You are here: 

Potential side effects of radiation therapy for mesothelioma

Side effects can occur with any type of treatment for mesothelioma, but not everyone has them or experiences them in the same way. Side effects of radiation therapy will depend mainly on:

  • size of the area being treated
  • specific area or organs being treated
  • total dose
  • treatment schedule
  • if other treatments, such as chemotherapy, are also given

Radiation therapy damages cancer cells, but healthy cells in the treatment area can also be damaged, even though steps are taken to protect them as much as possible. Different cells and tissues in the body tolerate radiation differently.

Side effects can happen during, immediately after or a few days or weeks after radiation therapy. Most side effects go away after radiation therapy is completed. However, some side effects may persist for a while because it takes time for healthy cells to recover from the effects of radiation therapy. Late side effects can occur months or years after radiation therapy. Some side effects may last a long time or be permanent.

It is important to report side effects to the healthcare team. Many side effects can be relieved by medications, a change in diet or other measures. Doctors may also grade (measure) how severe certain side effects are. Sometimes radiation therapy treatments need to be adjusted if side effects are severe.

Skin reactions

Skin reactions occur because external beam radiation travels through the skin to reach the area being targeted for treatment. The skin in the treatment area may become red, dry, itchy or flaky. Most skin reactions occur within the first 2 weeks of receiving radiation treatment and usually go away a few weeks after treatment. Some skin changes, like darkening, can be permanent. Some people do not experience any skin reactions with radiation therapy for mesothelioma. The type of skin reactions that occur usually depend on the dose and length of radiation treatment.

Back to top


Fatigue is one of the most common side effects of radiation therapy for mesothelioma. Fatigue may be caused by anemia, poor appetite or depression. It may also be related to toxic substances that are produced when cancer cells break down and die. During radiation therapy, the body uses more energy to heal itself, so fatigue will not always be relieved by rest. Making frequent, daily trips for radiation treatments can also be tiring.

Radiation therapy to any area of the body can make a person feel more tired than usual, but fatigue is more common when larger areas of the body are treated. Anemia is more likely to occur when the treatment area includes bones where blood cells are formed in the bone marrow, such as the pelvic bones.

Fatigue usually occurs during or after the second week of radiation treatment. Symptoms of fatigue may increase or become more severe over the course of treatment. Fatigue usually goes away gradually after treatment has ended, but some people continue to feel tired for several weeks or months after radiation therapy.

Back to top

Nausea and vomiting

Radiation therapy to the lower chest or upper abdomen can cause an upset stomach and nausea and vomiting. People may start to feel nauseated about 1–3 hours after their daily treatment (about 1–2 weeks into therapy). The nausea tends to last, but is less intense as treatment progresses. Nausea and vomiting usually go away after treatment is finished.

Back to top

Loss of appetite

Loss of appetite is a common problem with mesothelioma and can lead to weight loss. Loss of appetite typically occurs after side effects like nausea and vomiting or fatigue (about 2–3 weeks into treatment) and when radiation therapy is given for peritoneal mesothelioma. It may continue for 2–3 weeks or longer after treatment has ended. Maintaining good nutrition during and after radiation therapy is important to help a person recover from treatment.

Back to top


Diarrhea is an increase in the number and looseness of stools. Radiation therapy to the abdomen to treat peritoneal mesothelioma can cause diarrhea. Diarrhea often begins 2–3 weeks into radiation therapy. Diarrhea usually goes away once radiation therapy treatments are completed.

Back to top

Lung problems

Radiation therapy to the chest to treat or relieve symptoms of pleural mesothelioma can cause lung damage. Lung problems can occur when the bronchi and lungs are in the treatment area and become irritated by radiation therapy. Lung damage leads to trouble breathing and shortness of breath. Lung problems sometimes start during radiation treatment, but usually occur a few months or more after treatment is completed.

Back to top


Dr Sean McKenna New treatments to outsmart cancer

Read more

Clinical trial discovery improves quality of life

Illustration of test tubes

A clinical trial led by the Society’s NCIC Clinical Trials group found that men with prostate cancer who are treated with intermittent courses of hormone therapy live as long as those receiving continuous therapy.

Learn more