Gamma Knife milestone: 1000 patients
01 May 2025
Peter Mac has marked a major milestone, treating the 1000th patient using Victoria’s first Gamma Knife.
The Gamma Knife is not actually a knife at all — but a form of stereotactic radiosurgery that uses up to 192 beams of radiation precisely focused on a target area deep inside the brain.
1000th patient Sylvia Theodorou (pictured above with her treatment team) received her treatment today for lung cancer that has spread to the brain, with two lesions targeted in the treatment session.
"The team has been seriously great," Sylvia said following her treatment. "I have absolutely no complaints and that is the truth."
Since launching the service in 2021, Peter Mac’s Gamma Knife has treated patients with a range of illnesses, from cancer and benign tumours to neurological and vascular conditions.
“This is a significant moment for our team, and for the many patients and families who have trusted us to care for them,” said Dr Neda Haghighi, clinical lead of the Gamma Knife Service.
“Reaching 1000 patients is not just about numbers — it reflects the growing confidence in this highly specialised treatment and the positive impact it’s having on people’s lives.”
The treatment is incredibly accurate, sparing surrounding healthy tissue and often completed in a single outpatient session.
“For many of our patients, Gamma Knife offers an option where traditional surgery would be too risky or simply not possible,” Dr Haghighi says.
“We can treat tumours located deep in the brain or close to critical structures, and deliver results with minimal disruption to the patient’s life.”
One of the most common conditions treated is brain metastases — cancer that has spread to the brain from elsewhere in the body. The Gamma Knife has proven to be a highly effective tool for controlling these lesions, often allowing patients to continue with systemic cancer treatments while preserving their quality of life.
“We’ve seen incredible outcomes — people able to return to work, to care for their families, to live without pain,” Dr Haghighi said.
“For patients with trigeminal neuralgia, for example, a condition that causes debilitating facial pain, Gamma Knife can offer fast and long-lasting relief without the need for invasive procedures.”
Peter Mac’s Gamma Knife program brings together a multidisciplinary team of radiation oncologists, neurosurgeons, radiation therapists, medical physicists, nurses and allied health professionals, who collaborate to assess each case and deliver carefully individualised care.
“We’ve built something really special here — a team that is not only technically outstanding but also deeply compassionate,” said Dr Haghighi.
“We work closely with referring clinicians across Victoria and beyond, and it’s incredibly rewarding to see what’s possible when we bring together expertise and the right technology.”
Looking ahead, the team is focused on continuing to expand access and pushing the boundaries of what’s possible with Gamma Knife treatment.
“This is just the beginning,” said Dr Haghighi. “We’re committed to innovation, to research, and to making this life-changing treatment available to every patient who could benefit from it.”
The milestone of 1000 patients is more than a number — it’s a testament to innovation, collaboration, and a commitment to delivering world-class care where it matters most.
Peter Mac’s Gamma Knife is the first of its kind to be installed in Victoria and only the third in Australia, was co-funded equally by the Victorian Government and through the generous donations to the Peter MacCallum Cancer Foundation.
In 2004, Linden Kelleher was diagnosed with a 3.7cm acoustic neuroma — a benign brain tumour that grows on the nerve responsible for hearing and balance.
“It was life-changing,” she recalls.
“I had a four-year-old at home, a husband going through a nervous breakdown, and suddenly I was facing brain surgery.”
Acoustic neuromas can grow slowly but, if untreated, they can press on surrounding brain structures. Linden underwent surgery at St Vincent’s Hospital in Sydney, which successfully removed the tumour.
But the recovery was gruelling.
“I lost all hearing in one ear and had no balance. I had to learn to walk again. It was horrendous,” she explains.
For nearly two decades, MRIs showed no sign of recurrence, but 18 years later, Linden began experiencing numbness on her face.
Scans confirmed the tumour had returned.
“It was a shock. A cell must have been left behind all those years ago.”
She consulted multiple specialists. While one recommended immediate surgery, another advised watchful waiting.
Linden chose to wait — for 18 months, the tumour remained stable. But in early 2024, it began to grow again.
Linden was determined to avoid another invasive surgery and, given the size, Gamma Knife was now a viable option.
In New South Wales, Gamma Knife treatment is not publicly funded and only available at a private facility, so she made the decision to travel to Melbourne to have her treatment at Peter Mac.
The treatment itself involved a single one-hour session, with a head frame used to keep her completely still.
“I was scared — radiation in the brain is confronting — but it was the right choice for me. Compared to surgery, it was like night and day,” Linden explains.
“The staff were phenomenal. The process was calm.
“I managed to turn the trip into a bit of a food tour with my brother and daughter and I was absolutely fine to do that after treatment.”
Now, nearly a year later, scans show the tumour has shrunk by a millimetre. “It’s more than we hoped for. I’m back at work, back at the gym — living life.”
Through her role in the Acoustic Neuroma Association Australia, Linden now shares her experience to support others navigating the condition.
We’re not doctors, but we help people make informed decisions. It’s vital that patients know their options from those who have been there,” she says.
May is also Brain Cancer Awareness Month.