Radiation is used as a treatment during all 4 stages of mesothelioma. The primary purpose of radiation therapy is to shrink painful malignant tumors and keep them from growing. Radiation is often used in what’s called a “multimodal” approach along with surgery and chemotherapy.
Understanding Radiation for Mesothelioma
The main goal of radiation therapy for mesothelioma is to relieve pain, but radiation can also kill cancer cells. It may also increase life expectancy, especially when combined with other treatments.
Radiation works by damaging the DNA inside mesothelioma cells. Damaging DNA within these cancer cells prevents them from replicating and spreading. Radiation isn’t painful and it can reduce symptoms of mesothelioma.
People with pleural mesothelioma often have chest pain from the tumor invading the chest wall. Radiation treatments can shrink these tumors, which frees up space and alleviates pain. A radiologist will likely give you external ionizing radiation directly to the area of the tumor.
Uses of Radiation Therapy in Mesothelioma
There are several ways doctors use radiation in mesothelioma patients.
These methods include:
- Adjuvant Therapy. Doctors prescribe radiation after the patient has surgery. In an extrapleural pneumonectomy, the cancer-affected lung is removed. A doctor directs radiation at the area where the cancer used to be. Doctors avoid radiation exposure to the healthy lung. Research has shown that radiation after surgery may double your survival time.
- Neoadjuvant Therapy. Doctors also give radiation before surgery. The purpose of this is to reduce the size of tumors, which can make surgery more successful.
- Palliative Relief of Pain. Radiation has the capacity to relieve cancer pain. It’s often used this way in patients whose cancer has spread to the lymph nodes or to the chest wall itself. About half of all people will have a decrease in these symptoms after receiving radiation treatments. Relieved symptoms include shortness of breath and pain. Patients can get radiation any time after surgery if pain arises from tumor recurrence.
- Prevention of Seeding. Mesothelioma spreads along surgical incisions and biopsy sites. This is called seeding. Up to half of all patients have seeding after a surgical procedure. There is some evidence that directing radiation at these areas decreases seeding, though this treatment is controversial as research is inconclusive. If seeding does occur, radiation can decrease the pain of cancerous nodules.
Types of Radiation
There are two main types of radiation therapy used in the management of pleural mesothelioma. These include the external beam radiation and brachytherapy.
In this procedure, radiologists use a machine that generates radiation and can be directed at any site where there are tumors. Radiologists mark the areas to apply radiation to ensure each dose of radiation goes to the same site every time. Radiation therapy is usually given 5 times a week for several weeks in a row. Visits take about an hour.
There are two types of external-beam radiation. They are:
- 3D-CRT. The first type is three-dimensional conformal radiation therapy. Here, 3-dimensional images are taken of the tumor and a uniform intensity of radiation is delivered.
- IMRT. There is also intensity-modulated radiation therapy. Here, different intensities of radiation are delivered in the specified area. This means more radiation goes to the tumor site. It also means less radiation reaches the surrounding area.
External-beam radiation is done on an outpatient basis, and is often done more than once. It generally isn’t painful to have this type of treatment, though it may irritate the skin and cause minor burns.
This is the least used type of radiation for management of pleural mesothelioma.
Brachytherapy involves making an object (such as beads) radioactive. A surgeon inserts the radioactive substance directly where the tumors are. The radiation acts on the tissues in which it is embedded. This helps kill off mesothelioma cells that weren’t removed during surgery.
Brachytherapy has the advantage of not causing radiation exposure to healthy tissue; it only affects the immediate surrounding area.
Brachytherapy can be permanent or temporary. The beads are generally radioactive for several months. A surgeon may remove the beads after their radiation wears off. Or your doctor will leave the newly harmless beads in place. Most doctors choose to leave the beads in as they rarely cause pain.
A doctor can put the beads in at the time of surgery or they can insert the beads using a large needle. With needle insertion, doctors use imaging techniques to properly direct the beads to the tumor site.
Some doctors prefer to use high dose surface brachytherapy. In this procedure, the radioactive object isn’t used inside the body but is instead placed upon the skin at the incision site. This can prevent seeding of tumor into the incision itself. This type of brachytherapy is easy to remove.
Getting Radiation Treatments
When you receive radiation, the first step is to define the area to be irradiated. This is usually done by having an MRI or CT scan. Doctors may prescribe medications after radiation therapy. Some medications increase radiation effectiveness. Others prevent damage to the normal cells in the radiated area.
When the radiation is underway, you can develop skin burns, blistering or moderate fatigue. Years later patients can have scar tissue in the lung. There can also be destruction or calcification of local lymph nodes.
Potential side effects of radiation treatments include:
- Radiation pneumonitis
- Radiation myelitis
- Hair loss
- Skin burns
Not everyone will have adverse reactions to radiation therapy. It can be very helpful in controlling the symptoms of mesothelioma.
Innovations in Mesothelioma Radiotherapy
Mesothelioma specialists are always looking for ways to improve treatments for mesothelioma. This even includes radiation therapy.
Here are some new ways doctors are using radiation in mesothelioma patients:
- Intensity Modulated Radiation Therapy (IMRT). This type of radiation uses targeted beams to attack mesothelioma tumors. The American Cancer Society explains that IMRT “shapes the radiation beams to fit the tumor and aims them at the tumor from several angles, as well as adjusting the intensity (strength) of the beams to limit the dose reaching nearby normal tissues.” Targeted radiation protects healthy cells from damage, which reduces the side effects of radiation. IMRT is even used after pleurectomy with decortication to kill any remaining cancer cells.
- Surgery for Mesothelioma After Radiation Therapy (SMART). This is an experimental therapy similar to neoadjuvant radiation therapy. Doctors apply a large dose of radiation to the affected lung before surgery. The amount of radiation is so high that surgery has to happen to prevent radiation toxicity. A few days after radiation treatment, doctors perform an extrapleural pneumonectomy. Late stage patients who received this treatment have had survival times of more than 3 years.
In 2014, doctors published results of a study using IMRT in pleural mesothelioma surgery. The median survival for patients who had IMRT after extrapleural pneumonectomy was over 28 months. That’s just over 2 years.
Getting Radiation Therapy
Radiation is one of the most common treatments for all types of cancer. It’s used for all stages and types of mesothelioma. Radiation can help reduce symptoms and shrink tumors before surgery. Doctors are inventing more effective ways to deliver radiation, such as IMRT.
Things to consider about radiation:
- Radiation is often used with other treatments.
- It can be used before or after surgery.
- Radiation can reduce mesothelioma symptoms and shrink tumors.
If you’ve been diagnosed with mesothelioma, you’ll probably get radiation at some point. Your doctor can answer any questions you have about radiation. If you’re a veteran, learn more about mesothelioma treatment in the VA health care system.