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Radiotherapy: side effects. A brief overview of the most common ones.

Radiation therapy effectively treats many types of cancer but, just as with other cancer treatments, it often causes side effects. The side effects of radiation therapy, as well as those of hormone therapies and treatments, vary from person to person. This is because they depend on the type of cancer, its location, the dose of radiation therapy, the patient’s general health, and other factors. It is important to talk to your care team about any side effects that may occur. This is to put the team in a position to be able to find the most appropriate way to help the patient tolerate them.

But why does this type of therapy cause side effects? High doses of radiation therapy are used to destroy cancer cells. Side effects of radiation therapy come from damage to healthy cells and tissues near the treatment area.(Find out how ONCOS takes action to prevent skin side effects).

In recent years, major advances have been made in radiation therapy research that have made it more precise. This has resulted in fewer side effects from radiation therapy, compared with therapy techniques used in the past.


Radiation therapy aimed at treating cancer causes some side effects, among them:

  • Changes in the skin, such as dryness, itching, blistering or peeling; Discover the ONCOS catalog for skin problems.
  • Fatigue, described as a feeling of tiredness or exhaustion;
  • In the case of radiotherapy aimed at the head or neck, dry mouth, gum sores, difficulty swallowing, jaw stiffness, nausea, hair loss, a type of swelling caused by lymphedema, and tooth decay may occur;
  • In the case of chest-targeted therapy, difficulty swallowing, shortness of breath, breast or nipple pain, shoulder stiffness, and radiation fibrosis may occur;
  • In case of radiation therapy targeted to the abdomen, loss of appetite, nausea and vomiting, intestinal cramps, soft stools or diarrhea may occur;
  • In the case of radiation therapy targeted to the pelvis, soft stools or diarrhea, rectal bleeding, incontinence, bladder irritation, erectile dysfunction in men, and amenorrhea, or absence of menstruation, in women, who may also experience menopausal symptoms such as vaginal itching, dryness, and burning may occur.


How long side effects last: some useful information.

Side effects of radiation therapy often begin during the second or third week of treatment. Some may last for several weeks after the final treatment. The health care team is able to help prevent and, even better, alleviate many side effects. Prevention and treatment of radiation therapy side effects is a very important part of treatment. They are what is called palliative care or supportive care.

In some, limited cases, long-term side effects may occur due to radiotherapy. For example, in very rare circumstances, a new cancer (second primary cancer) other than the first one treated with radiation may develop years later.

It is always critical to talk to your medical team about what you can and should expect from treatment. Above all, regularly inform the health care team about how you feel during and after the treatment itself.