Frequently Asked Questions
What is radiation therapy?
Radiation therapy uses focused beams of intense energy to destroy cancer cells and shrink or control the growth of tumors. Radiation therapy works by preventing targeted cells from multiplying. The objective of radiation therapy is to destroy the harmful cells while minimizing damage to healthy cells.
Radiation may be recommended as an alternative to surgery or in addition to surgery or other therapies. It also can be used to manage pain caused by lesions. Radiation can be delivered internally or externally. This FAQ focuses on one type of externally delivered radiation therapy.
What is radiosurgery?
Radiosurgery is a form of radiation therapy that uses precisely targeted radiation to destroy tumors. Radiosurgery is non-invasive – there is no cutting involved. The term “surgery” refers to the high level of precision of the energy beams. Radiosurgery is commonly used by neurosurgeons to treat conditions within the brain and spine. Stereotactic body radiation therapy (SBRT) is a treatment that uses precisely targeted radiation to destroy tumors located outside the brain and spine. The CyberKnife® System was designed for both high-precision radiosurgical and SBRT procedures.
What happens to cancer cells following treatment? Do they remain in a patient’s body?
Radiation destroys tumor cells so they cannot regenerate, but it does not remove the affected cells from the body as surgery does. With effective treatment, the tumor may shrink or disappear entirely, or its growth may be stopped. Radiation therapy works by damaging the genetic material within the cancer cells and limiting their ability to successfully reproduce. When these damaged cancer cells die, the body naturally eliminates them.
How long does each treatment take?
CyberKnife treatments typically last between 30 to 90 minutes. The duration of a CyberKnife treatment session is largely dependent on the number of beams used to treat the tumor and the degree of motion exhibited by the target. Treatment plans with higher number of radiation beams delivered to moving targets will take longer than lower beam plans delivered to static targets because of the time needed to ensure high-precision delivery. Recent technological advances, including the availability of a beam-shaping multileaf collimator, will make treatment times significantly faster while achieving the same or better radiosurgical precision.
What is the CyberKnife® System?
The CyberKnife System delivers non-invasive treatment for cancerous and non-cancerous tumors anywhere in the body, including the prostate, lung, brain, spine, head and neck, liver, pancreas and kidney, where radiation is indicated. Using the CyberKnife System, your physician precisely targets the tumor, safely delivering radiation with sub-millimeter accuracy, while minimizing radiation exposure to healthy organs and tissues.
What types of cancers or areas of the body can the CyberKnife® System treat?
The CyberKnife System has been successfully used to treat conditions throughout the body, including prostate, lung, brain, spine, head and neck, liver, pancreas and kidney.
What are the patient benefits of treatment with the CyberKnife® System?
- No surgical incision
- Generally pain free
- Does not require general anesthesia or hospitalization
- Treatments typically completed in one to five treatment sessions
- Precise treatments sparing healthy surrounding tissue, providing in most cases:
- Little to no recovery time
- Immediate return to daily activities
- Minimal side effects
What are the side effects associated with treatment?
Side effects of CyberKnife treatment are usually mild and temporary, and may include nausea and fatigue. As with any radiation treatment, the side effects also can be severe in some patients and lead to permanent injury or even death. Talk to your doctor to determine if treatment with the CyberKnife System is right for you.
Safety Information: Most side effects of radiotherapy, including radiotherapy delivered with Accuray systems, are mild and temporary, often involving fatigue, nausea, and skin irritation. Side effects can be severe, however, leading to pain, alterations in normal body functions (for example, urinary or salivary function), deterioration of quality of life, permanent injury and even death. Side effects can occur during or shortly after radiation treatment or in the months and years following radiation. The nature and severity of side effects depend on many factors, including the size and location of the treated tumor, the treatment technique (for example, the radiation dose), the patient's general medical condition, to name a few. For more details about the side effects of your radiation therapy, and if treatment with an Accuray product is right for you, ask your doctor.
How many treatments are usually needed?
SRS or SBRT, including CyberKnife radiosurgery, is typically delivered in one to five sessions, usually completed within a week.
Will insurance cover the procedure?
CyberKnife radiosurgery for treatment of cancers, per its FDA clearance, is covered by most payers in most U.S. geographies. Patients should always check their insurance policy relative to particular diagnosis and treatment, and if required, obtain prior authorization from their insurance companies once a treatment option is determined. The business office of the CyberKnife center can usually be of assistance with whether your condition is covered by your payer. In some cases, you and your physician may decide to appeal any denial of treatment. All insurers have a process for appeal.
If you live outside of the United States, typically the CyberKnife center that you choose for treatment can answer coverage questions.
How is radiosurgery with the CyberKnife® System different from traditional radiation therapy treatment?
All external-beam radiation devices face the same fundamental issues:
- the radiation beam needs to enter and exit the body somewhere
- the device design limits how radiation beams can be directed into the body
- the device needs to deliver some radiation to tissue surrounding the tumor because of tumor motion
The CyberKnife technology addresses these issues in a completely different manner from any other device.
With the CyberKnife System, precision matters. The robotic design of the CyberKnife System enables clinicians to find the best locations and angles for radiation to enter and exit the body, thus maximizing dose to the target while minimizing exposure to healthy tissue. The robotic design also enables the system to move anywhere the tumor moves, keeping radiation precisely on target throughout the treatment.