Gamma Knife

Istanbul

Gamma Knife in Istanbul is available at 5 hospitals in the Voumed network.

Gamma Knife is a form of stereotactic radiosurgery, a highly precise way of treating targets deep inside the head without any cut, incision or general anaesthesia. Despite its name it is not a knife and involves no surgery in the usual sense. Instead, hundreds of finely focused beams of gamma radiation are aimed from many angles so that they all meet at a single point. Each beam alone is too weak to harm the tissue it passes through, but where they converge a strong, sharply shaped dose is delivered to the target while the surrounding healthy brain is largely spared. It offers a non-invasive option for tumours and other lesions that may be difficult or risky to reach with open surgery.

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At a glance

Type: non-invasive stereotactic radiosurgery for the brain and head
Used for: brain tumours, metastases, vascular malformations and certain functional disorders
Key benefit: treats deep targets with no incision and minimal effect on healthy tissue
Session: usually completed in a single day, often as a day case
Where it is used: specialised accredited radiosurgery centres abroad

What it is

Gamma Knife is a dedicated radiosurgery system that focuses gamma radiation on a precise point inside the head. The patient lies on a couch and the head is held still, either with a lightweight stereotactic frame fixed to the skull under local anaesthetic or with a custom-moulded mask. Detailed imaging, such as MRI or CT, maps the exact location and shape of the target, and a treatment plan is calculated so that the radiation matches it as closely as possible. The system then delivers the converging beams to that point. Because the precision is measured in fractions of a millimetre, it can reach areas of the brain that are hard or unsafe to operate on directly.

How it works

The principle is simple to picture. A single beam of radiation passing through the brain on its own would be weak and would affect everything along its path. Gamma Knife instead splits the dose into many beams entering from different directions, each so low that the healthy tissue it crosses is barely affected. All of these beams are aimed to cross at exactly the same spot, and where they overlap their combined energy is high enough to treat the target. The head is kept completely still during treatment so the focus point does not move. The patient feels nothing from the radiation itself, lies awake and comfortable, and can usually hear and speak with the team. A single session may last from under an hour to a few hours, depending on the size and number of targets.

What it treats and who it helps

Gamma Knife is used for a range of conditions inside the head. These include benign and malignant brain tumours, tumours that have spread to the brain from elsewhere, vestibular schwannomas (acoustic neuromas), meningiomas, pituitary tumours and arteriovenous malformations, which are abnormal tangles of blood vessels. It is also used for some functional disorders, most notably trigeminal neuralgia, a severe facial nerve pain, and certain movement disorders such as tremor. It is especially valuable for small to medium targets, for lesions located deep in the brain or close to critical structures, and for patients who are not suitable for open surgery. A specialist team reviews each case to decide whether radiosurgery, conventional surgery or another treatment is the best fit.

Benefits and what to expect

The main advantage is that effective, focused treatment is given without opening the skull, which means no surgical wound, no blood loss and a very low risk of the complications linked to open brain surgery. Most treatments are completed in a single day and many patients go home the same day and return to normal activities quickly. Because the dose falls off sharply outside the target, nearby healthy brain receives very little radiation, helping to protect important functions. Results are not always immediate: tumours often stop growing and then slowly shrink over months, while conditions such as trigeminal neuralgia may improve over weeks. The care team explains the expected timeline, arranges follow-up imaging and stays in contact to monitor progress.

Frequently asked questions

These answers are general guidance and may vary by provider. Confirm the details with the hospital you choose.

Is Gamma Knife treatment painful?

The radiation itself causes no pain and you feel nothing while it is delivered. If a stereotactic frame is used, it is attached under local anaesthetic, which may cause brief discomfort, and any mask used is simply snug rather than painful. Most patients find the session calm and tolerable.

Is it really surgery, and will my head be cut open?

No. Despite the name, there is no cutting, no incision and no opening of the skull. Gamma Knife delivers focused radiation from outside the body, which is why it is called radiosurgery rather than conventional surgery.

Is it safe, and what about healthy brain tissue?

It is a well-established and precise treatment. Each individual beam is weak and only the point where they all converge receives a strong dose, so the healthy brain the beams pass through is largely spared. As with any radiation treatment, the team reviews your case carefully and explains the specific considerations for you.

How long does treatment take and will I stay overnight?

Treatment is usually completed in a single day. The session itself can last from under an hour to a few hours, depending on the target, and many patients are able to go home the same day rather than stay overnight.

How soon will I see results?

Results develop gradually. Many tumours stop growing and then slowly shrink over months, and follow-up scans track this change. Conditions such as facial nerve pain may ease over a number of weeks. Your team will explain what to expect in your case.

Am I a candidate for Gamma Knife?

It depends on the type, size and position of the target and on your overall health. A specialist team studies your scans and medical history to decide whether radiosurgery is the most suitable option or whether another approach would work better.