DOCUMENT

Headlines 7 The bulk of the tumour is sent to the pathology lab to confirm the cancer diagnosis. A small amount is provided to Dr Park for research. Before this was possible, Dr Park and Dr Correia had to figure out how best to preserve the tissue. They needed to devise a culture medium to keep the cells alive and work out the best way to transfer from the operating room to the lab. (Non-diseased brain cells are extremely sensitive to being cut off from the blood supply, and quickly die.) “There was nothing out there to guide us,” Dr Park explains. “We had to invent how to do this, and it’s exciting because now we’re putting what we found into practice.” Dr Park says he knows of few other places in the world where scientific and surgical teams have forged such successful partnerships. Their established routine will involve a second trip too. The first one, as described, is a rapid retrieval of non- cancerous tissue that’s been taken en route to the deep- seated tumour. The second trip comes after Dr Correia has resected (cut out) the tumour itself, which takes more time. Tumour tissue isn’t so sensitive to blood supply loss, so the retrieval process doesn’t require a sprint. Having access to this tissue has allowed Dr Park to carry out research that’s very important to brain cancer patients. Funded by a Neurological Foundation grant of $277,768, he’s looking at the long-term side effects of radiation on the brain. Radiation oncologists always try to limit radiation reaching beyond the tumour but it’s impossible to avoid this altogether, and often some low-level radiation will affect the surrounding normal brain tissue. Little is known about the long-term impact, such as radiation-induced cognitive decline and dementia. Dr Park applies low-dose radiation to the living human brain tissue and documents changes, both immediate and over the period of a month. This is roughly as long as they can keep the tissue alive. Dr Park says having this live human brain tissue is a game-changer. For the first time, they can investigate the effects of radiation in intact human brain tissue. This provides much more information than would be possible by examining the various cell populations in isolation. Dr Park knows finding a way to limit radiation damage is important to patients. This was confirmed at a recent national brain tumour conference in New Zealand, where long-term side effects, such as dementia or ataxia (problems with co-ordinating movement) were the subject of many patients' questions. Despite being extremely grateful for surviving the brain tumour, it was clear they had concerns about the negative impacts from radiation therapy. Interestingly, the research may also have benefits for the study of dementia from other causes. At present, it’s impossible to tell when the decline into dementia actually starts. In contrast, if human brain tissue receives a dose of radiation, the precise starting point is known. This allows researchers to look for the first signs of change. Dr Park says his research won’t solve problems directly but it will shed light on processes that as yet have remained a mystery. For example, if Dr Park finds there’s a protein change at the transmission site of nerve impulses (the synapse) that could lead to a deterioration inmemory, then other researchers could investigate whether any drugs can prevent the change. Both Dr Park and Dr Correia want to thank the Neurological Foundation for supporting their work. Over time, they’ve received several Neurological Foundation grants and scholarships which they describe as “project-enabling and career-defining.” Dr Correia is also the co-director of the Centre for Brain Research Neurosurgery Research Unit and a key member of the Hugh Green Biobank where tissue samples from close to 300 tumours are kept. Also, Dr Park, together with brain tumour researchers and clinicians across New Zealand, formed the first national brain tumour society (NANOS – NZ Aotearoa Neuro-oncology Society). Through NANOS, they’re working towards establishing a national brain cancer registry. The aim is to share research findings and best clinical practice across the country. Read more at neurological.org.nz/news Dr Susan Li, a newly-awarded First Fellow (see p18), is Secretary for the New Zealand Aotearoa Neuro-Oncology Society (NANOS). Her mentors are Dr Thomas Park and Professor Mike Dragunow. Click here for the longer version Dr Jason Correia