Patient Guide · Gamma Knife radiosurgery
What is Gamma Knife radiosurgery?
Despite the confusing name, Gamma Knife is one of the most precise tools in neurosurgery — a form of focused radiation that treats targets in the brain without a single incision.
The science
How it works
The 200-beam principle
Two hundred individual beams of cobalt radiation are aimed at the target from different angles. Each beam is too weak to damage healthy tissue along its path, but where they all converge, the combined dose is powerful enough to achieve the desired biological effect.
Single session vs. fractions
Unlike conventional radiotherapy — which delivers small doses over many sessions — Gamma Knife delivers the entire treatment in a single day. This precision means less radiation to surrounding brain and no need for repeated hospital visits.
Indications
What it treats
Brain tumours
Both primary brain tumours and metastatic deposits — particularly when small, well-defined, and deep-seated.
Meningiomas
Benign tumours arising from the meninges; Gamma Knife can halt growth in the majority of cases.
Pituitary adenomas
Benign tumours of the pituitary gland, where focused radiation can stop hormone overproduction and control size.
Acoustic neuromas
Benign tumours of the hearing and balance nerve, where radiosurgery often preserves useful hearing.
Arteriovenous malformations
Abnormal tangles of blood vessels in the brain that carry a risk of haemorrhage; Gamma Knife gradually closes them off.
Trigeminal neuralgia
A severe facial pain disorder where a focused dose to the nerve root can provide lasting relief.
The procedure
What happens on the day
Frame fitting
In the morning, a lightweight stereotactic frame is fitted to your head under local anaesthetic, or a custom-moulded mask is made. This ensures sub-millimetre precision during treatment.
Planning scan
An MRI or CT scan is performed while you rest. The images are used to map your target in three dimensions.
Team designs the plan
Your neurosurgeon, a radiation oncologist, and a medical physicist work together. Every one of the 200 beams is shaped individually to conform exactly to your target while sparing healthy brain.
Treatment
You lie still on the treatment couch. You feel nothing — the procedure is painless. Treatment lasts from 20 minutes to over an hour, depending on the target. You go home the same day.
Most patients are home by the afternoon — there is no incision, no hospital stay, and recovery is measured in days rather than weeks.
Patience required
Results take time
Gamma Knife does not remove a tumour on the day of treatment. Its biological effects — halting cell division, closing off abnormal blood vessels — unfold over weeks to months. This can be a difficult concept when you want the problem gone immediately, but understanding the timeline helps set realistic expectations.
What to remember
Is Gamma Knife always right?
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