Are There Any Side Effects of Gamma Knife Radiosurgery?

Gamma Knife Radiosurgery

Gamma Knife radiosurgery is a boon to those who cannot withstand traditional surgery in which they’d have to undergo anesthesia, or in cases where surgery isn’t an option due to the location of the tumor. Nonetheless, if you’re considering undergoing this procedure, you’re probably curious about the immediate and delayed side effects of Gamma Knife radiosurgery.

How Gamma Knife Radiosurgery Works

To have a clearer picture of possible side effects that may come with Gamma Knife radiosurgery, it’s important to understand the way the procedure works. Despite the words “knife” and “surgery”, this procedure doesn’t involve either. Instead, Gamma Knife radiosurgery depends on the use of around 200 tiny beams of radiation that are all focused on the area in need of treatment. While each beam on its own is not particularly potent, when it converges with the other beams, it delivers what is called a “therapeutic dose” of radiation. This means that the radiation created at the target is high enough to effectively damage and destroy the offending cells.

Side Effects of Gamma Knife Radiosurgery

While the potential side effects often associated with traditional surgery are avoided, such as infection, incision/surgical site pain, swelling, etc., Gamma Knife radiosurgery can have some potential side effects. Some of these appear shortly after the procedure, while others may take longer to spring up. Luckily, any side effects of Gamma Knife radiosurgery tend to be mild in comparison to those of their surgical counterparts.

Why Your Medication Is Not Working

There are a few different types of medications used to treat trigeminal neuralgia. Some help ease the pain directly, while others try to provide relief by eliminating the cause of the dysfunction. Sometimes the nerve is overstimulated, and medications can help inhibit it from firing excessively and causing pain. Anti-seizure medications and some antidepressants can help in this fashion and are typically the first step your doctor takes in treating your trigeminal neuralgia.

However, sometimes your trigeminal neuralgia medication does not work. This may happen because your condition is a result of something physically pressing on the nerve and causing it to fire inappropriately. Sometimes a tumor is causing the pressure, but it is most commonly a blood vessel near the brain that is the culprit. When this is the case, further intervention to remove the impingement may be necessary in order to provide relief.

Your Next Steps

If you feel like your trigeminal neuralgia medication is not working, it is important you schedule an appointment with your doctor immediately. Your doctor will discuss your symptoms and whether you have received any relief from your medications, which ones and to what degree. Sometimes imaging may be necessary to help your doctor determine the next appropriate steps. It is important you are working with someone experienced in treating your condition, such as a neurologist, as you move into your next phase of treatment.

Immediate Side Effects

Most immediate side effects are mild and resolve within a few days after you’ve undergone Gamma Knife treatment. The more common side effects include:

Swelling and Soreness of the Scalp

This is due to the irritation at the points on the scalp where the headframe was secured. In most instances, this will heal up and go away within a few days. If you have sensitive or easily irritated skin, let your surgeon and his or her team know so that they can take measures to minimize potential swelling and discomfort.


Many people report having mild-to-moderate headaches following their Gamma Knife radiosurgery treatment. This usually goes away within 24 to 48 hours.

There are a few rare side effects that can happen immediately or within a couple of days of undergoing a gamma knife treatment. These include:

Reddening and Irritation of Skin Within the Treatment Areas

This is not a particularly common side effect but has been reported. If you experience reddening and/or irritation, call your surgeon’s office to find out what the best course of action is.


While rare, nausea can occur post-procedure. Talk to your doctor ahead of time about ways to address severe nausea that may arise from your Gamma Knife radiosurgery.


Seizures in Gamma Knife patients are very rare, but they can sometimes occur. If you have epilepsy, have ever had a seizure or are worried about this potential side effect, make sure your surgeon is aware of your concerns and takes the necessary precautions if you are predisposed to seizures.

Delayed Side Effects

The delayed side effects of Gamma Knife are a less common occurrence, but some patients do still experience the following complications. They can include:

Hair Loss

Hair loss can occur as a temporary side effect in localized and superficial lesions. Some patients report experiencing scalp soreness prior to their hair coming out. In the vast majority of cases, the hair will grow back fairly quickly.

Localized Brain Swelling

Temporary localized brain swelling can occur at the treatment site, but it is quite uncommon. If you suspect you are experiencing brain swelling, consult a doctor right away.

Numbness in the Face

In some instances, people that have undergone Gamma Knife radiosurgery for conditions such as trigeminal neuralgia may experience some numbness in their face, directly related to the part of the nerve that was treated. In some cases, this numbness will resolve, while in others it can be permanent.

Final Thoughts

Although the above side effects sound intimidating, most of them happen in only a small percentage of patients. The benefits of Gamma Knife radiosurgery far outweigh the risks if you cannot undergo traditional surgery for one reason or another. Be sure to talk to your surgeon prior to your procedure to ensure you fully understand both the risks and benefits of this lifesaving treatment.

Get Your Questions Answered, By a Real Person.

Our Patient Liaison is here to help you understand your next step. After discussing your specific case, she can help you navigate your medical records, answer insurance questions, and connect you with one of our nurses, at no charge to you.

While we are taking all necessary precautions in response to COVID-19, the Valley Gamma Knife team is still available to help new and existing patients, including via virtual consultations. To discuss your specific case with our Nurse Navigator, call 201-571-6494.