Gamma Knife®

Gamma Knife® surgery uses radiation to treat tumors and lesions in the brain. It is not a knife in the normal sense of the word, and the surgeon makes no incisions.

The surgery focuses extremely precise gamma radiation beams on a specific area within the brain while the patient's head is enclosed in a helmet-like device (collimator) which holds the patient still and allows the beams to enter through small openings.

During treatment all of the radiation beams meet at a focal point. The individual beams are too weak to damage healthy tissue on their way to the target area, but very powerful when they simultaneously merge at a single focal point. This can be compared with the principle of a magnifying glass in the sun.

By placing the head in one or several positions, the shape and dose of radiation is optimized to affect only the target - without damaging surrounding healthy tissue. The effects of the surgery will occur over time as radiation treatments are designed to stop the growth of tumors or lesions.

Gamma Knife® surgery does not require patients to cut or shave their hair. During treatment patients are fully awake and able to communicate with their doctor and nurse. Some patients may experience a mild headache or swelling where the collimator was attached, but most report no problems. Otherwise, the procedure is painless and allows patients to return quickly to their normal routines.

CJW Medical Center is one of only two hospitals in the state currently performing Gamma Knife® surgery.

Gamma Knife Physician Leaders
at CJW Medical Center

K. Singh Sahni, M.D.
Dr. Sahni is board certified by the American Board of Neurological Surgery and is an American College of Surgeons Fellow. He has been published in numerous medical journals and has spoken internationally on neuroscience subjects.

Dr. Sahni completed his residency in neurosurgery at the Medical College of Virginia in 1983. He served as assistant professor of neurosurgery and director of stereotactic and functional surgery at MCV until 1988. He joined CJW in 1989, where he has served as chief of neurosurgery.

Dr. Sahni has performed more than 1,000 surgeries on patients with trigeminal neuralgia in the last 20 years. His other areas of interest include trigeminal neuralgia, hemifacial spasm, pituitary tumors and acoustic tumors.

Professional Societies:

  • American Medical Association
  • American Association of Neurological Surgeons
  • American College of Surgeons
  • Congress of Neurological Surgeons (International Committee)
  • American Academy of Pain Medicine (Founding Member)
  • American Society for Stereotactic & Functional Neurosurgery
  • Medical Society of Virginia
  • Richmond Academy of Medicine