PBS Logo
(609) 921-9001 NJ
(215) 741-3141 PA
New Jersey (609) 921-9001
Pennsylvania (215) 741-3141

About PBS

Chiari Malformation Pages
Patient Testimonials
Pre-op and Post-op Guides Preparation and Recovery


WBCB Radio


Our neurosurgical team now serves Lower Bucks Hospital in Bristol, PA. See all locations here.


Appointment Info
Phone, Forms, Directions

Register Online

Our Philosophy Video


Dr. Joseffer explains recent brain tumor diagnosis of Sen. John McCain


Doctor Testimonials

What Do Doctors Think About Before Cervical Spine Surgery? Watch Video Now


Gamma Knife: Radiosurgery

What is the Gamma Knife?
Despite its name, the Gamma Knife is not a blade, knife, or scalpel. It is a remarkable piece of equipment that precisely and safely aims a high dose of radiation at brain tumors or malformations (lesions). The Gamma Knife offers patients an alternative to traditional open-skull brain surgery or microsurgery that minimizes patient risk and physical trauma while accurately treating malformed brain tissue.

The technology behind the Gamma Knife is a blend of engineering and physics. The Gamma Knife directs photon radiation from up to 201 sources to a single target. The beams of radiation are coordinated to intersect into one intense beam that focuses on the target tissue. The target can be quite small, from several millimeters to three centimeters in diameter. The effects to tissues surrounding the tumor or malformation are minimal.

The Gamma Knife is also called stereotactic radiosurgery or radiosurgery , because it uses a stereotactic frame (technology that allows the surgeon to position the patient’s head very precisely) and radiation. The rigid stereotactic frame is fixed to the patient’s skull to immobilize the head and is used to precisely locate the brain tumor or malformation. Patients experience little discomfort and the treatment session may last from 10 to 40 minutes. Every aspect of the procedure is customized to meet the patient’s needs.

Components of the Gamma Knife
Although not all Gamma Knife systems look the same, structurally they are similar and consist of six components:

  • Radiation unit
  • Collimator helmets (see below)
  • Patient table or couch
  • Hydraulic system to move the table in and out of the unit
  • Operator control console
  • Three-dimensional computer-aided system to plan and administer the treatment

A collimator helmet is a helmet-like device with small openings or portals of different sizes. The beams of radiation are positioned to pass through the portals and intersect at a center point. The patient’s skull is positioned in the helmet and held in place using a stereotactic head frame. The aluminum frame attaches to the helmet and holds the patient’s skull perfectly still during the treatment.

The Gamma Knife unit is located in a specially designed room equipped with television monitoring and a two-way voice communication system. These systems allow the physician to see and converse with the patient during treatment.

Conditions Treated Using the Gamma Knife
Gamma Knife technology can be used to treat a variety of conditions, including:

  1. Benign (non-cancer) and malignant (cancer) tumors within the skull, such as acoustic neuromas, pituitary adenomas, pinealomas, craniopharynigiomas, meningiomas, chordomas, chondrosarcomas, and glial tumors.
  2. Abnormal vascular formations (artery, vein), which includes arteriovenous malformations or AVMs.
  3. Functional disorders that include trigeminal neuralgia, Parkinson’s disease, epilepsy, and intractable pain.

When treating a tumor or lesion, the Gamma Knife does not remove the tumor or lesion. Instead, the treatment disrupts the tumor’s DNA, which interferes with the tumor’s ability to survive.

Side Effects to the Gamma Knife
The side effects to Gamma Knife treatment may include swelling and, very rarely, necrosis (tissue death). If swelling does occur, steroid medication may be administered to reduce the amount of inflammation and fluid within the tumor or lesion cavity. Your doctor will carefully monitor for any side effects and will treat them promptly if they arise.

Advantages and Benefits
The Gamma Knife is a non-invasive and non-surgical treatment that eliminates the physical trauma and many of the risks associated with conventional open brain surgery. Complications from traditional surgery may include infection, spinal fluid leakage, bleeding, nerve dysfunction, and heart or lung problems.

  • The Gamma Knife’s accuracy helps to preserve tissues surrounding the target area.
  • For some patients, traditional open-skull or microscopic brain surgery is not an option. This may include patients who are too ill or elderly for surgery, or who are being treated for a recurrent or residual tumor.
  • Some tumors or lesions are inoperable, meaning they cannot be treated using open-skull or microscopic brain surgery. The Gamma Knife may be used to treat these disorders.
  • Complications from general anesthesia are avoided, as the patient only needs mild sedation.
  • Most patients only need to stay overnight in the hospital following treatment.
  • Rarely does nausea, vomiting, or headache occur following treatment.

If you would like more information about the Gamma Knife, or the conditions it treats, please contact Princeton Brain and Spine Care. We will be pleased to answer your questions about this safe and effective non-surgical approach to treating brain disorders.

Brain Surgery

LastUpdate: 2016-05-11 16:58:20


By using this site, you acknowledge that you have read and agreed to the terms of our User Agreement . The information provided is not intended to replace the medical advice of your doctor or health care provider.
© 2018 Princeton Brain & Spine

  • top