What is radiosurgery with the PERFEXION Gamma Knife?
Gamma Knife surgery is a modern method of radiosurgery that has been used for many years to treat brain diseases. The state-of-the-art Gamma Knife PERFEXION has now been installed in the Radiation Oncology Unit at Gayrettepe Florence Nightingale Hospital and our competent team is successfully applying the Gamma Knife treatment. This model has been upgraded with more capabilities than a simple new or refurbished model. With the PERFEXION, more efficient treatment and fewer side effects are achieved.
How does the PERFEXION Gamma Knife work?
In radiosurgery with the PERFEXION Gamma Knife, 201 high-energy beams from the cobalt source are focused and sent to the designated target within defined limits with high sensitivity. The shape and dose of the beams can be optimized to affect only the target without causing any damage to healthy tissue, as there are millions of different types of possible beam configurations. With treatment, the DNA of the tumour or lesion cells is degraded and the cells lose their ability to survive. This causes the tumour to shrink in time.
Vascular Diseases
Vascular diseases - the application of the same causes thickening of the vein wall and gradual closure of the vascular malformations. In malignant tumours and metastases, only a few months are enough to achieve a good result. Functional diseases, since the aim is to make a small size lesion at the target site in the brain, a higher dose of beam is sent to the target cells. The lesion that is created by this application stops the abnormal sending of signals and treats functional diseases and symptoms, such as movement disorders, pain or epilepsy.
What are the phases for treatment with the PERFEXION Gamma Knife?
Patient selection and preparation for surgery: the decision for radiosurgery is made after all information concerning the patient is evaluated and a consensus is reached by a board that consists of a brain surgeon, a radiation oncologist and other specialists. Since this method does not require an incision, hair cutting or general anaesthesia and is a minimally invasive method, they are informed that the procedure will be completed in one day and the patient will be home that evening.
Framing
Framing: This is a step that requires setting a goal to be influenced with a high degree of precision. The frame is stabilized tightly on the skull using screws from four different points, allowing for a true stereotactic radiosurgical treatment unlike other radiotherapy methods. The goal is achieved using high sensitivity, averaging 0.15 mm. The frame is placed on stabilized points under light anaesthesia and local anaesthesia is applied to the stabilizing points on the patient's head. The only disadvantage of this procedure is that it could not be applied to children under 8 years of age.
Targeting and Dose Planning
Targeting and dose planning: After radiological imaging, the patient is guided to the room and has the chance to rest, eat, drink, etc., during the 1-2-hour dose planning period. The radiology images that are used in the stereotactic volume are included in the treatment planning program. The target and its boundaries are identified and marked as dose planning is done and the dose to be sent is determined.
Radiosurgical Treatment
Radiosurgical treatment: once the planning phase is completed, the patient is brought to the Treatment Unit. The treatment time varies from a few minutes to several hours depending on the number and size of the lesions. The Treatment Sector is a bright and spacious area. The irradiation sector is also extremely wide, so there is no problem for patients who suffer from claustrophobia. The patient is monitored using a monitor and can be spoken to during the treatment period. In case of a problem, the treatment can be interrupted and then continued from the same place.
Postoperative Period
Post-operative period: after treatment, the frame is removed from the patient's skull. A report is provided to the patient or their relatives which includes details of the therapy and planning phase. The patient is taken to the room to rest for a few hours and then discharged.
Follow-up: the patient is monitored at intervals depending on the lesions treated and periodic follow-up radiological images are taken.
Gamma Knife Worldwide
Currently, Gamma Knife is used in 275 centres worldwide. A total of 676.000 patients have been treated with the Gamma Knife and the figure is gradually increasing to 65.000 per year.
The experience and information that comes from the increase in the number of diseases and patients cured is shared between the Gamma Knife Centres through a dedicated website. This experience is shared with the whole world with the help of 3000 scientific publications.
The Gamma Knife in our hospital is the first of the PERFEXION type in our country and in neighbouring countries. Therefore, our patients are not only
Turkish citizens. At least a total of 30% of our patients are foreign patients from other countries.
Conditions that are Treated with Gamma Knife
Acoustic Neuroma
Acoustic neurinoma: As it is located near the brain stem, cranial nerves, auditory system, cerebellum and underlying vascular structures, operating on these types of tumours is always a risky method. Facial nerve damage is a surgical complication that occurs in 40 percent of cases. By using the PERFEXION Gamma Knife radiosurgery method, the risk of facial nerve damage is reduced and the auditory system is protected at the same time. It is also used for postoperative residual tumors and cases of recurrence.
Arteriovenous Malformations
Arteriovenous malformations: these represent the main group of intracranial vascular lesions that are treated using the PERFEXION Gamma Knife. All treatment methods such as surgery, endovascular intervention and Gamma Knife are prepared and available for such conditions in our centres. However, combining these methods provides more successful results.
Pituitary adenomas: alongside primary pituitary tumours, treatment of residual tumours and recurrences could be planned in order to preserve optic nerves and normal tissues. The PERFEXION Gamma Knife is the first option of choice, especially for cases that involve the cavernous sinuses and adenomas that invade the carotid artery, which otherwise carry a very high surgical risk.
Meningiomas
Meningiomas: meningiomas are usually benign tumours that originate in the cerebral cortex and are sometimes located in high-risk sites for surgical removal. It is possible to treat these tumours with the PERFEXION Gamma Knife. In cases of large meningiomas, after maximal surgical excision, the Gamma Knife is applied to the at-risk tumours, which has been a popular method in recent years and is assumed to bring fewer complications. Moreover, it is also actively used in the treatment of recurrent meningioma cases.
Trigeminal Neuralgia
Trigeminal neuralgia: treatment of trigeminal neuralgia that causes facial pain can be performed using the PERFEXION Gamma Knife. Other treatments that target this condition (microvascular decompression, percutaneous radiofrequency ablation and compression, local injections, etc.) are also available at Florence Nightingale Hospital Group.
Vascular Diseases
- AVMs (Arteriovenous malformations)
- Aneurysm
- Cavernous angioma
- Other vascular diseases
Benign Tumours
- Acoustic neuroma
- Tumours in the area of the pineal gland
- Trigeminal neuroma
- Hemangioblastoma
- Other schwannomas
- Hemangiopericytoma
- Benign glial tumours (grade I + II)
- Craniopharyngioma
- Chordoid meningiomas
- Pituitary adenoma (secretory)
- Glomus tumours
- Pituitary adenoma (non-secretory)
- Other benign tumours
Malignant Tumours and Metastatic Brain Tumours
- Malignant glial tumours (grade I + II)
- Metastatic tumours
- Chondrosarcoma
- Carcinoma without previous history
- Other malignant tumours
- Ocular diseases
- Uveal melanoma
- Functional diseases
- Glaucoma
- Trigeminal neuralgia
- Hemangioblastoma
- Parkinson's disease
- Hemangiopericytoma
- Persistent pain
- Craniopharyngioma
- Epilepsy
- Chordoma
- Obsessive-compulsive disorder (OCD)
- Glomus tumours
- Other functional diseases
- Other eye tumours
Gamma Knife Vs Open Surgery
- The advantages of the Gamma Knife:
- Performed in one session in one day.
- Can be performed in cases where surgery is not an option.
- Highly sensitive targeting method.
- Minimal risk compared to normal surgery.
- Easy treatment without pain.
- Patient can immediately return to daily activities
- The procedure could be repeated if necessary.
Undoubtedly, open surgery cannot be replaced by Gamma Knife surgery and this is not its purpose; on the contrary, these are two surgical methods that complement each other. Some of the lesions are more suitable for Gamma Knife surgery, while others are more suitable for open surgery. In some cases, it may be necessary to apply both. For example, in some larger tumours, a two-phase procedure may be planned to reduce the volume of the lesion, and sites that cannot be reached or removed due to their location may be treated with Gamma Knife surgery. In cases where Gamma Knife surgery can be applied, it is preferable to open surgery in terms of patient comfort and treatment costs. Certainly, patients will prefer the bloodless, painless method without anaesthesia.