It is a type of stereotactic radiosurgery (SRS). But contrary to its name, it is a knifeless, non-invasive medical procedure, that uses highly focused radiation beams to well defined target areas in brain, as a treatment for brain tumors and other kinds of intracranial ailments.
The tumours which are inoperable or candidates unfit for surgery, now have a treatment option in form of Gamma knife. Gamma Knife treatment can also be used when prior surgery or radiation therapy has failed to control the disease process. It can also be used in conjunction with conventional surgery in previously inoperable cases, other forms of radiation therapy and chemotherapy.
It may be advised in patients suffering from:
- Brain metastases
- Acoustic neuroma/Vestibular schwannoma
- Meningioma
- Pituitary adenoma
- Glioma/astrocytoma
- Craniopharyngioma
- Hemangioblastoma
- Arteriovenous malformations (AVM)
- Trigeminal neuralgia
PROCEDURE
First, the head is fixed onto a rigid head frame with four small screws that ensures that radiation beams are precisely targeted and the head does not move during the procedure. Patients then undergo imaging scans (CT / MRI /angiography) in order to precisely locate the diseased area. Data from the imaging study is transferred into the treatment planning computer. After complete planning, with the patient on Gamma Knife table, head frame attached to the helmet inside the machine, the system delivers approximately 200 highly focused cobalt-60 source radiation beams into a single target area of the brain, while the nearby healthy tissue is spared. The beams are delivered all at once, multiple times and in short bursts.
DURATION
Treatment is commonly delivered in one session, which can last from 30 minutes to 3 hours.
Usually done as a day care procedure, it may require overnight stay in hospital.
RECOVERY
There can be mild headache for few hours. Normal activity can be resumed within 1-2 days. It may take few months before the actual benefit becomes visible. The outcome varies in different types of tumors.
RISKS
- Local pain
- Swelling
- Headache
- Hair loss
- Vision/Hearing loss, depending on the area being treated