Gamma Knife Radiosurgery

Gamma Knife surgery is a type of noninvasive procedure used to shrink or kill the tumor with the help of ionizing radiation. Unlike conventional surgery, Gamma Knife surgery does not include the use of scissors or surgical blades and knives to make an incision to access the tumor.

Gamma Knife is actually the name of the technique and the equipment that is used to deliver precise radiation to the tumor site. It allows for precise targeting of the tumor without affecting the nearby healthy cells and tissues.

It is a type of stereotactic radiosurgery (SRS) and similar to other techniques such as CyberKnife and X-Knife. Each type of SRS has its own benefits and limitations and therefore, the treatment is applied after careful selection of the candidates for each of these techniques available.

Gamma Knife radiosurgery uses specialized computerized treatment planning software that helps physicians locate the small target areas inside the head. These target areas are then irradiated with extremely high precision without damaging the nearby tissues.

This type of radiosurgery is now used for the treatment of a number of conditions, including primary or metastatic brain cancers, benign brain tumors (meningioma, acoustic neuroma, and pituitary adenomas), vessel malformations such as arteriovenous malformations, and functional disorders such as trigeminal malformations.

What is it used for?

Gamma Knife radiation is used to treat brain lesions and inoperable tumors in the brains by targeting them with enough radiation. After the procedure, the targeted lesion is expected to shrink, disintegrate completely, or stop growing any further.

This type of radiosurgery is now used for the treatment of a number of conditions, including primary or metastatic brain cancers, benign brain tumors (meningioma, acoustic neuroma, and pituitary adenomas), vessel malformations such as arteriovenous malformations, and functional disorders such as trigeminal malformations.

How is it performed?

Gamma Knife radiosurgery uses multiple beams of radiation to converge in three dimensions to focus on a small area of tumor or lesion precisely. This permits a large volume of high-dose radiation to be delivered with accuracy.

The Gamma Knife machine commonly being used worldwide uses robotic technology for submillimeter patient movement during the procedure to ensure that the complete targeted location is irradiated.

The following are the major steps that are executed during the procedure:

• An IV line is attached to the arm to deliver a contrast solution. The solution also has a little sedative added to help you relax during the procedure.
• A headframe as prepared after taking the measurement is attached to position the target and also prevent movement during the procedure.
• A local anesthetic is given at the location where the head frame pins are inserted. The technician takes a measurement of the head to plan the delivery of radiation.
• CT/MRI is taken to confirm the exact location of the lesion.
• The radiation oncology team then sets the machine and configures the area to be targeted, the dosage, and how to target it. All of the readings are set on the computer that controls the radiation.
• You are made to lie on the Gamma Knife couch and the head frame is attached to the bracket in the machine.
• A microphone is attached near your head so that you are able to communicate with the team outside.
• The couch moves inside the machine and the radiation is delivered to the targeted location. The session may take anywhere from 30 minutes to 3 hours, depending on the location and size of the target.
• Once radiation is delivered, the couch moves out and the team comes and removes the head frame. An ointment is put on the site of the insertion of head frame pins.

Depending on the requirement and treatment planning, a patient may need 1 to 5 sessions or sittings of Gamma Knife radiation to treat the lesion.