Sunnybrook oncologists are giving new hope to individuals living with brain cancer. Using a highly targeted high-dose radiation treatment called Stereotactic Radiosurgery, Dr. Arjun Sahgal and colleagues at Sunnybrook's Odette Cancer Centre are extending quality of life for patients with brain metastases and helping them hold onto more of the brain's neurocognitive function.
Stereotactic Radiosurgery is a high-precision radiotherapy technique that allows the delivery of high doses of radiation to a focused tumour location in the brain, while significantly sparing healthy brain tissue that supports thought processes such as attention span, memory, problem- solving, decision-making and language skills. This targeted sparing of healthy tissue is even more critical for patients with brain cancer that has spread or metastasized as side effects from previous treatments when the cancer was localized has a cumulative effect.
"The management of brain metastases is more complex with emerging radiation techniques. In the past, we simply treated the whole brain with radiation with the goal to manage symptoms. We now deliver focal high dose radiation instead, to control the tumours for patients who have a limited number of metastases (typically up to four), and use whole brain radiation later, if and when they need it," says Dr. Arjun Sahgal, a radiation oncologist at Sunnybrook's Odette Cancer Centre, and international research leader in brain and spine cancers.
"The aim is to preserve the patient's memory functioning, avoid delays in chemotherapy and improve the patient's tolerability to chemotherapy given that the side effects of whole brain radiation can leave people feeling very tired. Beyond radiation we also have a targeted MRI Guided Brain Ultrasound device that we are starting to use for patients with prior radiation who need focal therapy," says. Dr. Sahgal, also an assistant professor of Radiation Oncology and Surgery in the Department of Radiation Oncology at the University of Toronto.
As testament to his leading work in this area, he and radiation oncology colleague, Dr. May Tsao of the Central Nervous System Cancer Care team at the Odette were recently honored by the European Association of Neuro-Oncology. Their publication, A Meta-Analysis Evaluating Stereotactic Radiotherapy, Whole Brain Radiotherapy or Both for Patients Presenting with a Limited Number of Brain Metastases was recognized as one of the best neuro-oncology articles of 2011 among a select group of papers by researchers from around the world, published in journals including Lancet Oncology, Cancer, Journal of Clinical Oncology, Science, Cell, and New England Journal of Medicine.
Stereotactic Radiosurgery does not remove the tumor, but distorts the DNA or genetic instructions within the tumor cells. The cells then lose the ability to reproduce and hold fluids that leads to tumor reduction or control. Because of the high-precision nature of this therapy, expertise and collaboration is vital to effective treatment and the radiation oncologists work closely with their neurosurgeon colleagues.
Sunnybrook's Odette Cancer Centre is one of only a few centres in Canada providing Stereotactic Radiosurgery for brain and spine metastases, and related Stereotactic Body Radiotherapy for the treatment of lung and liver tumours. At the Centre, radiation oncologists work closely with medical physicists who engineer precise equipment functionality, dosimetrists who carefully plan dose delivery, and radiation therapists who meticulously deliver the therapy to the patient.