1. Gemma Roberts - Alzheimer's Society Clinical Fellow
My name is Gemma Roberts and I am a nuclear medicine physicist - a type of healthcare scientist specialising in medical imaging using radioactive tracers, which produce signals that can be detected by special scanners. This method can help us to see how particular areas of the body are working and detect if there is something unusual, indicating a disease.
I previously worked in the NHS for 9 years doing a mixture of clinical work and research in lots of different areas including testing a new type of radioactive implant for treating prostate cancer, treating liver tumours with tiny radioactive spheres and installing a PET-CT scanner that can track lung tumour motion. In 2016 I was delighted to be awarded an Alzheimer's Society healthcare professional training fellowship, which offers the chance to apply my skills to try to improve dementia diagnosis and to develop as a researcher within the Institute of Neuroscience at Newcastle University.
What is my project about?
My project is about improving certain types of medical scan used to diagnose dementia with Lewy bodies. These scans use radioactive tracers to give information on whether specific nerve cells (neurons) have been damaged by the Lewy bodies, which are abnormal protein clumps that build up in the brain and other parts of the nervous system in Lewy body disease. The two scans I am working on are a brain scan (called FP-CIT) and a heart scan (called cardiac MIBG). I am investigating these scans and seeing how best to use the data so that they will be as useful as possible for early diagnosis when a person is at the Mild Cognitive Impairment (MCI) stage. This stage is diagnosed when a person's symptoms are not severe enough to interfere significantly with their everyday activities and quality of life.
We have a clinical study at Newcastle University called SUPERB, which is recruiting people who appear to have MCI due to Lewy bodies (MCI-LB) or MCI due to Alzheimer's disease (MCI-AD). Alzheimer's disease is the biggest cause of dementia but symptoms can overlap with Lewy body disease. This means that clinicians may wrongly diagnose someone with Alzheimer's disease when they actually have dementia with Lewy bodies. We are investigating whether these scans using radioactive tracers are able to distinguish between people with MCI due to Lewy body disease and people with MCI due to Alzheimer's disease.
For both scans, MCI-AD should give a normal result and MCI-LB should show reduced tracer signal because Lewy body disease is known to damage the nerve pathways in the brain and the nerves that supply the heart. However, there is lots of variation between people and this makes the diagnosis complicated. This is why I am testing ways to improve the scan data in this project.
"We are investigating whether these scans using radioactive tracers are able to distinguish between people with MCI due to Lewy body disease and people with MCI due to Alzheimer's disease."
We have so far scanned about 50 people with either MCI-AD or MCI-LB and 15 people without MCI as part of the SUPERB study. Everyone has both heart and brain scans at the beginning of the study. My clinical colleagues are following them up each year for up to five years to see how they are doing and check whether they develop dementia.
I am also testing a more advanced three dimensional scan method called SPECT-CT using scans from real patients and computer models. So far I have done simulations of very simple scans (for example a cylinder filled with radioactive tracer!) using a computer and am testing them to make sure the simulation matches the real scan. Once I know this stage is OK I will then go on to simulate scans using more realistic physical models and computer models of the heart and brain and then finally simulate scans using patient data from the SUPERB study. I will be able to compare the two scans thoroughly and find out how we should be scanning patients and how we should analyse the image data to get the best results possible.
How will this project help people with dementia?
If we can diagnose people with MCI correctly then this will be very useful in the future as more drugs to treat the specific diseases (Alzheimer's and Lewy body disease) begin to be developed and tested. Previous studies suggest that any treatment to stop dementia developing will need to be given early on, so we will need tests to show whether people have early stage Lewy body or early stage Alzheimer's disease.
Accurate diagnosis at an earlier stage is also good news for people currently living with dementia as there is more time to get treatment and make plans for the future. If patients have Lewy body disease this can then be documented to make sure they are not given medication that could be harmful, for example anti-psychotics. We think that the scans I am working on will form an important part of the picture when making a diagnosis at the MCI stage, which is why it's crucial to make sure they are as accurate as possible.
"Accurate diagnosis at an earlier stage is also good news for people currently living with dementia as there is more time to get treatment and make plans for the future"
Several of my family members were diagnosed with dementia at a later stage when they were not really able to understand or come to terms with it, so I will always be grateful to the Alzheimer's Society for the opportunity to use my experience in medical imaging to try to improve early diagnosis.