External Beam Radiation Therapy

Radiation therapy, or radiotherapy, is one of the three main types of treatment traditionally used to treat mesothelioma. It is often used in combination with chemotherapy, surgery, or both, to maximize the effectiveness of all treatments. Radiation is made up of high energy particles capable of killing cancer cells. External beam radiation is the most common way to deliver this treatment. It involves aiming a beam of radiation at the tumor from outside the body. There are potential risks associated with this, but advances in research have made the technique more focused and safer.

Types of Radiation Therapy

Radiation therapy works by targeting tumor with high-energy radiation. This high-energy beam kills all types of living cells, both cancerous and healthy, but healthy cells rebound better. Even so, radiation can kill and destroy healthy cells, cause cancer in healthy cells and cause a number of side effects by damaging healthy tissue. Focusing the radiation on cancer cells is an important part of this therapy.

External beam radiation is one main type of radiation therapy. It refers to the use of external radiation, aimed at the part of the body that contains the tumor, to kill cancer cells. A machine, usually a linear accelerator, produces X-rays or another type of high-energy radiation, focuses it into a beam, and aims it at the right spot on a cancer patient’s body.

The other type of radiation therapy is called brachytherapy and it involves placing a device inside the body that emits radiation. This small device is usually placed next to a tumor and may be put in permanently, or may be removed after a period of time. The radiation travels only a short distance and is focused on the tumor.

Types of External Beam Radiation Therapy

External radiation can further be subdivided into more specific types. Most of these are the result of recent advances in delivering external radiation more accurately and safely. Three-dimensional conformal radiation therapy involves using imaging scans to create a three-dimensional model of a tumor before treatment. This allows the medical team to use a computer to conform the delivery of the radiation to the shape of the tumor, which results in less radiation to healthy tissue. This can be made even more precise by modulating the intensity of the radiation.

Another type of external beam radiation uses a beam of protons, instead of the photons that are used with traditional radiation. This causes less damage to healthy tissue. Intraoperative radiation is radiation that is dosed to a patient during surgery. Electromagnetic-guided radiation uses the implantation of small transponders to guide radiation to the tumor.

How External Radiation Therapy Is Used for Mesothelioma

External radiation therapy is the most common type used to treat cancers, including mesothelioma. There are two main purposes when using this treatment for malignant mesothelioma: after surgery and for palliative care. After surgery, radiation is used to destroy any remaining cancer cells. Surgery is one of the most effective ways to eliminate mesothelioma tumors, but a surgeon cannot get every single cell out, especially those that cannot be easily seen. Using radiation after surgery, can effectively “clean up” the area and kill remaining cells. This has been shown to extend life expectancy in patients who underwent an extrapleural pneumonectomy.

As palliative care radiation has an important part to play for mesothelioma patients. When treating the cancer with the hope of remission or life extension is no longer possible, palliative treatments are used to help make the patient more comfortable. External beam radiation can shrink tumors to make breathing easier, to relieve pain, and to reduce swelling.

What to Expect

If you will be undergoing external beam radiation therapy to treat your mesothelioma, you can expect to go through several steps. The first is likely to be getting a checkup and examination from the radiation oncologist. Then you will probably need to undergo imaging scans, such as CT scans or MRIs, depending on the type of therapy your doctor will be using.

You may need to have ink placed on your skin to help technicians aim the radiation beam correctly. You may also be fitted to body molds to help you stay in the correct position during the treatment and to help guide the radiation beam. During the actual treatment you will be guided to the correct position, either lying down or sitting and probably with molds to help you stay in position easily. The technician or doctor operating the machine will leave the room and watch from a monitor or window as the beam of radiation is started. You will have to remain still, but it will not hurt and will only take about 15 to 30 minutes. You may go through several such sessions on different days.

Side Effects of External Beam Radiation

Radiation therapy may cause side effects, mostly temporary. The more guided types of radiation, such as three-dimensional and intensity-modulated radiation, minimize damage to healthy tissues, which helps to reduce side effects. Acute side effects that you may experience during and shortly after treatment include irritation, burning, and hair loss to the skin at the site of the radiation.

Commonly, patients undergoing radiation for any type of cancer will experience fatigue. Therapy to the chest area, as when treating pleural mesothelioma, can cause inflammation of the lungs. This can cause difficulty breathing, coughing, and other symptoms that may last several months and in some cases may be permanent. For peritoneal mesothelioma, radiation to the abdomen can result in harm to the bowels and bladder, which may lead to digestive issues or incontinence. Rarely, radiation therapy may cause a secondary cancer.

External beam radiation is an important part of a multimodal approach to treating mesothelioma. It can cause side effects, and possibly lasting damage to healthy tissue, but more advanced strategies for using external radiation, these risks are lowered. For someone with mesothelioma, radiation may be crucial in extending life after surgery or in making life more comfortable living with this cancer.