You may encounter new terms during your treatment. Our glossary will give you a better understanding of them.

Advance Directive: A legal document that tells the doctor and family what a patient wants for future medical care in the event that he or she becomes unable to make his or her own decisions. This may include whether to start or stop life-sustaining treatments. See also living will.

Benign: A tumor that is not cancer or malignant.

Bone Scan: A diagnostic imaging test to determine if the cancer has spread to the bones.

Cancer: An abnormal group of cells that grows uncontrollably and spreads, if untreated, throughout the body.

Cancer Care Team: Healthcare professionals who work together to find, treat, and care for people with cancer. It may include: primary care physicians, pathologists, oncology specialists (medical oncologist, radiation oncologist), surgeons (including surgical specialists such as urologists, gynecologists, neurosurgeons, breast surgeons, etc.), nurses, oncology nurse specialists, oncology nurse navigator, advanced practice providers, and oncology social workers.

Cancer Cell: An abnormal cell that grows uncontrollably and has the potential to spread throughout the body.

Cancer-Related Fatigue: An unusual and persistent sense of tiredness associated with cancer or cancer treatments. It can be overwhelming and interfere with everyday life.

Carcinogen: A substance that causes cancer. For example, tobacco smoke contains many carcinogens that greatly increase the risk of lung cancer.

Catheter: A thin, flexible tube through which fluids enter or leave any part of the body. A catheter may be used to drain urine (also called a Foley catheter), or to deliver medications.

Cell: The basic unit of which all living things are made. Normal cells replace themselves by splitting and forming new cells (this process is called mitosis). When cancer is present, the process that controls the formation of new cells and the death of old cells is disrupted, thus leading to uncontrolled growth.

Clinical Staging: By examining all diagnostic studies, biopsy or  pathology results, and through physical examination, the physician team will estimate the extent, or spread, of the cancer.

Clinical Trials: Research studies used to test new drugs or other treatments. They compare current and standard treatments with others that may or may not be better. Before a new treatment can be used on people, it is studied in a lab. If the lab study suggests the treatment will work, the next step is to test its value in patients. The main questions the researchers want to answer are:

  • Does the treatment work?
  • Does it work better than what we are currently using?
  • What side effects does it cause?
  • Do the benefits outweigh the risks?
  • Which patients are most likely to find this treatment beneficial?

Computed Tomography (CT): X-ray images of the body taken from many different angles. These images are combined by a computer to make cross-sectional pictures of internal organs. This is usually a painless procedure that can be done in an outpatient clinic, except for the injection of a dye (needed in some but not all cases). It is often referred to as a “CT” or “CAT” scan.

Cone beam CT: Cone beam computed tomography provides 3-D volumetric imaging. Put simply, it gives your clinicians a better view of your tumor for a more precise treatment.

Cyclotron: A machine that takes protons extracted from hydrogen atoms and accelerates them to almost the speed of light.

Diagnosis: To identify a disease by its signs or symptoms, by using imaging tests, physical exam, and laboratory findings.

Dietary Supplement: These are products such as a vitamins, minerals, or herbs. They are intended to improve health but not to diagnose, treat, or cure disease. Some supplements may interfere with your cancer treatment. Always discuss taking dietary supplements with your physician.

Distant Cancer: Cancer that has spread far from its original location or primary site to distant organs or lymph nodes. This can be called a distant metastases. See also primary site.

Dosimetrist: Your care team member who plans and calculates the proper radiation dose for cancer treatment.

External Beam Radiation Therapy: External radiation is focused from a source outside the body on the area affected by the cancer. It is similar to getting a diagnostic X-ray, but for a longer time period.

Fatigue: An overall weakness or feeling of exhaustion.

Fixed-beam room: A dedicated room for the delivery of a horizontal proton beam that is fixed in place.

Hormone: A chemical substance released by the endocrine glands such as the thyroid, adrenal, or ovaries, into the body. Hormones travel through the bloodstream and are responsible for various body functions. Testosterone and estrogen are examples of male and female hormones.

Hormone Therapy: This may be the administration of hormones or administration of drugs that prevent the body’s ability to produce hormones to control the growth of the cancer.

Hot Flush: This can be a sudden brief feeling of body warmth, along with flushing of the skin and sweating, common during menopause and hormone therapy. Also called hot flash.

Immune System: This is the complex system that protects the body from infection. It may also help the body fight some cancers.

Invasive Cancer: This is when cancer has spread beyond the layer of cells where it first developed and has grown into nearby tissues.

Isocentric gantry room: A treatment room in which the gantry rotates the beam angle 360 degrees around the patient.

Lesion: Often used to describe a tumor, it is a change in body tissue. It can also be used to describe a change in the appearance or texture of skin, such as an open sore, scab, or discolored area.

Living Will: A legal document that allows a patient to decide what should be done if he or she becomes unable to make healthcare decisions. It is a type of advance directive. See also advance directive.

Lymph: The clear fluid that flows through the lymphatic vessels. It contains cells known as lymphocytes. These cells help to fight infection and may have a role in fighting cancer. See also lymphatic system, lymph node.

Lymph Nodes: These are small bean-shaped collections of immune system tissue, such as lymphocytes, found along lymphatic vessels. They remove cell waste, germs, and other harmful substances from lymph. See also lymph, lymphatic system.

Lymphatic System: The tissues and organs (including lymph nodes, spleen, thymus, and bone marrow) that produce and store lymphocytes. This includes the channels that carry the lymph fluid. Invasive cancers can sometimes spread (metastasize) through lymphatic vessels (channels) to lymph nodes.

Magnetic Resonance Imaging (MRI): An imaging diagnostic test that uses a powerful magnet to send radio waves through the body. The images appear on a computer screen and appear similar to X-rays.

Malignant Tumor: A tumor or mass of cancer cells that invades surrounding tissues or spreads (metastasizes) to distant areas of the body.

Metastasize: The spread of cancer cells to one or more sites in the body, often by way of the lymph system or bloodstream.

Metastatic: Describes cancer that has spread from the primary site (where it started) to other structures or organs, either nearby and/or far away (distant).

Oncology: The branch of medicine concerned with the diagnosis and treatment of cancer.

Osteoporosis: The thinning of bone tissue that causes less bone mass and weaker bones. Osteoporosis can cause pain, deformity (especially of the spine), and broken bones. This condition is common among postmenopausal women and patients undergoing hormone therapy.

Pencil-beam scanning: Also known as spot-scanning proton therapy. It is the process of using an ultra-fine proton beam measuring only a few millimeters across each layer of the tumor. It’s the ideal technology for irregularly shaped tumors near sensitive areas.

Positron Emission Tomography (PET) Scan: A PET scan is a type of imaging test that helps doctors see how the organs and tissues inside your body are functioning. The test involves injecting a very small dose of a radioactive chemical, called a radiotracer, into the vein of your arm. The tracer travels through the body and is absorbed by the organs and tissues being studied. Next, you will be asked to lie down on a flat examination table that is moved into the center of a PET scanner– doughnut-like shaped machine. This machine detects and records the energy given off by the tracer substance and, with the aid of a computer, this energy is converted into three-dimensional pictures.

Primary Site: The site where the cancer originated or first started growing. See also distant cancer.

Proton Therapy: Proton beam therapy is an advanced type of radiation therapy aimed at destroying cancerous cells using protons. The treatment offers submillimeter precision that delivers high-energy proton beams directly to tumors, minimizing damage to surrounding healthy tissue.

Radiation Oncologist: This physician specializes in using radiation to treat cancer.

Radiation Therapist: This certified professional is trained to work the equipment that delivers radiation therapy.

Radiation Therapy: The process of treating cancer with high energy rays (such as X-rays) to kill or shrink cancer cells. It can be external radiation, from outside the body, or internal radiation by placing radioactive materials directly in the tumor (brachytherapy). Radiation therapy has many uses including to shrink the cancer before surgery, to destroy any remaining cancer cells after surgery, or as the main treatment. It may also be used as palliative treatment for advanced cancer by treating bone metastasis. 

Side Effects: Any unwanted effects of treatment such as fatigue.

Staging: By examining all diagnostic studies, biopsy or pathology results, and physical exam, the physician team will estimate the extent of or spread of the cancer.

Tissue: This is a collection of cells, united to perform a particular function.

Treatment plan: A scheduled set of activities and procedures your clinicians create to treat your cancer.

Tumor: Refers to an abnormal lump or mass of tissue. Tumors can be benign (non-cancerous) or malignant (cancerous).

Tumor markers: Substances that can be found in the body when a person has cancer. These substances are usually made by cancer cells, but are sometimes normal cells as well.

Ultrasound: A means of imaging in which high-frequency sound waves are used to outline a part of the body. These sound wave echoes are picked up and displayed on a television screen. Also called ultrasonography.

Watchful Waiting: Also called “active surveillance,” it simply means to have no treatment for a cancer. Instead the progression of the cancer is closely monitored.

X-rays: A form of radiation that when used at low levels, produces an image of the body on film, and at high levels it is used to destroy cancer cells.

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