Common Terms

Cancer treatment options and learning the vocabulary of common terms can be challenging.  Here some general definitions for common terms you might hear while exploring your treatment options.

Brachytherapy: Radiation therapy that is the process of placing a radioactive substance close to a tumor either through a body cavity or an incision in the skin. This allows a higher dose of radiation to be placed in or near the tumor.

Bragg Peak: The proton is very fast when it enters the patient’s body and deposits only a small dose on its way. The absorbed dose increases very gradually with greater depth and lower speed, suddenly rising to a peak when the proton is ultimately stopped. This is known as the Bragg peak. The behavior of the proton can be precisely determined and the beam can be directed so the Bragg peak occurs exactly within the tumor site. Immediately after this burst of energy, the proton completely stops to irradiate.

Conventional Radiation Therapy: The most common type of cancer treatment, in which electrons or x-rays are used to target cancerous areas of the body.

Entrance Dose: The dose of radiation that is absorbed by healthy tissue before the radiation actually reaches its intended target, the tumor.

Electron: The particles from an atom that are deposited during traditional radiation therapies, effective for tumors that lack depth.

Exit Dose: The dose of radiation that is absorbed by healthy tissues after the radiation actually reaches the tumor. With the use of proton therapy, protons enter the tumor and then stop, eliminating this exit dose.

Local Therapy: Cancer treatment that impacts the tumor itself and the areas closely nearby.

Metastasize: The result of cancer cells splitting from a tumor and creating a new tumor or malignant growth at a distance from primary site of cancer.

Pencil Beam: Feature of the proton therapy system from which the protons are delivered in a targeted, precise dose.  It is a narrow, controlled beam of proton particles administering radiation.  This can help minimize negative side effects.

Protons: The particles from an atom that have a positive charge.

Proton Therapy: An advanced form of radiation therapy that uses a single beam of high-energy protons, rather than X-rays, to treat various forms of cancer, delivering precise treatment to tumors in a way that can reduce side effects and cancer recurrence.

Radiation Therapy: Cancer treatment that involves the use of x-rays or radiation, including proton therapy.

Simulation Visit:  The use of a computerized tomography (CT) scan, a positron emission tomography (PET) scan or a magnetic resonance imaging (MRI) to determine the ideal treatment plan for proton therapy patients.

Toxicity: Damage to normal, healthy tissue as a result of exposure to radiation during treatment.

Tumor: Caused by a concentration of cells, it is a mass that may be benign, lacking the ability to metastasize and spread to other parts of the body, or malignant, able to spread and collect in additional areas of the body.