Stereotactic Radio Surgery (SRS) is a high precision radiotherapy technique that delivers significantly high doses of radiation to an accurately localized target inside the body. SRS is typically performed in a single session, using
a rigidly attached stereotactic guiding device, other immobilization technology, and/or a stereotactic image-guidance system, but can be performed in a limited number of sessions, up to a maximum of five. Stereotactic Radiotherapy has various radiation delivery methods, such as Gamma-Knife, X-Knife, and Cyber-Knife for patients who are searching for an alternative to surgery for a tumor in the brain, lungs, liver, spine, etc. SRS uses a high-quality 3D image to target a high dose for the treatment with minimal impact on surrounding healthy tissues.
Gamma-Knife Vs X-Knife/Cyber-Knife:
Gamma-Knife and X-Knife both are SRS treatment technologies but with different radiation delivery methods – the former uses Gamma rays while the latter makes use of X-rays. The major objective of Gamma-Knife and Cyber-Knife is to destroy the tumor and the result is as same as the surgery but without having it. Some of their significant differences are:
- Gamma-Knife needs a large size metal frame, which is mounted with screws onto the patient’s head, before and during the treatment. But X-Knife is a non-invasive and pain-free treatment. The patient lies down on the bed comfortably during the treatment.
- The patient does not need local anesthesia during the procedure in X-Knife, unlike Gamma-Knife.
- X-Knife is able to treat the tumors anywhere in the body in 1-5 radiation sessions. Whereas, Gamma-Knife can cure only brain or cervical spine cancer with a high dose single session of treatment.
- The Gamma-Knife treatment came in practice in the 1950s while X-Knife practice was started in the 2000s.
SRS can be used to treat different neurological problems and other conditions like:
- Brain Tumor: SRS is majorly used in brain tumors both malignant (brain metastases) as well as benign (meningioma). Other methods can be used if cancer gets spread from the brain to other parts of the body (brain metastases).
- Arteriovenous malformation (AVM): AVM is a disruption in the brain’s arteries and veins which interrupts the normal flow of blood and leads to bleeding (hemorrhage) or stroke.
- Trigeminal Neuralgia: It is a chronic pain disorder, which stops the relay of sensory information between the brain and facial parts. It creates pain which feels like an electric shock.
- Acoustic Neuroma: It is a non-cancerous tumor, which usually develops in hearing nerve leading from the inner ear to the brain. A person with acoustic neuroma usually suffers from hearing loss, dizziness, loss of balance, pain in facial muscle movement, and ringing in the ear.
- Pituitary Tumors: The pituitary gland is responsible for the hormonal control and controls various functions such as stress, metabolism, and sexual function.
- Other Cancers involving Liver, lungs, and spine.
- Other diseases: Parkinsonism.
Dr. Sayan Das, Associate Consultant – Oncology, Radiation Oncology, Narayana Superspeciality Hospital, Howrah