CyberKnife® | Radiation Therapy | MedStar Health
A Cyberknife machine in a treatment room at MedStar Georgetown University Hospital.

State-of-the-art system for precision radiation therapy

The CyberKnife® system is a painless, non-invasive form of radiation. It offers accurate, effective treatment for tumors anywhere in the body—even in places previously considered unreachable. This form of radiation therapy uses a combination of computers, image-guided cameras, and robotic technology to aim directly at tumor cells while limiting exposure to nearby healthy tissue.

At MedStar Health, we were the first on the east coast to use this state-of-the-art technology, making us the most experienced CyberKnife program in the region. We are able to successfully treat patients who:

  • May not be eligible for surgery because of other medical conditions
  • Have a tumor that returned after radiation in the past

Advantages of CyberKnife

Fast and effective: Numerous benefits over conventional radiation

This technology offers several advantages over conventional external radiation treatments as well as other radiosurgery systems, including:

Comfort during and after treatment

  • This system was designed for patient comfort during treatment.
  • This form of radiation therapy tracks the target's position throughout treatment, eliminating the need to immobilize the area of the body being treated.
  • Most patients experience minimal or no side effects and recover quickly from radiation therapy.
  • It uses the Synchrony Respiratory Tracking System® to follow tumor movement, even while you breathe. Other techniques require patients to hold their breath during treatment.
  • It uses the body's bony structures or implanted markers to find its target. Similar techniques require patients to wear uncomfortable frames during the procedure.

Effective and precise.

  • CyberKnife provides radiation to the tumor from more than 1,400 different possible angles to:

    • Concentrate radiation on the tumor itself
    • Avoid surrounding, healthy tissue
  • It treats previously radiated areas safely and effectively.
  • It allows doses to be spread over multiple visits.

    • Unlike other radiosurgery systems
    • Particularly helpful for avoiding damage to nearby normal tissues

Faster than conventional cancer treatments.

  • CyberKnife targets tumors previously considered unreachable by surgery or radiotherapy.
  • With this treatment, you may have fewer complications and lower risks than surgery or conventional radiation.
  • Treatment can be completed more quickly in less than five sessions for some cancers, such as prostate cancer, compared to traditional radiation therapy, which may require as many as 40 sessions.
  • It does not require anesthesia, incisions, blood loss, or recovery time.
  • No overnight hospital stays are required.

How it works

A male patient lays on a table in the Cyberknife Center at MedStar Georgetown University Hospital awaiting treatment.

CyberKnife, also known as stereotactic body radiation therapy (SBRT), is a non-surgical solution which destroys tumors by aiming beams of radiation at them from multiple directions while sparing healthy tissues.

  • The treatment system uses multiple X-ray cameras and powerful software pinpoint the exact location of a tumor. 
  • A robotic arm uses a linear accelerator to aim high-powered beams directly at the tumor from more than 1,400 different angles.
  • The robotic arm has unparalleled flexibility. The beams can be directed even at difficult-to-reach areas of the body. 
  • The beams are so precise, they focus only on the tumor, and minimize dose to healthy surrounding tissue.

Types of cancer treated

This radiation therapy is commonly used to treat inoperable or complex tumors. It is an excellent alternative for patients who cannot or do not want to undergo surgery and for patients who have tumors in very sensitive or hard-to-reach places.

Read about the types of cancer it can be used to treat below.

  • Brain, spine, and skull-base tumors

    CyberKnife® was originally developed to treat brain and spine tumors, but without the rigid surgically attached head frame required by other radiosurgery systems. Instead, brain tumor patients who are treated with this type of therapy wear a tailor-made, lightweight, open-mesh face mask.

    The result is a much more comfortable and noninvasive experience.

    This therapy also requires only one to five treatment sessions for brain and spinal tumors, as compared to 10 to 30 sessions with traditional forms of radiation therapy.
  • Head and neck cancer

    CyberKnife® can be used to treat cancers that begin within or spread to the head and neck. Used alone or with intensity modulated radiation therapy (IMRT) and chemotherapy, it attacks tumors located in the:

    • Eye and eye socket (orbit)
    • Nasopharynx
    • Sinus
    • Nasal cavity
    • Tongue
    • Salivary glands
    • Windpipe (trachea)
    • Voice box (larynx)
    • Lymph nodes in the upper part of the neck
    • Other sites

    Before treatment, patients are outfitted with a custom-made, lightweight, open-mesh face mask to assure that the targeted tumor is in exactly the same position for each session.

  • Lung cancer

    Lung cancer can be challenging to treat with traditional radiation because your lungs naturally move as you breathe, making it challenging to focus radiation on the tumor. CyberKnife uses state-of-the-art computer and imaging technology to follow the tumor's movements—even as you breathe, making it one of the most effective treatments for:

    • Early-stage lung tumors
    • High-risk surgical patients including the elderly and those with severe emphysema
    • Previously irradiated patients whose tumors have returned

    This therapy can be used along with surgery and chemotherapy to attack metastatic lung tumors that form when cancer starts in another part of the body and spreads to the lungs.

    Before treatment, fiducial markers are placed near the lung tumor to assure accuracy in pinpointing the target while protecting surrounding healthy tissue.

  • Metastatic cancer

    Metastatic cancer implies that an initial cancer has spread to other parts of the body, such as the bone. It can be complicated to treat these types of tumors. Some, such as tumors of the brain or spine, or those wrapped around other critical structures, are often considered inoperable or surgically challenging.

    Our experts successfully treat many of these tumors using the CyberKnife® Robotic Radiosurgery system. As one of the most advanced technologies available, it can eliminate malignant and benign tumors anywhere in the body—all without the stress and recovery time needed for surgery.

  • Pancreatic cancer

    Many pancreatic tumors are virtually impossible to remove surgically. Conventional radiation is hard to deliver directly to these tumors because they are moving targets, moving as you breathe. Surrounding healthy tissue often receives unnecessary doses of radiation in these procedures.

    This therapy, with its advanced combination of computer and imaging technology, helps:

    • Identify the exact location of the pancreatic tumor
    • Coordinate with the Synchrony Respiratory Tracking System (which follows the tumor's movement as you breathe)
    • Accurately focus radiation on the tumor without affecting surrounding healthy tissue.

    Our teams are among the most experienced in the nation, and our doctors are currently researching the effectiveness of CyberKnife®.

  • Prostate cancer

    CyberKnife® may be used for treating prostate cancer for:

    • Cancer confined to the prostate and seminal vesicles
    • Prostate cancer that doesn’t meet the criteria for brachytherapy

    This prostate cancer treatment offers distinct advantages:

    • Five treatment sessions compared to the 40 or more required with other forms of radiation therapy
    • Proven results that are comparable to traditional radiation therapy as demonstrated by national and international clinical studies
    • Preserved quality of life during and after radiation treatment

    Before treatment, the prostate is implanted with fiducials—tiny gold markers that help assure accuracy in both targeting the tumor and avoiding nearby healthy tissue.

    Additionally, CyberKnife® can be used in conjunction with conventional radiation for men with high-risk or diagnosis.

    CyberKnife for Prostate Cancer: Ask Dr. Sean Collins
    play button
    Radiation Oncologist Sean Collins, MD, PhD, is director of the CyberKnife Prostate Program at MedStar Georgetown University Hospital. In this video, Dr. Collins answers commonly asked questions about CyberKnife for prostate cancer.
  • Trigeminal neuralgia

    Trigeminal neuralgia is one of the most painful neurological conditions. It is characterized by sudden, electric shock-like pain, on one side of the face. Shocks typically last a few seconds, and can occur as rarely as once a day, or as often as many times an hour.

    The location of the pain is determined by the branches of the trigeminal nerve, and can involve the forehead and corner of the eye, cheek, and corner of the nose, lower jaw, and corner of the mouth. The pain can also involve a combination of these locations.

    Some activities and environmental stimuli can trigger the pain, including:

    • Chewing
    • Talking
    • Brushing teeth
    • Cold temperature
    • Windy conditions

    With this treatment, radiation beams are delivered to the trigeminal nerve with pinpoint accuracy in order to dull the pain. There is no cutting, blood loss, or hospital stay. The entire treatment is delivered in a single, painless 45-minute session.

    Most patients experience elimination or significant reduction of their face pain within several days to weeks.

What to expect

The first time you meet with your CyberKnife team, they'll explain how treatment works and the risks and benefits for your diagnosis. Here's what you can expect after that:

  1. In some cases, your doctor will implant tiny metal markers, called fiducials, in or near the tumor, which will help to accurately guide the radiation beams if your tumor moves while you breathe.
  2. Your cancer team will use a combination of MRIs, CT scans, and 3D technology to pinpoint your tumor's size, shape, and location. This results in a detailed picture that helps them plan radiation treatment aimed at your tumor without affecting the healthy tissue around it.
  3. You'll receive three to five treatments over a week or so. Each treatment lasts approximately one hour. During treatment, you'll change into a gown and then lay down on a table. You can relax and listen to an audiobook or music. A robotic arm will move around your body, delivering radiation directly to the tumor. A tracking system will monitor the position of the tumor while CyberKnife beams remain on their target.
  4. You won't feel any pain during your session. And most patients can get back to their daily activities immediately following treatment. We'll always recommend ways to minimize possible side effects.
  5. After your last treatment, your cancer team will take more images of your tumor. They'll compare these images to the originals to see how well your tumor responded to the CyberKnife therapy. Then, they'll review your results with you in great detail, answer any questions, and suggest next steps.

Frequently asked questions

  • What is CyberKnife treatment?

    CyberKnife is a non-invasive alternative to surgery for the treatment of tumors and lesions throughout the body, utilizing highly targeted radiation therapy.

  • How does CyberKnife work?

    CyberKnife delivers high doses of radiation to the tumor with pinpoint accuracy, guided by real-time imaging and tracking systems, while minimizing damage to surrounding healthy tissues.

  • What types of conditions can be treated with CyberKnife?

    CyberKnife can be used to treat various types of cancer, including prostate, lung, brain, bones, liver, and pancreas.

  • Is CyberKnife surgery?

    No, CyberKnife is not surgery. It is a non-invasive procedure that does not require incisions, anesthesia, or hospitalization.

  • How long does a CyberKnife treatment session last?

    Treatment sessions typically last between 20 to 90 minutes, depending on the size and location of the tumor.

  • How many CyberKnife treatments are typically required?

    The number of treatments varies depending on the type, size, and location of the tumor. Most patients complete their treatment in 1 to 5 sessions, usually scheduled over consecutive days, or every other day.

  • Are there any side effects of CyberKnife treatment?

    Patients feel the same way leaving as when they arrive, and most patients can drive themselves to their appointments. Your physician will discuss potential side effects based on your specific treatment plan.

  • Is CyberKnife suitable for all patients with cancer?

    While CyberKnife can be an effective treatment option for many patients, it may not be suitable for everyone. Your radiation oncologist will assess your specific condition and determine if CyberKnife is appropriate for you.

  • What should I expect during a CyberKnife treatment session?

    During treatment, you will lie comfortably on a treatment table while the CyberKnife system delivers targeted radiation to the tumor. You will not feel any pain during the procedure.


Looking for expert cancer care?

With multiple locations throughout the region, patients have access to many of the nation’s renowned cancer specialists offering high quality care, second opinions and a chance for better outcomes close to where they live and work. Georgetown Lombardi Comprehensive Cancer Center, one of the nation’s comprehensive cancer centers designated by the National Cancer Institute (NCI), serves as the research engine allowing patients access to clinical trials that often lead to breakthroughs in cancer care.

Our locations

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MedStar Health: CyberKnife at MedStar Georgetown University Hospital

3800 Reservoir Rd., NW
CB-18 Lower Level (LL) Bles Bldg.
Washington, DC 20007

Clinical trials and research

Clinical trials

MedStar Health is conducting or participating in CyberKnife® clinical trials to learn more about pancreatic tumors, liver tumors, and lung cancer.


At MedStar Health, we are at the forefront of state-of-the-art radiation therapies. Through our partnership with the Georgetown Lombardi Comprehensive Cancer Center, we continue to investigate CyberKnife's potential benefits for patients with certain conditions.

Patient stories