Acıbadem International

The Golden Standard in the treatment of brain tumours!

“Gamma Knife”

The term “Radiosurgery” has initially been used in medicine by Swedish neurosurgeon Lars Leksell. It means direction of a multitude of low energy (hence it does not sustain any damage to the brain tissue) radiation clusters to the diseased area inside the skull. These radiation clusters focus on the diseased region and direct high energy solely to this part of the brain, thereby causing a change in the tissue.
The Gamma Knife device has first been used back in 1968. Initially, its use was very limited in a few centers around world and once its therapeutic benefits were proven, it came into widespread use. Currently, it is being used in more than 300 centers around the world. Based on the figures for the year 2009, more than 500.000 patients with a variety of brain diseases have been successfully treated with the Gamma Knife. Even though LINAC systems such as the X-knife and Cyberknife are being used in the radiation of brain pathologies, currently no other device has been able to attain the sensitivity level of the Gamma Knife, nor has any other device has served such a multitude of patients.
The basis of Gamma Knife radiosurgery consists of fixing the skull with the help of a stereotactical frame, identifying the diseased area inside the skull with the help of a computer, and radiating that area with gamma radiation from 201 cobalt sources. Low energy radiation directed from each source does not sustain any damage on the healthy part of the brain, whereas the diseased area gets exposed to a high dose of radiation.
Gamma Knife may be used in AVM, brain tumours and functional diseases. The tumour to be treated should have a diameter of less than 3.5cm. For patients, this is an opportunity that does not involve any blood or knife. It is a therapeutic method which eliminates the need for anaesthesia and intensive care stay, and lasts only for couple of hours. Most of the patients can go back to their daily routines the following day.
In this day and age, patients prefer to be cured through relatively simple methods. Intense medical research is underway to make sure that patients have such an option. Because of eliminating the need to open up the skull, Gamma Knife radiosurgery fulfills the need in this regard.

Indications of Gamma Knife Radiosurgery

Since 1968, Gamma Knife is being used on an increasing number of patients around the world for a variety of indications. Gamma Knife is the “golden standard” in stereotactical radiosurgery. Until 2009, more than 500.000 patients have been treated worldwide. Acıbadem Healthcare Group’s Kozyatağı Hospital is using the Gamma Knife for the following indications.

Patients with Vascular Diseases:
Arteriovenous malformation (AVM)
Cavernoma
Galen vein aneurysm

Patients with Benign tumours:
Vestibular schwannoma
Hemangioblastoma
Meningioma
Chordoma
Pituitary gland tumours
Trigeminal schwannoma
Pineal region tumours
Craniopharyngioma

Patients with malignant tumours:
Metastasis
Ocular melanoma
Astrocytoma
Glioblastoma
Hemangiopericytoma
Glomus tumour
Nasopharynx carcinoma

Patients with Movement Disorders:
Parkinson’s disease
Essential tremor
Multiple sclerosis

Patients with Functional diseases:
Trigeminal neuralgia
Epilepsy
Chronic pain

Tumours which are found in hard to reach and deeper regions of the brain
Patients who will not be able to tolerate surgical intervention due to advanced age, medical condition and general health condition.
Patients who refuse open surgery

How does the Gamma Knife Work?
The impact of stereotactical radiosurgery on surgical tissue is similar to that of other radiotherapy methods. The Gamma Knife does not extricate the tumour or the diseased tissue, rather, it works by changing the DNA of the cells. As such, tumour cells lose their normal functions and disturbances in their division and nutritional functions which cause them to die. The rate of reduction the tumour is close to its growth rate. In AVM, a congenital vessel cluster abnormality, the Gamma Knife works by causing a thickening in the vascular walls and their progressive obstruction. Reduction of the tumour and the closing off of the AVM cluster occurs over time. This takes between 18 months to 2 years in benign tumours and AVMs, whereas due to their fast growth rate, malignant tumours and metastase may respond to Gamma Knife within a couple of months.

The Advantages of Gamma Knife treatment
The elimination of the need for open surgery in many brain tumours
Very few post-operative side effects
No need for general anaesthesia
Patient can go home the same day
No recuperation period
No scar on hairy skin and head
No shaving of hair or hair loss
High benefit with very little discomfort
Fast return to work
It is cheaper compared with some surgical interventions
Healthy brain tissue gets exposed to very low doses of radiation

The Stages of Gamma Knife Treatment

The Stereotactical frame:
At the outset of the treatment, the patient has to be fitted with a Leksell stereotactical frame around the head. This procedure is carried out under local anaesthesia. Patients under 10 years old are sedated.

Neuroradiological imaging:
Once the frame is fitted, the imaging method used is the one that is best suited for the particular pathology of the patient. These days, an MRI is performed on all patients. Angiography in AVM cases is performed with the stereotactical frame. For those patients with skull-based tumours or those who are unable to undergo MRI, a computer-aided-tomography is used in the planning of treatment.

Dose planning:
Special computerized planning programmes allow for increased accurancy, limitation of the tissue to be treated and the determination of the radiation dose to be applied. Blockage application in tumours neighbouring sensitive structures prevents the exposure of healthy tissues to radiation. The improvement of computer programmes which assist in treatment planning yields significant benefits in this regard.The patient may spend his time talking or watching television in his bed during these procedures.

Radiation application:
After a treatment plan is devised on the computer, it is applied in the treatment unit which is in a different area. This takes some time between 30 minutes to 1-2 hours. The determining factor is the size of the tumour and the amount of radiation dose that is applied.

Frequently Asked Questions

What is the Gamma Knife?
The Gamma Knife is not really a knife. Rather, it is a treatment method which uses a very sophisticated technology whereby gamma radiation is directed to the target area inside the skull in a very sensitive manner and in one single session. Just like the knife used in surgical procedures, gamma radiation destroys the diseased area in a safe and effective manner. However, there are no surgery-related problems in this case such as bleeding, infection or hospitalisation in the intensive care unit. The advanced imaging and planning techniques of Gamma Knife radiosurgery allow for the penetration of very fine gamma radiation beams which can be directed into the smallest parts inside the skull. Radiation clusters from 201 gamma radiation sources focus on the diseased area. As such, while the healthy brain tissue surrounding the diseased area gets exposed to negligible levels of radiation, while the diseased area gets impacted by a high dose of radiation. All of these procedures are completed within several hours and the patient can go home on the same day.

Can it also be applied on elderly patients with systemic diseases?
Gamma Knife radiosurgery is particularly recommended for patients who are inflicted with such problems and whose advanced age may increase the risk of serious surgery-related side effects. Gamma Knife treatment is an advantage for patients who would not do well under general anaesthesia.

What will I feel during Gamma Knife treatment?
The patient may feel the slightest pain while being fitted with the stereotactical frame around the head. Local anaesthetics are used to minimize discomfort and the feeling of pressure from the frame will dissappear in a few moments. The patient does not feel any pain during treatment. There is no question of the patient seeing or feeling the radiation either.

Is the patient awake during treatment?
Yes, the patient is awake. However, sedatives may be used to calm excited patients.
Throughout the treatment, the doctor will be able to talk with the patient through the loud speaker and microphone.He will also be constantly following the patient from the monitor.

Is the hair shaved off?
No, this method does not require the hair to be shaved off.

Is the Gamma Knife treatment safe?
Gamma Knife is a brain surgery method which ensures sensitive delivery of gamma radiation to the diseased tissue, while eliminating the need to open up the skull. Open surgery associated complications such as bleeding and infection are not encountered. Because of no hospitalization is required, there is no risk of any hospitalization-related issues. The likelihood of any radiation energy-associated reaction in the surrounding healthy tissue is 1-2%, and most of these are temporary.

How long will it take for the treatment to take effect?
It takes anywhere from several months to several years for the impact of Gamma Knife radiosurgery to be observed.Every disease is different. Patients should be under the supervision of a physician and have their MRIs and Angiographies performed at recommended intervals. The aim of Gamma Knife surgery is to contain the growth of the tumour, which may be the reduction of the size of the tumour or the interruption of its further growth.

How soon can I go back to my daily routine?
You can go back to your regular routine immediately after the treatment. Any restraints present prior to treatment are still applicable. Gamma Knife treatment does not require any special restraints.

Diseases Treatable with the Gamma Knife

ARTERIOVENOUS MALFORMATIONS
Arteriovenous malformations (AVM) are abnormal congenital vessel clusters in the brain. AVMs may manifest themselves as brain haemorrhages or epilepsy seizures.
A brain haemorrhage is likely to cause serious health problems. Furthermore, the seizures lower the quality of life of the patient.
AVMs may be treated by surgical removal, by blocking through what is called the embolisation method, or by destruction through radiosurgery. Sometimes these methods are used to complement one another.
The likelihood of AVMs disappearing within 2 years following
Gamma Knife application is around 92%.

METASTASIS
Brain metastasis occurs when cancer in a part of the body spreads over into the brain through the vessels. In this day and age, the number of cancer patients is on the rise. The success of primary cancer treatment methods has been increasing the survival of cancer patients, however, in association with this, there is an increase in the number of patients developing brain metastasis.
Approximately 20-40% of cancer patients develop brain metastasis.

Lung Cancer
Breast Cancer
Kidney Tumours etc.

Surgery, radiotherapy and radiosurgery are used to treat these diseases. Standard treatment is radiation of the entire brain and use of steroids. However, in single or limited number of small-scale metastasis, radiosurgery is recommended by itself or as complementary treatment. Because the general systemic condition is disturbed in the majority of cancer patients, surgical treatment may be problematic. Therefore, the single session Gamma Knife treatment is very advantageous in the treatment of metastasis. Gamma Knife may attain a success rate of 90% in the interruption or reduction of these tumours.
In recent years, the largest patient groups in the majority of Gamma Knife centers have been metastasis patients.
Pre treatment and fourth month post treatment MRI images of a lung cancer patient with brain metastasis

VESTIBULAR SCHWANNOMA
Vestibular schwannoma tumour involves the audiovestibular nerve. Its manifestations are ringing in the ears, progressive hearing loss and loss of balance. Treatment may be surgical, however, this may cause post-operative problems such as increase in loss of hearing or facial paralysis. Compared with surgery, the likelihood of encountering these problems is much lower in Gamma Knife treatment. Gamma Knife treatment allows for a success rate of 98% in interrupting the further growth of the tumour or ensuring its reduction in the long term.
Pre treatment, 1st and 3rd year post treatment MRI images of a Vestibular schwannoma patient

PITUITARY ADENOMA (Pituitary Gland Tumour)
Pituitary adenomas are the most frequently encountered tumours of the pituitary gland, the hormonal center of our body. These tumours manifest themselves through hormonal imbalance or loss of sight.
They may be treated with medication, surgical methods and theGamma Knife. Gamma Knife radiosurgery may be applied in addition to medication treatment surgery, or by itself.
Gamma Knife radiosurgery allows for a growth control rate of around 90% in pituitary tumours.

MENINGIOMAS
Slow growing and mostly benign, meningiomas are tumours which stem from the membranes enveloping the brain. They manifest themselves and get diagnosed through the formation of masses. First treatment of choice is surgical intervention. However, sometimes it may not be possible to fully remove meningiomas. Sometimes, a surgical intervention may carry high risk. In such cases, Gamma Knife radiosurgery represents as a convenient option. It may also be used on patients who have post-surgical remnants.
Gamma Knife has 95% success rate in the interruption of tumour growth in meningiomas and in the reduction of tumour size over time.
Pre treatment and 3rd year post treatment images of a previously operated patient with remnant Meningioma

MOVEMENT DISORDERS
Parkinson’s disease may be related to multiple sclerosis, traumas or essential tremor (observed in elderly patients, reasons unknown). It is a disease which has a negative impact on quality of life of the patient. In addition to medication, Gamma Knife thalamotomy may be used for treatment.
4th month post treatment MRI image of a patient with Parkinson disease-linked tremour

TRIGEMINAL NEURALGIA
Trigeminal neuralgia is a type of one-sided facial pain which feels like an electric shock. Pain is experienced around the sides of the nose the mouth and in the chin. Physical examination does not reveal much, it is mostly diagnosed through what is reported by the patient.Medication is the first treatment of choice. If this fails to improve the patient’s condition, various surgical interventions may be available.
Gamma Knife treatment is present among such surgical intervention options.
Rate of pain alleviation is the same as other percutaneous methods.It is a a better option in the case of elderly patients.
Treatment plan for a patient treated for Trigeminal neuralgia

EPILEPSY
Epilepsy is a disease which manifests itself through epileptic seizures observed at a rate of approximately 1% in society.
Many patients benefit from medication treatment.However, one group of patients require surgical intervention.
Gamma Knife radiosurgery may be the solution for a certain part of this group of patients.
Treatment plan for an epilepsy patient.

The Number of Patients throughout the World Treated with the Gamma Knife

How to Choose the Gamma Knife

Center that is right for you?

Choose an experienced team with a good track record of successfully treated patients. A team that has applied the Gamma Knife to a high number of patients with a variety of diseases will be in full knowledge of your needs and will deliver the required treatment protocol in the safest possible manner.
With approximately 3,000 successfully treated patients, Acibadem Gamma Knife team is in a position to boast about significant experience not only in our country, but in the world as well.
Choose a team which carries out research and publishes scientific articles on the Gamma Knife. A team with a good body of research and publications will be keeping abreast of all the developments in this field. It is advantageous for patients to receive treatment from a group that is in possession of all the recent medical advancements.
Always in full possession of latest clinical know-how, Acibadem Gamma Knife team has published many scientific articles nationally and internationally and has delivered many congress presentations in this field both in Turkey and abroad.
Choose a center equipped with the latest technology and hardware. An excellent Gamma Knife center uses the latest computer software and the latest equipment. The leading Gamma Knife centers operate an MR device with high magnetic field and a digital angiography. All of these ensure a highly effective and safe treatment for the patient.
In Acibadem Gamma Knife unit “Model 4C” is being used, the state of the art model which is the only one of its kind in Turkey. Again, we are the only center in Turkey to use the 3 Tesla MR in the planning of treatments. The use of 3T MR is being developed in the world very recently.