Surgery without a Knife: Gamma Knife Radiosurgery

Gamma Knife Radiosurgery is a noninvasive type of radiotherapy treatment, alternatively called stereotactic radiosurgery. Although, it doesn’t actually use a knife, nor does it require incisions. So, how does it work? It uses very focused, energetic beams of gamma rays to stabilize, shrink, or destroy lesions or tumors. 

What kinds of cases are treated with Gamma Knife Radiosurgery? The most common cases include tumors (both malignant and benign) and lesions in the brain, trigeminal neuralgia (a condition when the pressure on the trigeminal nerve causes spasms of extreme facial pain), acoustic neuroma (benign tumor in the brain affecting hearing nerves), and arteriovenous malformations (AVM) (multiple expanded blood vessels that disrupt normal circulation to the brain). 

Gamma Knife treatment usually involves the following steps. Trimming of hair in the region of the head frame insertion sites, as well as sterilization of the skin on the head where the pins will be placed. Local anesthesia is injected at the head frame pin insertion sites. The head frame is then attached to the head using pins inserted into the skull. After the frame is stabilized, brain imaging occurs to find the location of the brain tumor or lesion, either through CT or MRI scans. The radiotherapy team will use the images to create a treatment plan. The patient is laid down on a sliding table in the room with Gamma Knife equipment. A collimator helmet may be fitted over the head frame, it has 201 holes in it, allowing radiation beams to pass through it into the brain in a precise pattern (determined by a computer). The table slides into the Gamma Knife unit, and the treatment team goes into another room to avoid radiation.The patient will likely be awake, but will not feel or hear anything from the unit. The treatment session may span from 2-4 hours, depending on the treatment plan. The patient will then be slid out, the head frame will be removed, and the pin insertion sites cleaned and covered with sterile dressings.

Written by Hana Shqairat at Incisionary

References

Cleveland Clinic medical professional. (2026, January 26). What is Gamma Knife Surgery?. Cleveland Clinic. https://my.clevelandclinic.org/health/procedures/16559-gamma-knife-surgery 

Gamma knife radiosurgery | Johns Hopkins Medicine. (n.d.). https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/gamma-knife-radiosurgery