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The way neurosurgeons treat complicated brain disorders has changed as a result of Gamma Knife radiosurgery. Without requiring open surgery, clinicians can cure deep-seated or multiple brain lesions with this non-invasive, extremely precise type of radiation therapy. The treatment of numerous brain metastases and the use of fractionated Gamma Knife radiosurgery for massive arteriovenous malformations (AVMs) are two significant uses of this technology.

Gamma Knife in Multiple Metastases of the Brain
Knowing Brain Metastases

Tumours that spread to the brain from cancers in other body areas, like the lungs, breast, kidneys, or skin (melanoma), are known as brain metastases. These are some of the most prevalent adult brain tumours. Patients frequently arrive with many metastases that impair their quality of life and neurological abilities.
Gamma Knife: Why?
Earlier, surgery or whole brain radiation therapy (WBRT) were the available therapeutic options. Long-term adverse effects like memory loss and cognitive impairment are linked to WBRT, though. Gamma Knife radiosurgery offers a targeted substitute.

- Precision: In a single session, it can treat several metastases.
- Minimally invasive: No need for stitches, scalpels, or hospitalisation.
- Cognitive preservation: Prevents WBRT’s wide brain radiation.
- Repeatable: May be applied more than once in the event that new metastases develop.
Signals
- Usually, patients with 1–10 brain metastases are considered suitable candidates.
- Typically, tumours less than 3–4 cm react the best.
- Patients who have deep tumour location or medical comorbidities prevent them from undergoing surgery.
Results
In comparison to WBRT, studies have demonstrated better quality of life preservation, reduction in neurological symptoms, and improved local tumour control rates.
Understanding Large Arteriovenous Malformations (AVMs) via Fractionated Gamma Knife Radiosurgery
An abnormal network of veins and arteries in the brain that interferes with normal blood flow is known as an arteriovenous malformation (AVM). Because they increase the risk of seizures, brain haemorrhage, and progressive neurological impairments, large AVMs are very deadly.

Treating Large AVMs creates Difficulties
- Because of its size and deep location, surgical resection is frequently dangerous.
- If the AVM is sufficiently big, using a conventional gamma knife in a single high-dose session could result in radiation damage.
Fractionated Gamma Knife Radiosurgery: What is it?
Delivering the entire radiation dose in several smaller sessions (fractions) compared to one is known as fractionated radiosurgery. This method allows the AVM veins to gradually close while lowering the possibility of harming nearby healthy tissue.

Benefits
- Safety: Reduces the negative effects of radiation on big lesions.
- Effectiveness: Minimises problems while achieving progressive AVM obliteration.
- Customisable: The dosage and fractions can be changed according to the patient’s condition, AVM size, and location.
Procedure for Treatment
- To map the AVM, the patient has an MRI/angiography.
- Precise software is used to plan the radiation dose.
- Multiple sessions (e.g., two to five fractions) are used for providing treatment.
- The abnormal vessels eventually close off over the course of two to three years, reducing the chance of further bleeding.
Results
- Excellent alternative for large or complex AVMs not appropriate for surgery.
- Compared to single-session high-dose therapy, long-term studies have demonstrated good obliteration rates with fewer adverse effects.
In conclusion
In modern neurosurgery, Gamma Knife radiosurgery has become a vital technique. It provides a precise, non-invasive treatment that maintains neurological function and quality of life for individuals with numerous brain metastases. When surgery or single-session treatment are risky, fractionated Gamma Knife offers a safer and more efficient option for patients with big AVMs.
Patients with complicated brain disorders that were previously thought to be treatable now have hope because to this technology, which is the ideal fusion of safety, accuracy, and innovation.
Sources:
- https://pubmed.ncbi.nlm.nih.gov/28681759/
- https://med.virginia.edu/neurosurgery/services/gamma-knife/disorders-treated/arteriovenous-malformations-avm/gamma-knife-surgery-for-large-avms/
- https://journals.lww.com/neur/fulltext/2017/65040/dose_fractionated_gamma_knife_radiosurgery_for.30.aspx
- https://pubmed.ncbi.nlm.nih.gov/27903180/
- https://journals.lww.com/neur/fulltext/2017/65040/fractionated_gamma_knife_radiosurgery_for_large.5.aspx
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FAQ’s
How does Gamma Knife work?
Gamma Knife uses 192–201 precisely focused beams of gamma rays that converge at a single target point in the brain. This high dose of radiation damages the DNA of abnormal cells, stopping their growth or causing them to shrink, while minimizing exposure to nearby healthy tissue.
Is Gamma Knife a surgery?
No, Gamma Knife is not a traditional surgery. It is a non-invasive outpatient procedure performed without any incision, stitches, or general anesthesia in most cases.
What conditions can be treated with Gamma Knife?
Gamma Knife is commonly used for:
Brain tumors (benign and malignant)
Metastatic brain lesions
Arteriovenous malformations (AVMs)
Trigeminal neuralgia
Acoustic neuromas (vestibular schwannomas)
Pituitary tumors
Certain functional disorders (like tremors)
Is Gamma Knife painful?
The procedure is generally painless. Patients may feel mild pressure while the head frame (if used) is applied or may experience slight discomfort from anesthesia injections, but the treatment itself is not painful.
How long does the procedure take?
Depending on the condition and treatment plan, Gamma Knife may take 30 minutes to 3 hours. Most patients go home the same day.
What are the possible side effects?
Common side effects are usually mild and temporary, including:
Headache
Nausea
Fatigue
Mild scalp swelling or tenderness at the frame site
Rarely, some patients may experience delayed radiation effects such as brain swelling or radiation necrosis.
When can the patient return to normal activities after Gamma Knife?
Most patients can return to their normal routine within 24–48 hours after the procedure.
You may feel mild fatigue for a few days.
Follow-up imaging is usually required after 1 year.
How effective is Gamma Knife?
Gamma Knife has a high success rate and has been used worldwide for decades. Its effectiveness depends on the condition treated, size and location of the lesion, and overall patient health. In many cases, it offers results comparable to open surgery with fewer risks.
Can Gamma Knife be repeated if needed?
Yes, in some cases Gamma Knife treatment can be repeated if the disease recurs or if new lesions develop.
Is Gamma Knife safe?
Yes. Gamma Knife is considered one of the safest and most precise forms of radiosurgery, with millions of patients treated globally and extensive clinical data supporting its use.
Who is eligible for Gamma Knife treatment?
Eligibility depends on factors such as:
Size and location of the lesion
Overall health and age
Whether open surgery is too risky
A neurosurgeon and radiation oncologist will decide if Gamma Knife is the best option for you.
What happens before the procedure?
A detailed MRI or CT scan is performed to map the brain.
A lightweight head frame or mask is used for accuracy.
Your doctors plan the radiation dose and target areas using specialized software.
Will I need anesthesia?
Local anesthesia is given if a head frame is used.
General anesthesia is usually not required, except for children or patients unable to remain still.
What is the cost of Gamma Knife in India?
Costs vary depending on hospital, city, and condition treated. On average, Gamma Knife in India ranges from ₹1.5 lakh to ₹4.5 lakh. It is usually more affordable compared to treatment in Western countries. At AIIMS Delhi, it is much more affordable around ₹75,000 which makes it affordable for the patients in need.
Where can I get Gamma Knife treatment in Delhi?
AIIMS Delhi is one of the leading centres for Gamma Knife in India.
AIIMS uses the latest Gamma Knife Perfexion system.
It has successfully treated thousands of patients for brain tumors, blood vessel problems, and even eye cancers.
The treatment is done by expert neurosurgeons such as Dr. Deepak Agrawal and team.
Clinic timings for Gamma Knife OPD at AIIMS Delhi: Monday & Friday, 8:00 AM – 9:00 AM.
Cost is around ₹75,000 and is subsidized compared to private hospitals.
What is the complete process of the Gamma Knife?
The whole procedure is usually done in one day:
- Consultation & Planning – Doctors review your scans and decide the treatment.
- Head Frame/Mask – A lightweight frame or mask is placed to keep your head still.
- Imaging – MRI/CT scans are done to locate the exact target.
- Treatment Planning – Specialists plan the dose and direction of radiation.
- Gamma Knife Treatment – You lie on the machine; painless radiation beams treat the target (30 mins–3 hrs).
- Recovery & Discharge – The frame is removed, and most patients go home the same day.
- Follow-up – MRI after a few months to check results.
What formalities do I have to complete prior to getting the date of GK?
Before you get a treatment date, you need to complete a few steps:
- OPD Registration – Visit the Neurosurgery OPD (Gamma Knife clinic at AIIMS, Mon & Fri 8–9 AM) and register.
- Consultation with Doctor – Meet the neurosurgeon who will check your reports, MRI/CT scans, and medical history.
- Investigations – Sometimes fresh MRI/CT or blood tests are needed for treatment planning.
- Medical Fitness – Basic checks like blood pressure, sugar, heart condition, etc.
Financial/Insurance Approval –
- If using Ayushman Bharat or government schemes, you need approval papers.
- If self-paying, you will be given the estimated cost (~₹75,000 at AIIMS).
- Consent & Admission Slip – Once doctors confirm you are fit and formalities are done, you sign the consent form.
- Treatment Date Allotment – A date is given for your Gamma Knife procedure.
What formalities do I have to complete after getting the date of GK?
Once you receive your Gamma Knife date, you’ll need to do a few simple things before the procedure:
- Admission Process – Report to AIIMS on the morning of your procedure and complete admission at the Neurosurgery ward/Daycare.
- Paperwork – Carry your OPD slip, MRI/CT films, blood test reports, admission slip, and ID proof. If you are covered under Ayushman Bharat/insurance, keep those approval papers ready.
- Consent Forms – You (or a family member) will sign consent for the procedure and anesthesia.
- Medical Check-up – Doctors will check your BP, sugar, heart rate, and do a quick physical exam.
- Fasting – Usually, you will be asked to not eat or drink for 6 hours before the procedure.
- Pre-Procedure Prep – An IV line may be put, and medicines (sedation/antibiotics if needed) are given.
- Treatment – You are then taken to the Gamma Knife room for frame/mask placement, imaging, and treatment.
After the procedure, you’ll be observed for a few hours and most patients are discharged the same day or next morning.
What investigations to be done?
Urea & creatinine
Should I come fasting?
No, You can have light breakfast.
In case of HT/DM should take my medicines?
Yes, you can take the medicine and then come for the treatment.