At a glance
Gamma Knife Radiosurgery is a non-surgical brain treatment that uses hundreds of precisely aimed beams of gamma radiation to destroy abnormal tissue without cutting into the skull.
Each individual beam carries very little energy and passes harmlessly through the surrounding brain. Where all the beams converge at a single point, however, the combined radiation dose is high enough to damage the DNA of abnormal cells and stop them from growing or shrink them over weeks and months. The skull is never opened, and no general anaesthetic is required for most patients.
Medical Condition
Gamma Knife is used when a target inside the brain is too small, too deep, or in too delicate a location to reach safely with conventional surgery, or when a patient's general health makes open surgery too risky.
- Brain tumours, both primary (originating in the brain) and metastatic (spread from cancer elsewhere in the body)
- Acoustic neuroma (a non-cancerous tumour on the nerve that controls hearing and balance)
- Meningioma (a usually slow-growing tumour on the protective lining of the brain)
- Arteriovenous malformation, or AVM (an abnormal tangle of blood vessels in the brain that can bleed)
- Trigeminal neuralgia (a severe facial pain condition caused by a misfiring nerve)
- Pituitary adenoma (a benign tumour on the gland at the base of the brain that regulates hormones)
- Selected cases of epilepsy (recurrent seizures) that have not responded to medication
- Recurrent or residual tumour after conventional surgery or radiotherapy
Gamma Knife is generally not suitable in certain situations, and your neurosurgeon and radiation oncologist will assess these carefully.
- Tumours or lesions larger than about three to four centimetres, where the radiation field would damage too much surrounding brain tissue
- Multiple scattered lesions that cannot all be treated in a single session without excessive total radiation
- Conditions that require tissue to be removed and examined, not just destroyed
- Active infection inside the skull
- Pregnancy, unless the risk of not treating is life-threatening
Risks & Complications
Gamma Knife is generally well tolerated, but radiation to any part of the brain can cause side effects, and some complications may appear months after treatment.
- Fatigue and headache in the days immediately after treatment, which usually resolve on their own
- Scalp discomfort or mild hair thinning at the entry points of the frame pins used to fix the head
- Nausea, particularly if the treated area is near structures that control balance
- Temporary swelling (oedema) of brain tissue near the treated site, which can cause new or worsened neurological symptoms
- Radiation necrosis (death of healthy brain tissue near the treatment zone), which can cause lasting neurological problems in a small number of patients
- Worsening of existing symptoms in the weeks after treatment before improvement begins, sometimes called a "radiation reaction"
- For acoustic neuromas specifically, a risk of reduced hearing or facial numbness
- For trigeminal neuralgia treatment, a risk of facial numbness or altered sensation
- Incomplete response, meaning the tumour or lesion does not shrink as expected and further treatment is needed
- In rare cases, a second tumour caused by radiation exposure many years later
Preparation & Procedure
Preparation for Gamma Knife usually begins days to weeks before the session and involves several steps that your care team will coordinate.
On the day itself, you usually stop eating and drinking from midnight or from a set number of hours before your appointment. Blood thinners, aspirin-type medications, and certain supplements are typically paused in the days before, following your doctor's specific instructions. Avoiding alcohol in the days prior and stopping smoking before the procedure are also standard recommendations, as both affect how blood vessels and healing tissue respond to radiation.
Before the session, the team will run imaging tests to map the exact target. These usually include a high-resolution MRI (magnetic resonance imaging), and sometimes a CT scan or cerebral angiogram (an X-ray of the brain's blood vessels) depending on the condition being treated. These images are loaded into planning software so the radiation team can calculate exactly where each beam needs to go.
On the day of the procedure, the steps typically follow this order:
- A lightweight metal frame called a stereotactic head frame is attached to the skull using four small pins under local anaesthetic (numbing injections at each pin site). Children and some adults may receive sedation instead.
- High-resolution imaging is repeated with the frame in place so the planning team can calculate precise coordinates.
- A treatment plan is designed by the neurosurgeon and medical physicist, sometimes taking an hour or more for complex cases.
- The patient lies on a sliding bed that moves into the Gamma Knife unit. The frame locks into the machine to ensure the head cannot move.
- Radiation is delivered. This phase can last from a few minutes to a few hours, depending on the size, number, and location of the targets. The patient remains still but feels nothing during delivery.
- The frame is removed, the pin sites are dressed, and the patient moves to a recovery area.
Aftercare
Most patients go home on the same day or the morning after, which is one of the practical advantages of Gamma Knife over open brain surgery. Recovery looks different depending on the condition treated, the patient's baseline health, and how the brain responds to radiation in the weeks that follow.
- You are monitored for a few hours after the frame is removed, and the pin-site wounds are checked before discharge.
- Headache, scalp soreness, and mild swelling at the pin sites are common in the first day or two and are managed with simple pain relief.
- Most patients can resume light daily activity within a day or two, but strenuous exercise and heavy lifting are usually avoided for at least a week.
- Driving restrictions apply until your doctor confirms it is safe, which depends on your neurological condition and local regulations.
- Steroids (anti-inflammatory medication) are sometimes prescribed for a short period if swelling of brain tissue is anticipated.
- Follow-up MRI or CT scans are scheduled at intervals of several months, typically starting around three months after treatment, to assess the response of the tumour or lesion.
- The full effect of Gamma Knife on a tumour or AVM may take one to three years to become visible on imaging, so patience with the follow-up schedule is essential.
- Report any new or worsening headache, vision changes, weakness, speech difficulties, or seizures to your care team promptly.
- If the treated condition was a secreting pituitary tumour (one that produces excess hormones), hormone levels will be monitored through blood tests over time.
- Lifestyle habits such as a balanced diet, not smoking, and managing blood pressure support overall brain health during recovery.
Cost & What Determines It
Gamma Knife Radiosurgery is among the more expensive single-session brain treatments available, and the price can vary very widely between hospitals and countries because so many different factors feed into the final bill.
- Complexity of the case: treating a single small tumour in one session costs considerably less than treating multiple lesions or a large, irregularly shaped target that demands a lengthy planning and delivery process.
- Hospital class and country: a university-affiliated neuroscience centre in a high-income country carries different overhead costs from a private specialist hospital in a lower-cost country, even when the same machine model is used.
- Number of treatment sessions: some conditions, especially larger or recurring tumours, may require more than one session (hypofractionated treatment), multiplying costs.
- Pre-treatment imaging: the high-resolution MRI, and any CT or angiography required for planning, may be billed separately from the radiosurgery itself.
- Planning time: unusually complex tumour shapes or locations near critical structures require more physicist and neurosurgeon time in the planning software, and this is often reflected in the fee.
- Anaesthesia or sedation: most adults do not need general anaesthesia, but children or anxious patients who require sedation will incur additional anaesthesia fees.
- Inpatient stay: if an overnight stay is recommended, the room charge, nursing care, and meals add to the total.
- Post-treatment medication: corticosteroids (steroid tablets or injections) prescribed after the procedure are usually an additional cost.
- Follow-up scans: the MRI scans required at three months, six months, and beyond are separate expenses that extend the overall cost of care.
Hospital packages for Gamma Knife often bundle the machine time, the stereotactic frame, the treatment planning fee, and the neurosurgeon and radiation oncologist fees into a single quoted price. What is frequently billed separately includes the pre-procedure MRI or CT, anaesthesia if used, hospital room charges, post-treatment medication, and follow-up imaging. Always ask a hospital for an itemised estimate that covers both the procedure day and the expected follow-up schedule.
BPJS Kesehatan does not cover treatment received outside Indonesia, and most Indonesian private health insurance policies also exclude overseas care. Patients who travel abroad for Gamma Knife therefore typically pay out of pocket, or rely on an international health insurance policy that explicitly covers planned medical travel. Before booking travel, ask the hospital for a written cost estimate that lists every expected charge, including follow-up imaging, so that the total financial commitment is clear before any commitment is made.
Frequently Asked Questions
How many sessions of Gamma Knife Radiosurgery will I need?
Most patients need only one session, which is one of the key differences between Gamma Knife and conventional radiotherapy. For certain larger or more complex targets in the brain, the doctor may plan two to five sessions spread over a few days. Your neurosurgeon and radiation oncologist will decide the exact number after reviewing your scans and medical history.
What does Gamma Knife treatment actually feel like?
During the procedure most people feel little to nothing, as the radiation beams themselves are not felt. A lightweight frame is fitted to your head to keep it perfectly still, and some patients find this the most uncomfortable part. You will lie on a table that moves slowly into the machine, and the actual treatment can feel similar to having an MRI scan, quiet and still.
How soon will I know if the Gamma Knife treatment is working?
Changes in the treated area usually appear gradually over weeks to months, because the radiation works by slowly disrupting abnormal cell growth rather than removing tissue instantly. Your doctor will schedule follow-up MRI or CT scans at regular intervals, often starting a few months after treatment, to track how the target area is responding. Some patients notice symptom changes earlier, but the full effect can take up to a year or longer.
How much does Gamma Knife Radiosurgery cost?
The cost varies depending on the number of treatment sessions planned, the complexity of the target area in the brain, the class of hospital you choose, and the fees of the neurosurgery and oncology team involved. There are no standard figures that apply across all hospitals, so the most reliable way to get a real number is to request a written cost estimate directly from the hospital before you travel.
This page is general information, not a substitute for medical advice. Every case is different. Your doctor decides what is right for you.
