Radiation Therapy

Radiation therapy uses high-energy beams of particles to eliminate cancerous cells. Mesothelioma cancer can be hard to treat with radiation therapy because the cancer is not typically a single tumor. However, radiation therapy has evolved into a more precise delivery system, leading to improved outcomes for patients.
After a patient has undergone surgery, they may receive adjuvant radiation therapy, which attempts to remove the remaining cancerous tissue. Radiation therapy can also be used to help relieve the symptoms of mesothelioma including bleeding, pain, trouble breathing, shortness of breath or difficulty swallowing.

External Beam Radiation

While there are two types of radiation therapy used to kill cancer cells, external beam radiation is the more common method. Doctors use a machine to emit a beam of radiation to the exact location of the body where the cancer exists and the process is performed much like an x-ray. Because the machine does not physically touch the patient, the procedure is considered painless and typically performed as an outpatient procedure.
Even though the radiation kills off the cancer cells, the powerful radiation can sometimes kill off healthy cancer cells, leading to unpleasant side effects. Depending on what type of cancer the patient has and where it is located in the body, the length of treatment will vary. External beam radiation therapy treatments are typically given for five 30-minute treatments each week from one to several weeks.
Newer technology such as intensity-modulated radiation therapy is aimed at lessening the radiation effects on healthy cells. This three-dimensional therapy utilizes a machine powered by computers that moves slowly around the patient while simultaneously emitting the radiation. The machine can also shape the beams and strike the tumor from various angles; the intensity of the radiation can also be adjusted so that non-cancerous cells remain unaffected.

Brachytherapy

A relatively new type of radiation therapy used to treat mesothelioma cancer is brachytherapy in which the radiation is emitted directly into the cancerous tumor. Brachytherapy is more exact than external beam radiation, so fewer healthy cells are destroyed in the process.
The patient is administered a general anesthesia and catheters are used to implant seeds or rods near the tumor location. The seeds or rods can either stay in temporarily or permanently. The implants will emit radiation for three to twelve months. Brachytherapy is also administered at outpatient facilities.

Side Effects

External beam radiation therapy can cause severe fatigue and skin conditions similar to sunburn such as redness or drying. Hair loss is also a common side effect that occurs where the radiation enters the body. Once the treatment is finished, these side effects dissipate. If chest radiation therapy is administered, side effects may include shortness of breath or trouble breathing, as well as possible lung damage. Abdominal radiation therapy may cause a loss of appetite, nausea, vomiting or diarrhea. While radiation therapy has fewer side effects than chemotherapy, if the two treatments are used simultaneously, the side effects may increase.
Reference:
American Cancer Society
National Cancer Institute