South Africa’s first and only Gamma Knife, introduced into Netcare’s Milpark Hospital through an investment by leading oncology and cancer care company, Eurolab, in 2017, has completed over 465 successful radiosurgery treatments on patients suffering from diseases or abnormalities in and around the brain.
Speaking ahead of International Brain Tumour Awareness Week which runs from 26 October to 2 November every year, Eurolab Group CEO, Lynne du Toit, says, “Gamma Knife machines are found in leading hospitals across the world. South Africa now has one machine, but too few people have access to it. We are working hard to fix this – building understanding amongst medical schemes about the benefits of radiosurgery treatment and talking to the public sector about how their patients can gain access to the Gamma Knife.”
Dr Maurizio Zorio, neurosurgeon at Milpark and one of the directors of Gamma Knife South Africa, says, “Our radiosurgery unit is a hub of excellence. We are dedicated to brain work. For patients, the treatment is easier, quicker and has fewer side effects than other older treatments.
“Radiosurgery first became widely accepted because of its success with metastatic tumors – tumors that develop in the brain due to cancer that has spread from other parts of the body. But the Gamma Knife treats many other brain conditions as well. Our unit here has treated approximately 30 different kinds of benign and malignant head pathologies since the Gamma Knife was installed.”
The patients treated to date are mostly from Johannesburg and surrounds but also from
Port Elizabeth, Bloemfontein and Pretoria East where special terminals have been installed. In these remote centres, the patient’s medical teams do the planning for the Gamma Knife surgery and the patient then travels to Milpark where the Gamma Knife team conducts the radiosurgery.
The Gamma Knife is in fact not a knife and radiosurgery does not involve any incisions. It replaces the surgeon’s scalpel with up to 192 narrow beams of radiation, generated from radioactive cobalt and targeted to pre-determined designated areas in the brain.
It is non-invasive and does not harm surrounding healthy tissue.
Radiosurgery is being used across the world to control malignant and non-malignant tumors, as well as vascular and functional disorders in the brain. Despite the surgery involving delicate brain tissue, patients are typically in and out of the hospital in a day or two. Treatment can also be done in an outpatient setting which means most patients can go home on the same day.
This game-changing machine is referred to as the gold standard of intracranial radiosurgery because of its perfect precision and good patient outcomes.
Radiation oncologist at Milpark, Dr Chris Jordaan, says, “As well as metastasis where we have achieved local control in 90% of cases, we have also had a lot of success with:
- Meningioma – a tumor that forms on membranes that cover the brain and spinal cord just inside the skull which is often not accessible with traditional surgery.
- Pituitary adenoma – a tumor that occurs in the pituitary gland which we can’t remove with traditional surgery. Here, the Gamma Knife also prevents regrowth in about 95% of patients. If the tumor secretes hormones, we can control this in about 70% of cases.
- Acoustic neuroma (or vestibular schwannoma) – a non-cancerous slow-growing tumor that develops on the main nerve leading from the inner ear to the brain which directly influences balance and hearing and can cause hearing loss. In the past, surgeons were reluctant to operate because of the risk of deafness, but the Gamma Knife has changed this.
- Trigeminal neuralgia – a chronic pain disorder that affects the trigeminal nerve. A high dose of radio therapy directed right onto the nerve has achieved and sustained pain control in the majority of cases.
Jordaan adds that, “We have also seen rarer tumours such as Glomus jugulare and Craniopharyngiomas where we have achieved a 90% control rate using the Gamma Knife. Malignant melanomas in the eye have also responded extremely well to radiosurgery.”
Dr Zorio explains that the Gamma Knife can also be used for functional neurosurgery to help patients with issues such as Parkinson’s disease and tremors. “In these instances, however, the three-person core team must expand to include a larger multidisciplinary team made up of a neurologist, a neuropsychiatrist and others. Conditions like epilepsy that have not responded to other treatment are also being considered for Gamma Knife radiosurgery.
“But, we have to be led by the science. We are not a clinical trial site, but a specialised treatment site. Other centres have big volumes of patients, are doing thousands of cases and are involved in clinical trials. We can only work on what has been proven by science.”
Dr Jordaan adds that worldwide, the epidemiology of these tumors remains poorly understood. “Data that Gamma Knife SA is collecting data will be used together with that obtained at other centres across the world to better understand brain cancers and diseases,” he says.
The first Gamma Knife was developed in 1967 by Lars Leksell, a Swedish physician and professor of neurosurgery. Today’s Gamma Knife is based on the original prototype but has benefited from more than 40 years of advancements in engineering, radiation physics, and computer imaging technology.
The team required for radiosurgery is made up of an experienced neurosurgeon, who works closely with a radiation oncologist specialising in therapeutic procedures involving radiant energy to control cancer, and a medical physicist or biophysicist. The physicist works with the doctors in dose delivery planning and also tests the Gamma Knife’s mechanical functions, verifies that the imaging and treatment planning computers are working and ensures the software is in order. The Gamma Knife itself consists of the radiation unit, the beam-focusing technology, the patient couch, an electric bed system, the control console, the frame for the patient’s head and the planning computer system.
