Parkinson’s disease is a common progressive neurodegenerative disorder, which is primarily diagnosed on the basis of clinical features and response to dopaminergic therapy. In the early stages of the disease it can be difficult to distinguish from other causes of parkinsonism (e.g. drug induced parkinsonism, vascular parkinsonism, Multiple System Atrophy etc), and from other tremulous disorders such as Essential Tremor. As opposed to Parkinson’s disease many of these conditions have normal presynaptic nigrostriatal function, which can be assessed by functional radiotracer based PET imaging. An accurate early diagnosis of Parkinson’s Disease is crucial from a prognostic, therapeutic and neuroprotective perspective. Unfortunately, this imaging modality is not currently available in Western Australia nor is it widely available in other parts of the country. The WA PET service, in collaboration with R.A.P.I.D. laboratories, Medical Technology and Physics, SCGH, have experience in developing new tracers for functional imaging, using positron emission tomography (PET) technology. PET scans are very sensitive and allow the quantitation of functional processes.
We propose to radiolabel a dopamine transporter agent with a PET radionuclide in order to assess the dopamine transporter function in the brain, a measure of presynaptic dopaminergic integrity. Most PET agents are produced in a cyclotron, which are a scarce and expensive resource (there is only 1 cyclotron in Western Australia). The PET radionuclide we propose to use, Gallium-68 (68Ga), is however unique, as it comes in a generator, which lasts for 1 year. This will allow for easy access and is relatively inexpensive compared to cyclotron produced PET radionuclides.
Our project therefore aims to radiolabel a dopamine transporter agent, TRODAT, with Gallium-68. Multiple labelings will be performed to optimize the technique, under a range of conditions. Extensive testing of this product will be performed. At the end of the project we hope to have a product suitable for testing in human clinical trials.