Side effects of breast radiotherapy


There are two types of side effects linked to breast radiation therapy:

  • Early/acute side effects that mainly concern the skin (redness, itching, peeling). They appear during the treatment and disappear after the treatment end. Most patients will develop these side effects.
  • Late side effects, mainly fibrosis. This skin retraction appears between 3 months and 3 years after the treatment end and will not disappear. These complications are rare: less than 10% of patients will develop them. Specific management will be put in place to limit their impact on the patient’s quality of life.

Like for all radiation therapy side effects, breast irradiation can lead to:


  • acute side effects that usually appear during the treatment and disappear within 3 months after the treatment end;
  • late side effects that appear between 3 months and several years after the treatment end and do not disappear.


The side effect intensity and the risk of occurrence vary greatly among patients, and sometimes also in function of the radiotherapy technique used.


Acute side effects essentially concern the skin. From the third week of treatment, the patient may observe the appearance of epithelitis (or epidermitis) in the breast or lymph node areas (armpits and collarbones). This is an inflammation of the skin that becomes red, like a sunburn. This inflammation can be dry or exudative (oozing), sometimes associated with desquamation (skin that “peels”).

Edema of the breast (swelling) and itching or tingling are sometimes observed. Patients undergoing irradiation of the subclavicular and supraclavicular lymph nodes may experience swallowing problems, and rarely nausea. These symptoms are caused by radiation-induced esophagitis because the esophagus is close to the irradiated area. The radiation oncologist will prescribe drugs to alleviate these symptoms. These side effects do not have long-term consequences and they disappear progressively after the treatment end.


Late side effects are much rarer, and occur in less than 10% of patients. They concern essentially the skin and appear several months to several years after the treatment end. The most frequent late side effect is fibrosis, a retraction of the breast skin that can lead to breast asymmetry and sometimes pain. Changes in skin color (melanoderma) also can be observed.