Program offered option to surgery for brain tumour patients when launched in 1997

This June, the BC Cancer Agency’s Stereotactic Radiation Therapy Program – which provides leading-edge treatment for patients with brain tumours – celebrates 10 years of providing stereotactic radiosurgery (SRS) to B.C. patients.

To mark the anniversary, the provincial program is getting ready to introduce new state-of-the-art technology – which eliminates having to secure a metal frame to a patient’s head during treatment. B.C. is the first province in Canada to obtain the $500,000 BrainLab frameless system, thanks to the generosity of BC Cancer Foundation donors.

With the current technique, a head ring is screwed into a patient’s skull by a neurosurgeon, and therapists – using a three-dimensional mapping system – accurately position a patient on the radiation therapy machine treatment bed. With the frameless system patients wear a mask instead, and radiation therapists use special digital x-ray imaging and software which provides images of the skull to reposition patients precisely and safely.

“The head frame is uncomfortable,” says Dr. Michael McKenzie, a radiation oncologist who is co-director of the SRS program with Dr. Brian Toyota. “It increases the trauma patients face while undergoing treatment. The new system will greatly improve the experience for our patients.”

The exact repositioning is necessary because typically brain tumours treated with SRS are very small – less than four centimeters – and surrounded by other critical structures. Not all such tumours are cancerous, in fact many are benign. However they are typically difficult to remove surgically such as arteriovenous malformations (abnormal connections between arteries and veins of the brain), acoustic neuromas (tumours which press against auditory nerves), and small pituitary adenomas (abnormal growths in the pituitary gland at the base of the brain).

SRS involves delivering focused radiation therapy (x-ray beams) to the site of the tumour in a single treatment. SRS is not suitable for some brain tumours, particularly those which are large and not well-defined. However, in carefully selected cases, SRS can be an alternative to surgery.

“While all procedures have some risks, stereotactic radiosurgery is relatively non-invasive and has been successful at reducing disability, neurological complications, and mortality for brain tumour patients,” says Dr. Brian Toyota, a neurosurgeon.

“It is a one-day treatment, and usually a single treatment is necessary. Patients come into the BC Cancer Agency in the morning and go home in the evening. Frequently patients return to their jobs and lives without missing a beat.”

Mark Sachs, a 46 year-old Vancouver lawyer, was diagnosed with an acoustic neuroma – a benign growth in the inner ear canal – in 2004. “I noticed that I couldn’t hear as well in my right ear, which I found out later was the result of a 2 centimetre tumour pressing on the nerves in the ear,” says Mark. “Left untreated it would have continued to grow and put pressure on my brain.”

After a consultation with a neurosurgeon, Mark opted for SRS. “Surgery would have meant weeks of convalescing, and time off work. The stereotactic radiation therapy was done in a day, and it really wasn’t any worse than a dentist’s office visit,” says Mark. He was back at work in a couple of days

Since the program began 10 years ago, more than 600 patients have been treated. In 1998, 39 patients received treatment, with that number increasing to 87 in 2006.

“Here in B.C. we’ve continued to stay ahead of the wave, adopting new proven practices early,” says McKenzie. In 2002, the BC Cancer Agency purchased a M3 microleaf collimator which allows therapists to conform radiation beams to the shape of small tumours. “That was a significant milestone,” says McKenzie, “Tumours come in all shapes, and with this new technology we’re able to manipulate the beams to the shape of the tumour, leading to more targeted treatment.”

The program is a collaboration among the BC Cancer Agency, the Division of Neurosurgery at Vancouver General Hospital, and surgeons across the province. A team of neurosurgeons, radiation oncologists, neuro-radiologists, and medical physicists meet regularly to determine which patients would most benefit from the treatment.

The team has also contributed to research to improve the delivery of SRS for acoustic neuroma patients. One important study followed 34 patients to understand why some patients retained their hearing, and others lost their hearing following treatment. The study showed that by avoiding radiation exposure of the cochlea – a part of the inner ear – patients might preserve hearing post-treatment.

The BC Cancer Agency, an agency of the Provincial Health Services Authority, is committed to reducing the incidence of cancer, reducing the mortality from cancer, and improving the quality of life of those living with cancer. It provides a comprehensive cancer control program for the people of British Columbia by working with community partners to deliver a range of oncology services, including prevention, early detection, diagnosis and treatment, research, education, supportive care, rehabilitation and palliative care.

*Please note: Patients who have had SRS are also available to comment from Nanaimo and Kelowna.

Contact:
Papinder Rehncy
Public Relations Coordinator