Gamma Knife Stereotactic Radiosurgery

Patient with head frame applied. Physicians setting up treatment machine.
Patient with head frame applied. Physicians setting up treatment machine.

The Yale New Haven Gamma Knife is the only radiosurgery unit in Connecticut dedicated to the treatment of head and neck conditions. 

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Staffed by a team of specialists with cumulatively greater than 30 years of radiosurgery experience, treatment at our center results in predictable and nationally recognized outcomes. While the majority of our patients are adults, the Yale facility has also treated many pediatric patients.

The Principle

Stereotactic radiosurgery is the delivery of a high dose of highly focused radiation in a single session to treat specifically chosen intracranial targets. At Yale, this treatment is delivered using a unit called the Gamma Knife -Originally designed by Dr Lars Leksell in Sweden, this machine contains 192 cobalt-60 sources arranged in a hemispherical array and housed in a heavily shielded unit. Using this unit, radiation is precisely focused to deliver the high dose of radiation only to the designated target while sparing the surrounding tissues. Complex shaped lesions can be treated by combining varying-sized collimators with selected beam blocking and dose weighting using very sophisticated computer planning software. This ensures that each patient's lesion(s) receive a tightly conformal "tailored" treatment plan.

Experience and Safety

The Yale New Haven Hospital Gamma Knife Center is the radiosurgery center with by far the most treating experience in Connecticut. The Gamma Knife remains the gold standard machine for radiosurgical treatment of brain lesions because unlike linear accelerator (LINAC) based systems, including the Cyberknife, the Gamma Knife has few moving parts thereby eliminating many sources of inaccuracy and unreliability. The Gamma Knife is a machine dedicated to treating the head and is only available in Connecticut here at the Yale New Haven Hospital. Almost 3000 patients have been treated at the center since 1998 for a variety of conditions.


The most common indications for use of Gamma Knife include:

  1. Brain Metastases – most commonly from lung cancer, melanoma, breast cancer, colon cancer, renal cell cancer and gynecological and genito-urinary cancers,
  2. Benign Brain Tumors – such as meningiomas, vestibular schwannomas, and pituitary adenomas,
  3. Arteriovenous Malformations, and
  4. Trigeminal Neuralgia 

The Center also has experience treating other conditions such as:

  1. Intraocular Melanoma
  2. Head and Neck cancers such as nasopharyngeal carcinoma
  3. Recurrent Malignant primary Brain Tumors
  4. Glomus Jugulare tumors
  5. Essential Tremor (GK thalamotomy)

Many of the conditions that are treatable by radiosurgery are also treated by surgery. Gamma Knife gives the neurosurgeon the ability to effectively treat these conditions with similar surgical precision without many of the risks and discomfort of open surgery and general anesthesia. Gamma Knife radiosurgery requires no incisions, is performed under local anesthesia and is performed with minimal discomfort. Radiosurgery has therefore been particularly useful in patients with co-existent illnesses where conventional surgery would pose an unacceptable risk. Finally, as a one-day outpatient procedure, the cost effectiveness of Gamma Knife treatment often exceeds that of open surgery. Hospitalization is only required in exceptional circumstances and most patients are able to return to their normal activities within 24 hours of the procedure.

Candidates for Gamma Knife are selected for treatment only after a thorough review of all prior medical records and imaging studies by our specialist teams of neurosurgeons and radiation oncologists.

Gamma Knife Surgeons