Radiation therapy for cancer pain

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Radiation therapy for cancer pain

Treatment Overview

Radiation therapy is the use of X-rays to destroy cancer cells and shrink tumours. Radiation damages the genetic material of cells in the area being treated, leaving the cells unable to continue to grow. Although radiation damages normal cells as well as cancer cells, the normal cells can repair themselves. The cancer cells cannot.

Radiation is also used to control pain by destroying a growing tumour that is invading or interfering with normal tissue, such as when a tumour presses on bones, nerves, or other organs.

What To Expect After Treatment

Radiation is delivered in one of two ways:

  • Brachytherapy, or internal radiation therapy, inserts radioactive material directly into or near the tumour. Removable radiation sources are inserted with needles or small thin tubes. Sometimes the material is left in your body (permanent brachytherapy). In this case, small beads that contain the radioactive material are inserted into the tumour. The beads release radiation at the site of the tumour over a few days or weeks, after which they are no longer radioactive.
  • External beam radiation therapy uses a beam of radiation directed at the tumour. After the area of cancer is identified, a small ink tattoo is fixed on the skin over the area of cancer so that the radiation beam can be focused on the same spot for each treatment. It is necessary to focus the radiation beam on the cancer cells and to shield nearby healthy tissue from the radiation. External beam radiation therapy is usually done in multiple treatments, usually once a day for several weeks or longer.

Why It Is Done

Radiation therapy is used to control pain when a growing tumour invades or interferes with normal tissues, such as bones, nerves, or other organs.

How Well It Works

Radiation therapy can reduce pain by shrinking a tumour. Often only a single dose of radiation is needed to relieve pain.1


Side effects are common with radiation therapy and may depend on what area of the body receives radiation. Side effects generally go away after radiation therapy is over. Side effects can include:

  • Fatigue.
  • Hair loss near the treated area.
  • Nausea, vomiting, and diarrhea.
  • Loss of appetite.
  • Painful urination.
  • Skin darkening in the area exposed to a beam of radiation, which can be permanent.
  • Vaginal dryness in women and erection problems in men (with pelvic radiation).

What To Think About

While radiation therapy may not cure the cancer that is causing pain, it may reduce symptoms, decrease the spread of the disease, and help you live longer.

Complete the special treatment information form (PDF) (What is a PDF document?) to help you understand this treatment.



  1. National Cancer Institute (2009). Pain PDQ—Health Professional Version. Available online: http://www.cancer.gov/cancertopics/pdq/supportivecare/pain/healthprofessional.


By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer Michael Seth Rabin, MD - Medical Oncology
Specialist Medical Reviewer Andrew Swan, MD, CCFP, FCFP - Family Medicine
Last Revised February 1, 2010

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.