution PET camera.
Study Design: We will include approximately twenty-five people at risk for Parkinson’s disease categorized as Prodromal Parkinson’s Disease. We will recruit from the ongoing Parkinson’s Progression Markers Initiative (PPMI) study and its ongoing sub study that is evaluating the performance of AV133 in prodromal PD. Participant undergoing AV133 imaging in PPMI will be imaged using both a high and a conventional resolution PET camera. The imaging will be completed at baseline, 12 months, and 24 months. We will use uniformly collected clinical and biological information to see how they compare with the imaging results over time.
Impact on Diagnosis/Treatment of Parkinson’s disease: If successful, the imaging approach with high resolution camera has the potential to refine early diagnostic imaging enabling us to detect dopamine cell loss sooner. The high-resolution imaging can also improve our understanding of involvement of smaller nuclei in brains of people at risk for PD and how it relates to different clinical and biological markers. The findings will also facilitate more precise assessment of disease progression and response to medications aimed to slow down the disease progression.
Next Steps for Development: Future efforts will focus on the integration of high-resolution camera systems to enhance the sensitivity and quantitative accuracy of nuclear imaging in PD. Incorporating high-resolution imaging systems into ongoing and future studies will be a step towards establishing standardized biomarkers and enhancing the clinical trial landscape.