Radiation Therapy

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Radiation therapy uses beams of intense energy such as  high-powered x-rays particles or radioactive seeds to kill cancer cells. It damages cancer cells and prevents them from growing and dividing. This leads to cell death. This procedure directly damages the DNA of the cancer cells or create charged particles (free radicals) within these cells that can in turn damage the DNA. Radiation therapy can destroy a few normal cells during the procedure.


Radiation therapy is used to fight about every type of cancer. Sometimes it is the only treatment that a patient needs. Other uses of this therapy include

  • shrinking a tumor before surgery – neoadjuvant therapy
  • stop the growth of remaining cancer cells after surgery – adjuvant therapy
  • treat cancers that cannot be removed by surgery
  • alleviate cancer symptoms in the case of an advanced stage cancer
  • used in combination with other treatments to destroy cancer cells


External beam radiation : This is the most common type used.  It carefully directs high-powered x-rays or particles directly at the tumor from outside of the body.

Internal beam radiation : This is placed inside your body. When radioactive seeds are placed directly into or near the tumor, it is called brachytherapy. It is mostly used for prostate cancer and less often for other cancers such as lung or breast cancers. In another type, radiation is received by   drinking , swallowing a pill, or through an IV. It travels throughout the body seeking and killing cancer cells. Some types of lymphomas and thyroid cancers uses this type of internal beam radiation.


Side effects of radiation therapy depends on the which part of the body is being exposed to the radiation and the dose of radiation used. External beam radiation may cause hair loss, burning of skin, thinning of skin or shedding of the outer layer of the skin. Other side effects depend on the part of the body receiving the radiation

 body PART  BEING treated   side effects
Any part of the body Hair loss at treatment site, skin irritation  and redness at treatment site, fatigue
Mouth and neck Dry mouth, nausea, difficulty swallowing, mouth pain, changes in the way food tastes
Abdomen  Nausea, vomiting, diarrhea
Chest Difficulty swallowing, cough, dry scratchy throat, breathlessness, breast or nipple soreness
Pelvis Incontinence, bladder irritation, frequent urination, sexual problems in both men and women, rectal bleeding, diarrhea


After the procedure, patients will have to undergo a series of imaging tests to see how the cancer responded to radiation therapy.Some cancers respond suddenly while others take a few weeks or even months.

Side Effects of Radiation Therapy.American Society of Clinical Oncology (ASCO). http://www.cancer.net/all-about-cancer/cancernet-feature-articles/treatments-tests-and-procedures/side-effects-radiation-therapy .Accessed January 2, 2014

Radiation therapy. National Library of Medicine. http://www.nlm.nih.gov/medlineplus/ency/article/001918.htm. Accessed January 2, 2014

Radiation Therapy. American Cancer Society.http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/radiation/radiation-landing. Accessed January 2 , 2014

Radiation therapy. Mayo Foundation. http://www.mayoclinic.com/health/radiation-therapy/MY00299 . Accessed January 2, 2014

Radiation Therapy for Cancer. National Cancer Institute. http://www.cancer.gov/cancertopics/factsheet/Therapy/radiation. Accessed January 2 , 2014

The American Heritage® Stedman’s Medical Dictionary. Retrieved January 2014 from Dictionary.com website.http://dictionary.reference.com.

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