[18F]-MFBG Versus [123I]-MIBG and [18F]-PE2I in PD vs. MSA and DLB vs. AD

Study Rationale:

This prospective study, to be conducted in two centers (UZ Leuven and UZ Gent), aims to validate cardiac [18F]-MFBG PET in distinguishing Parkinson's disease (PD) from multiple system atrophy (MSA-P) and differentiating dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). Both PD and DLB, caused by alpha-synuclein deposits (Lewy bodies), exhibit not only nigrostriatal dopaminergic deficits but also early peripheral changes in myocardial norepinephrine (NE) innervation. These defects can be visualized and quantified using NE transporter tracers. [18F]-MFBG was developed several years ago with high-yield production and has already been employed in multiple centers worldwide, mainly in the context of imaging neuroendocrine tumors. [18F]-MFBG offers logistical, technical, and pharmacological advantages, including faster scanning, high spatial resolution, and improved quantification compared to the existing method using [123I]-MIBG SPECT.

Participant Population:

The study will include 28 healthy volunteers (CON), of which 3 will participate in [18F]-MFBG PET dosimetry (part 1) and 25 in the main study for optimization/age-dependence of cardiac [18F]-MFBG parameters (part 2). In part 3, 40 PD, 15 MSA-P, 15 DLB, and 15 AD patients with biomarker-confirmed diagnoses will be included. Total: 113 subjects.

Intervention:

All subjects will undergo three examinations in the main work packages (parts 2 and 3) dynamic cardiac [18F]-MFBG PET, with dynamic [123I]-MIBG SPECT as a comparator, as well as cerebral [18F]-PE2I PET.

Endpoints:

Primary: Non-inferiority in discriminating populations using [18F]-MFBG; Secondary: effect size, relationship between myocardial uptake and cerebral dopamine active transporter (DAT) changes, autonomic dysfunction, regional myocardial variation.

Secondary:

• Determine the effect size (ES) of the reduction in myocardial uptake of [18F]-MFBG in PD and DLB compared to [123I]-MIBG SPECT and [123I]-MIBG planar scintigraphy.
• Identify any significant correlation between the reduction in myocardial uptake of [18F]-MFBG in PD and DLB and the reduction in [18F]-PE2I binding in early to moderate disease stages.
• Assess the relationship between the reduction in myocardial uptake of [18F]-MFBG in PD and DLB and measures of autonomic dysfunction.
• Examine the regional pattern of reduced [18F]-MFBG uptake in PD/DLB compared to controls, with an endpoint considered met if different regional segment scores are evident between PD/MSA-P or DLB/AD or subtypes of PD.

Inclusion criteria

• Healthy Controls:

• Voluntary written informed consent.
• Use of highly effective methods of birth control.
• Age between 18 and 85 years.
• Good health based on medical history, physical examination, clinical laboratory tests, and urinalysis.
• No history or evidence of major neurological, internal, or psychiatric disorders.
• Normal structural MRI scan for subjects < 60 years or minor lesions for subjects >= 60 years.
• Parkinson's Disease:

• Age 45-85 years.
• Clinically established PD based on Movements Disorder Society diagnostic criteria.
• Disease duration since onset of motor symptoms: 5 years or longer for one group and less than 5 years for another.
• Previous abnormal [18F]-FE-PE2I PET or [123I]-FP-CIT SPECT scan.
• Ability to understand the patient information brochure and provide written informed consent.
• Multiple System Atrophy - Parkinsonian Variant:

• Age 45-85 years.
• Clinically established or clinically probable MSA-P based on MDS diagnostic criteria.
• Previous abnormal [18F]-FE-PE2I PET or [123I]-FP-CIT SPECT scan.
• Ability to understand the patient information brochure and provide written informed consent.
• Dementia Due to Alzheimer's Disease:

• Age 50-85 years.
• Diagnosis of probable AD with evidence of the AD pathophysiological process.
• Ability to understand the patient information brochure and provide written informed consent.
• Dementia with Lewy Bodies:

• Age 50-85 years.
• Diagnosis of probable DLB.
• Previous abnormal [18F]-FE-PE2I PET or [123I]-FP-CIT SPECT scan.
• Ability to understand the patient information brochure and provide written informed consent.

Exclusion criteria

• Healthy controls:

• Major diseases that may interfere with the investigations.
• Evidence of cognitive impairment.
• History or evidence of psychiatric disease.
• Use of illicit drugs or history of drug or alcohol abuse.
• Chronic medication interfering with cardiac neuronal norepinephrine transporter (NET) or [18F]-FE-PE2I imaging.
• Exposure to ionizing radiation > 1 mSv in other research studies within the last 12 months.
• Contraindication for MRI scanning.
• Claustrophobia or inability to tolerate confinement during PET-MRI scanning.
• Unwillingness to avoid strenuous physical activity.
• Lack of understanding of the study procedures.
• Pregnancy or breastfeeding.
• Lack of agreement to communicate incidental findings to the general practitioner.
• Abnormal Allen test or lidocaine hypersensitivity/allergy for subjects willing to undergo arterial sampling.
• Parkinson's Disease:

• Neuropsychiatric diseases other than PD.
• Major internal medical comorbidity, especially diabetes or heart disease.
• White matter lesion load on FLAIR Fazekas score 2 or higher or other relevant MRI abnormalities.
• History of alcohol or drug abuse.
• Previous participation in research studies involving ionizing radiation.
• Contraindications for MR.
• Claustrophobia or inability to tolerate confinement during PET scanning.
• Unwillingness to avoid strenuous physical activity.
• Lack of understanding of the study procedures.
• Pregnancy or breastfeeding.
• Lack of agreement to communicate incidental findings to the general practitioner.
• Anticoagulant therapy.
• Multiple System Atrophy - Parkinsonian Variant:

• Same as for Parkinson's disease.
• Dementia Due to Alzheimer's Disease:

• Same as for Parkinson's disease.
• Dementia with Lewy Bodies:

• Same as for Parkinson's disease.