What is Radiation Therapy


What is Radiation Therapy?


images-1Radiation therapy is the use of high energy xrays, that are used to shrink and kill cancer cells.  Radiation is delivered with radioactive materials placed in the body, called Brachytherapy, or externally by a machine outside the body, also known as external beam radiation therapy.  Systemic radiation therapy will use a radioactive substance via the mouth or into a vein that will travel in the blood to tissues throughout the body.  Brachytherapy is done with small radioactive seeds placed directly into a body cavity or with the use of an applicator.  Radioactive seeds decay slowly over a period of time.  This type of treatment is an option for certain cancers such as prostate cancer.  This is generally a one or two day procedure.  If an applicator is used, it is placed in the body for a short period of time and then removed.  This treatment takes approximately 30 minutes and is done in one to ten sessions. 

In general, external beam radiation therapy is given in smaller doses over a period of 5-6 weeks on a daily basis.   The total dose of radiation and the number of treatments can vary, based on:

  • The size and location of your cancer
  • The type of cancer
  • The reason for the treatment
  • Your general health
  • Any other treatments you are getting


How does Radiation Therapy Kill the Cancer Cells?


images-6The genetic make up of cancer cells  are damaged with radiation. When these cancer cells are damaged they then stop dividing and die.  These damaged cells are broken down and then eliminated naturally.

Does Radiation only Kill Cancer Cells?


Radiation can also damage normal cells, which can lead to side effects.  However, when radiation therapy is initiated, a precise mode or radiation treatment is planned, mapped out and executed in a manner that will affect any normal cells as little as possible and be effective in killing the cancer cells. 

Why do Patients Receive Radiation Therapy?


Radiation therapy may be used alone or in combination with surgery or chemotherapy.  It could also be used with both surgery and chemotherapy.  Radiation therapy is utilized with the intent to cure the cancer itself.  Palliative radiation therapy is utilized with the intent to not cure the cancer but to relieve symptoms which eases the suffering.  Some examples of palliative radiation therapy are:

                 *  Radiation given to the brain to shrink tumor from cancer cells that have spread to the brain from another part of the body                               (metastases).

                 *  Radiation given to shrink a tumor that is pressing on the spine or growing within a bone, which can cause pain.

                 *  Radiation given to shrink a tumor near the esophagus, which can interfere with a patient’s ability to eat and drink.