Mesothelioma, from the CureRays guide library.

Mesothelioma is an uncommon cancer of the lining around the lungs or abdomen, usually linked to past asbestos exposure; a coordinated team using surgery, chemotherapy, immunotherapy, and radiation can meaningfully control it.

What it is.

Mesothelioma is an uncommon cancer that begins in the mesothelium — the thin protective lining that wraps around the lungs, the abdominal organs, and the heart. By far the most common form starts in the lining around the lungs (the pleura) and is called pleural mesothelioma; a less common form arises in the lining of the abdomen (the peritoneum). Its defining feature is its strong link to asbestos: most cases trace back to breathing in asbestos fibers years or even decades earlier, often at work, which is why it tends to appear later in life and why occupational history is an important clue. Because mesothelioma grows as a sheet along a lining rather than as a single ball-shaped tumor, it can be challenging to treat, and care is highly team-based. Modern treatment combining surgery, chemotherapy, immunotherapy, and radiation — along with excellent symptom support — can meaningfully control the disease and improve both length and quality of life.

How radiation treats it.

Radiation uses focused high-energy x-rays to damage the DNA of cancer cells so they can no longer grow and divide. Mesothelioma poses a special challenge because it spreads as a thin sheet along a curved lining wrapped around the lung, rather than as a compact ball, so the radiation target is large and irregular and sits right next to the lung, heart, and other sensitive organs. This is where modern, image-guided and intensity-modulated radiation has made an important difference: the team can shape the dose to follow the lining while sparing healthy tissue beneath. Radiation is used to relieve symptoms such as pain or breathlessness, to lower the chance of regrowth after surgery, and in selected patients to treat the chest lining more definitively. It is often combined with chemotherapy, immunotherapy, and surgery as part of a coordinated plan. Treatments are painless and given over a number of sessions, with side effects — usually temporary fatigue, mild skin irritation, or swallowing discomfort — depending on the area treated.

The ways we can treat it.

Palliative radiation. Focused radiation relieves pain, breathlessness, or other symptoms from a specific area of disease, improving comfort — one of radiation's most valuable roles in mesothelioma.

Post-operative radiation. After surgery to remove the tumor-bearing lining, carefully targeted radiation to the chest lowers the chance of regrowth, using advanced planning to protect the remaining lung, heart, and other organs.

Advanced, lung-sparing techniques. Intensity-modulated radiation and image guidance shape the dose to the complex, sheet-like target along the chest wall while sparing the underlying lung, making safer treatment possible in selected patients.

Questions we hear often.

Is mesothelioma always caused by asbestos? Most cases are linked to breathing in asbestos fibers, often years or decades earlier and frequently at work — which is why it usually appears later in life and why your asbestos history is an important part of the evaluation. A minority of cases occur without known asbestos exposure. Either way, treatment is the same.

Why does mesothelioma seem harder to treat than other cancers? It grows as a thin sheet spreading along the lining around the lung rather than as a single lump, so it's harder to remove completely or target. But treatment has improved markedly — immunotherapy, chemotherapy, carefully selected surgery, and modern radiation, combined by an expert team, can meaningfully control the disease and improve quality of life.

What can radiation do for me? Radiation has several roles: it's very effective at relieving symptoms like pain and breathlessness from a specific area, it can lower the chance of regrowth after surgery, and in selected patients modern lung-sparing techniques allow more definitive treatment of the chest lining. Your team will explain how it fits into your overall plan.

This guide is informational only. It is not medical advice — please confirm anything here with your care team.