Radiation therapy on its own is generally not effective because of the location of malignant mesothelioma. It is extremely difficult to deliver sufficiently high doses of radiation to kill the tumor on the mesothelium without damaging the surrounding organs.
Although radiation therapy after surgery has not been shown to improve survival, lower doses of radiation can result in some reduction in the disease, but it is unclear whether this reduction actually results in longer survival than no treatment. That is why radiation therapy is often used after surgery has been performed.
Radiation therapy, in these cases, is meant to kill any remaining tumor cells that may be remaining after surgery. In addition, radiation therapy can be used to relieve symptoms of mesothelioma, including chest pain.Courtesy of Ringsurf.com