CYBERKNIFE® SYSTEM

Glossary of Terms

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  • a

  • Ablative
    To remove or destroy. An ablative dose of radiation is designed to destroy the cancer cells while minimizing risk of radiation dose to surrounding healthy tissue.
  • Acoustic Neuroma
    (or vestibular schwannoma) Benign tumor that develops on the balance (vestibular) and hearing, or auditory (cochlear) nerves leading from your inner ear to the brain. Pressure from the tumor can lead to imbalance, hearing loss and ringing in the ears.  
  • Angiogram
    Diagnostic test using x-ray or computer imaging to view the blood vessels and blood flow.
  • Arteriovenous Malformation
    (AVM) Tangle of abnormal blood vessels in the brain, weakening and possibly rupturing affected arteries and veins.  
  • Audiogram
    Graph or chart that shows the softest sounds a person can hear at different pitches or frequencies, it measures the degree of hearing loss.
  • b

  • Benign Tumor
    A tumor that is not cancerous or malignant. It does not spread to other parts of the body, but can be equally as dangerous as a cancerous or malignant tumor if it is compressing vital structures, such as blood vessels, nerves, or over producing certain hormones.
  • BiCROS
    Bilateral Microphones with Contralateral Routing of Signal – Hearing aid recommended for people with hearing loss in both ears, but one ear hears substantially “better” than the other.
  • Brachytherapy
    (also called internal radiation) Is a form of radiotherapy where a sealed radiation source is placed inside or next to the area requiring treatment. 
  • c

  • Cerebrospinal Fluid
    Clear, colorless body liquid surrounding the brain and spinal cord; serving as a barrier against shock.
  • Chemotherapy
    Cancer treatment that is administered through the use of drugs that are injected into the body, taken orally over a period of time, administered by infusion or through the skin. This is a form of systemic therapy – i.e., as the drugs circulate in the bloodstream, the entire body is affected.
  • CNS
    Central Nervous System — The brain and spinal cord. It gathers information from all over the body and coordinates activity.
  • Critical Structures
    Refers to normal tissues near the tumor. Damage to critical structures can often lead to problems for patients and side effects. For example, the spinal cord is the primary critical structure of concern when treating spinal lesions.
  • CT
    Computed Tomography — A diagnostic imaging technique that uses computerized X-ray imaging procedure to create detailed 3D images of tissues and structures in the body. A dye, or contrast agent, may be injected into the patient to highlight structures and abnormalities.
  • e

  • External Beam Radiation Therapy
    The use of radiation delivered from outside the body to kill cancer cells or shrink tumors.
  • Extracranial
    Refers to any location of the body “outside of the brain”. Examples of extracranial sites include the spine, lung, pancreas, and other areas of the body.
  • f

  • Fiducials
    Fiducials are markers that are placed around a tumor for the purpose of better identifying and tracking a tumor on an X-ray.
  • g

  • Gleason Score
    A grading system to determine the cancer’s aggressiveness.  The Gleason score usually ranges from 6 to 10. The lower the Gleason score, the more the cancer cells look like normal cells. The Gleason score is used to help identify treatment options and determine the patient’s prognosis (outcome).
  • Glioma
    Tumor in the brain or spinal cord that starts in the glial cells.
  • h

  • Hydrocephalus
    The buildup of fluid in cavities in the brain, which puts pressure on the brain and leads to a wide range of symptoms, including headaches, nausea, imbalance, incontinence and more.
  • Hypofractionation
    Dividing the total dose of radiation into multiple smaller doses (usually administered daily), thereby permitting the surrounding exposed healthy tissue time to repair.
  • Hypofractionation
    Radiation treatment in which an effective and high dose is given in less treatment sessions or fractions compared to conventional radiation therapy.
  • i

  • Immunotherapy
    (also called biologic therapy): Type of cancer treatment that helps your immune system fight cancer and other diseases. Immunotherapy treatments use substances made by the body or in a laboratory to improve or restore immune system functionality.
  • Intracranial
    Refers to “inside the skull” or brain.
  • Irradiation
    The use of radiation to kill cancer cells or shrink tumors.
  • l

  • Linear Accelerator
    (LINAC) Commonly used device that delivers external beam radiation treatments for patients with cancer. It delivers high-energy x-rays or electrons to the region of a patient’s tumor. 
  • m

  • Malignant Tumor
    A cancerous tumor. Abnormal collections of cells that can invade and destroy nearby and distant tissues and organs.
  • Medical Dosimetrist
    A member of the radiation oncology team who has knowledge of the overall characteristics and clinical relevance of radiation oncology treatment machines and equipment. Ensures the radiation treatment delivers the most lethal dose to the tumor with the fewest side effects to healthy organs.
  • Medical Physicist
    Professional with education and specialist training in the concepts and techniques of applying physics in medicine.
  • Melanoma
    A serious form of skin cancer that begins in the cells that control the pigment of your skin.
  • Meningiomas
    Tumors that originate in the membranes surrounding the brain and spinal cord.
  • Metastases
    The spread of cancer cells to new areas of the body. A metastatic tumor has spread from the place where it first formed to another part of the body. 
  • Metastasized
    The spread of cancer cells to new areas of the body. A metastatic tumor has spread from the place where it first formed to another part of the body. 
  • MRI
    Magnetic Resonance Imaging — An imaging technique that uses magnetic fields rather than X-rays to create 3D images of structures in the body. An MRI generally provides more detailed images of soft tissue anatomy (as opposed to bone) compared to a CT scan. A dye may be injected prior to the scan to improve visualization of many tumors. MRI scans are painless.
  • Multi-modality
    Combining multiple methods to treat cancer. For example, using radiotherapy and surgery.
  • n

  • Necrosis
    Death of cells in body tissue or organs because of injury, disease or failure of the person’s blood supply. 
  • Neoadjuvant Therapy
    Treatment administered as a first step to shrink a tumor before the main treatment, usually surgery, is given.
  • o

  • Orthostatic Hypotension
    (also called postural hypotension) Type of low blood pressure that happens when standing up after sitting or lying down, leading to feelings of dizziness, lightheadedness and faintness.  
  • p

  • PET
    Positron Emission Tomography – An imaging technique that provides a picture of cellular activity by measuring positrons emitted from injected substances "labeled" with a radioactive marker. PET scans help determine if a lesion has increased activity that may be a sign of rapid cell growth indicating a tumor.
  • Pituitary Adenoma
    Benign, slow-growing tumors or growths on the pituitary gland.
  • PSA
    Prostate Specific Antigen – Protein produced by the prostate gland found in the blood. Higher levels of PSA in the blood may indicate there is a problem with the prostate (e.g., prostate cancer, an infection, inflammation of the prostate gland). 
  • PSA Test
    The PSA test measures the level of PSA in the blood.
  • r

  • Radiation Oncologist
    Physician who has special training in using radiation to treat cancer.
  • Radiation Therapist
    Administers radiation treatments for cancer patients.
  • Radical prostatectomy
    An operation to remove the prostate gland and tissues surrounding it. 
  • Radiologist
    Medical doctor specializing in medical imaging to support diagnosis and treatment of various diseases. 
  • Radiotherapy
    (also called radiation therapy) Cancer treatment that uses radiation to kill cancer cells or reduce tumor size. 
  • s

  • SABR
    Stereotactic Ablative Radiotherapy — Another term for SBRT (Stereotactic Body Radiation Therapy).
  • SBRT
    Stereotactic Body Radiation Therapy — A radiation therapy approach which delivers high dose radiation to a target within the body, in either a single treatment session or up to no more than five treatment sessions. Each session is typically referred to as a “fraction.”
  • Seed Implants
    Form of radiation therapy for prostate cancer. The terms "brachytherapy" or "internal radiation therapy" might also be used to describe the procedure.
  • SRS
    Stereotactic Radiosurgery — A non-surgical radiation therapy approach used to treat functional abnormalities and small tumors in the brain. High-dose, precisely-targeted radiation is delivered in fewer treatment sessions than conventional radiotherapy, typically just 1 to 5 sessions, which can help preserve healthy tissue.
  • Stereotactic
    “Stereo” makes reference to one’s position within 3-dimensional space. Stereotaxy or stereotaxis is the science and practice of precisely locating a tumor within 3D space. Also known as Stereotaxis or Stereotaxy.
  • t

  • Toxicity
    The degree a substance can cause harm to humans.
  • Treatment Planning
    In radiotherapy, it is the process in which a team consisting of radiation oncologists, radiation therapists, medical physicists and medical dosimetrists plan the appropriate radiotherapy treatment for a patient with cancerous or non-cancerous tumors.
  • Trigeminal Neuralgia
    Chronic pain condition that affects the trigeminal nerve, which carries sensation from the face to the brain. Patients can experience excruciating pain in the areas of the face where the branches of the nerve are distributed including the upper and lower jaws, scalp, forehead, eyes, nose and lips.
  • u

  • Urologist
    Physician who specializes in diseases of the urinary organs in females and the urinary and sex organs in males.
  • v

  • Vascular Malformations
    General term for vascular anomalies of veins, lymph vessels and/or arteries. Often congenital (present at birth) and can cause functional or cosmetic problems.