Gamma Knife radiosurgery is a technique that uses intracranial stereotactic radiosurgery. It may be helpful in treating deep lesions that can not be reached through traditional surgery.

What is the Gamma Knife radiosurgery?

Gamma Knife radiosurgery is a technique for intracranial stereotactic radiosurgery. The machinery allows high doses of radiation to be administered with extreme precision on a target within the skull, such as a nerve, a ganglion or an area of the brain, while preserving the surrounding structures. The technology allows the focus to be on a single target within the brain with a beam of 201 gamma rays.The radioactive source used is cobalt.

The treatment involves four steps :

  • Application of stereotactic system (to pinpoint the area to be irradiated).
  • Brain mapping using imaging techniques such as MRI, CT and cerebral angiography (to determine the shape, size and position of the area).
  • Treatment plan (which specialists will customize according to the individual characteristics and needs of the patient).
  • Treatment: the patient will be relaxed with a helmet attached to the Gamma Knife stereotactic system and will remain awake during the entire session, the duration of which can vary depending on the target.

How is Gamma Knife radiosurgery performed?

The patient is lightly sedated and then the stereotactic frame is placed to subject the patient to imaging tests. The images will allow the specialist to plan for the most proper form of treatment. Once decided upon, the patient will lay with a stereotactic frame fixed onto the Gamma Knife bed. The treatment can last from one to six hours, depending on the needs of the patient and the target area for radiation.

What are the advantages to undergoing Gamma Knife radiosurgery?

Gamma Knife radiosurgery is a minimally invasive procedure , done in a single session and free of pain and surgical incisions. The procedure is almost always done on an outpatient basis and the patient is usually discharged the very same day.  

Is Gamma Knife radiosurgery painful or dangerous?

The procedure is not painful, though the patient may feel pain during positioning of the four small metal pins to stabilize the helmet. During the actual treatment, the patient will undergo subtle movements of the head, though they will not experience any pain or noises.

For which diseases is Gamma Knife radiosurgery used for?

Patients with brain metastases, meningiomas, pituitary adenomas, arteriovenous malformations (AVM), acoustic neuromas, trigeminal neuralgia, uveal melanomas, cavernous angioma and movement disorders can all undergo this type of treatment.

  • Gamma Knife for brain metastases
  • Gamma Knife for meningiomas
  • Gamma Knife for pituitary adenomas
  • Gamma Knife for arteriovenous malformations
  • Gamma Knife for acoustic neuromas
  • Gamma Knife for trigeminal neuralgia and other facial pain
  • Gamma Knife for uveal melanomas
  • Gamma Knife for cavernous angioma
  • Gamma Knife for movement disorders

Follow up

The results of the procedure are not immediate. The patient will be informed of any additional examinations that need to be carried out during discharge.  The radiation effect can take effect after months and / or years. Sometimes, Gamma Knife treatment may not be enough and further treatment may be necessary, both of Gamma Knife combined with other techniques. 

What steps should be taken to help prepare for this procedure?

A few days before undergoing the procedure, the patient will travel to Humanitas for pre-admission and will be subjected to a blood test, an electrocardiogram (ECG), an eye examination or hearing test, and a medical examination for a complete compilation of medical records. It is important that the patient announce any allergies to medications or contrast agents, or claustrophobia. On the day of the procedure, the patient should be accompanied by a family member or an acquaintance and should have been fasting from midnight the night before. On the night before the procedure, the patient should cleanse themselves with a product-based disinfectant shampoo, such as chlorhexidine. It is best to avoid wearing any jewelry: brooches, hairpins, makeup, hair products, and artificial nails; but rather wear comfortable clothing and footwear, preferably with buttons or zippers.