Radiation therapy uses high-energy x-rays or particles to kill cancer cells. Mesotheliomas are usually hard to treat with radiation therapy. They are not usually contained as single, discrete tumors, and aiming radiation at them while sparing nearby normal tissues has proven difficult. But new radiation therapy techniques may make this form of treatment more useful.

Uses of radiation therapy

Radiation therapy may be used in different ways to treat mesothelioma:

• It can be used as the main treatment of mesothelioma in some patients, especially those whose general health is too poor to have surgery.

• It can be used after surgery (adjuvant radiation therapy) to try to kill any small deposits of cancer that could not be seen and removed during surgery.

• Radiation therapy can be used to ease (palliate) symptoms of mesothelioma such as shortness of breath, pain, bleeding, and trouble swallowing.

Types of radiation therapy

There are 2 main types of radiation therapy that can be used to treat mesothelioma:

External beam radiation therapy (EBRT): This type of radiation therapy uses x-rays from a machine outside the patient's body to kill cancer cells. It is the most common form of radiation therapy for mesothelioma. The treatment is much like getting an x-ray, but the radiation is more intense. The procedure itself is painless. Before your treatments start, the medical team will take careful measurements to determine the correct angles for aiming the radiation beams and the proper dose of radiation. Each treatment lasts only a few minutes, although the setup time -- getting you into place for treatment -- usually takes longer. Most often, radiation treatments are given 5 days a week for several weeks.

With newer techniques, doctors can more accurately treat mesotheliomas while reducing the radiation exposure to nearby healthy tissues such as the lungs. This may offer a better chance of increasing the success rate and reducing side effects.

For example, intensity-modulated radiation therapy (IMRT) is an advanced form of 3-dimensional radiation therapy. It uses a computer-driven machine that moves around the patient as it delivers radiation. Along with shaping the radiation beams and aiming them at the tumor from several angles, the intensity (strength) of the beams can be adjusted to minimize the dose reaching the most sensitive normal tissues. Many major hospitals and cancer centers are now able to provide IMRT.

Brachytherapy: In this type of radiation therapy, the doctor places radioactive material directly into the chest or the abdomen at the site of the mesothelioma. The radiation given off travels only a very short distance, which limits the potential damage to nearby healthy tissues. Brachytherapy is seldom used for this type of cancer.

Possible side effects

Side effects of radiation therapy may include fatigue and mild skin changes that resemble sunburn. These usually go away once treatment is finished. Chest radiation therapy may cause lung damage and lead to trouble breathing and shortness of breath. Abdominal radiation therapy may cause nausea, vomiting, and diarrhea.

If radiation therapy is used together with chemotherapy, it may make the side effects of chemotherapy worse.

If you are having any side effects from radiation therapy, talk with your doctor. In most cases there are ways to help control these symptoms.

For more general information about radiation therapy, please see our document, Understanding Radiation Therapy: A Guide for Patients and Families.

Last Medical Review: 03/17/2009
Last Revised: 03/17/2009