After a mesothelioma diagnosis, your doctor will discuss treatment options with you. One of those treatments may be mesothelioma radiation therapy.
You will probably hear a lot of medical terms that are confusing at first. To make informed decisions about your care, it’s important to understand the treatments and the terminology. In the explanation of mesothelioma radiation therapy that follows, you will learn some of the basics of this mesothelioma treatment and some of the medical language of mesothelioma treatment. The more you know about treatments such as mesothelioma radiation therapy, the more prepared you will be to make decisions about your care.
What is Mesothelioma Radiation Therapy?
Mesothelioma is a rare cancer that forms in the lining around an organ. This lining is called the mesothelium. Mesothelioma is caused by asbestos exposure. The most common form of the disease is pleural mesothelioma, which affects the lining inside the chest wall (the ribs) and around the lungs. Other mesothelioma types are peritoneal (the lining in the abdomen), pericardial (the lining around the heart), and testicular (the lining around the testicles).
Mesothelioma radiation therapy kills cancer cells. It is sometimes used to reduce tumors before or after surgery.
This treatment is also effective when combined with mesothelioma chemotherapy. Like chemotherapy, radiation can also be useful to treat tumors that can’t easily be removed by surgery.
Radiation is rarely used as a standalone treatment for mesothelioma.
Mesothelioma radiation therapy is not always recommended. If your tumor is too close to an important organ, radiation may be too dangerous. If your cancer is spread throughout your body rather than localized in one area, mesothelioma radiation treatment may not be effective.
If you don’t like the idea of receiving potentially high doses of radiation, it’s helpful to know a few basic facts about mesothelioma radiation therapy:
- It doesn’t hurt. While you may experience some local pain from the administration of the radiation, the radiation treatment itself is not painful.
- Radiation has fewer side effects than chemotherapy. Chemotherapy is very effective but it can also come with unpleasant side effects. The side effects of radiation tend to be much milder. You might not experience any nasty side effects at all!
- You won’t turn radioactive. The most common type of radiation therapy does not leave any radioactivity in your body. A treatment that involves radioactive implants may leave you very mildly radioactive for a short period of time, but it won’t have long-lasting effects.
Mesothelioma radiation therapies are highly targeted and can be a useful part of your cancer treatment plan.
How Does Mesothelioma Radiation Therapy Work?
In mesothelioma radiation therapy, a specialist called a radiation oncologist targets the tumor with ionizing radiation. Ionizing radiation is an energy beam strong enough to break electrons out of atoms. This process is called ionization.
In general, you should try to avoid exposure to ionizing radiation because it kills off cells or causes them to break down. This cell-killing power, however, is precisely why mesothelioma radiation therapy works. Using very narrow beams to avoid killing healthy cells, this treatment kills off cancerous cells. Radiation can reduce the size of a mesothelioma tumor and, in some cases, may be able to eliminate the entire tumor.
Types of Mesothelioma Radiation Therapy
There are three types of mesothelioma radiation therapy. The best type for you depends on the stage and type of your mesothelioma cancer.
External Beam Radiotherapy
The most common form of mesothelioma radiation therapy is external beam radiotherapy, also called EBRT. This type of radiation treatment is sometimes also called teletherapy. The first step in successful EBRT is to determine, as much as possible, the exact location and dimensions of your tumor. You may have x-rays or a CT scan to help your medical team plan your EBRT treatment.
This treatment aims beams of radiation at your tumor plus a small margin of healthy cells around it. Because the insides of our bodies move as we move, your tumor may shift slightly as you breathe or if your bladder is full. The extra margin makes sure the treatment gets to all your cancer cells, even if they have moved slightly.
If you’ve always wanted a tattoo, you’ll probably get one before your first EBRT session. It won’t be a heart or a rose, though – just a tiny dot to tell your radiation therapist where to aim the beam.
The therapist may also make a mold of part of your body before you start mesothelioma radiation therapy. When you lie down on the table for EBRT, you’ll have the mold under you. This specially molded shape that’s just for you helps you stay completely still while the radiation is administered. This is to help the treatment focus high-strength x-ray beams on the exact right spot.
Within EBRT, there are several different sub-types of radiation therapy.
- Three-dimensional conformal radiation therapy or 3D-CRT is a common technique used to reduce damage to noncancerous tissue during mesothelioma radiation treatment. The high-intensity beams of the EBRT must pass through some healthy tissue before reaching your tumor. 3D-CRT uses several beams of radiation that hit the cancer from different angles. Each beam alone is not powerful enough to kill the healthy cells they pass through. Your tumor is the focal point, where the beams meet. These beams of radiation work together to kill off mesothelioma cancer cells.
- Intensity modulated radiation therapy or IMRT uses different doses of radiation in different beams. This radiation treatment strategy applies more radiation to some parts of the tumor than others and reduces injury to normal cells.
- For helical-tomotherapy, you will lie on a table that moves in and out of a machine shaped like a donut (much like a CT scanner). This is a form of IMRT that delivers small beams of radiation from all around the donut, aimed at your tumor.
- Proton beam therapy is similar to radiation therapy, but it substitutes proton beams for the high-intensity x-rays used in mesothelioma radiation therapy. The difference between x-rays and protons is that proton therapy deposits much less radiation in the normal tissues that are not being targeted. Proton beam therapy may also be called hadron therapy. This treatment may have fewer side effects than radiation therapy, but it is still uncommon.
- Intraoperative radiation therapy or IORT is radiation administered during surgery, when the beam can be very precisely aimed at the exposed tumor with no intervening healthy tissue.
- Image-guided radiation therapy or IGRT uses medical imaging technology to more precisely target the radiation. Some radiation treatments involve particularly high radiation doses. These higher intensity radiation treatments require IGRT because it’s very important to target the large doses of radiation at the tumor and avoid healthy tissue.
EBRT treatments are given in cycles that can last from a couple of weeks to more than two months. A common mesothelioma radiation treatment schedule is daily therapy on weekdays. Your appointment will take half an hour to an hour, but you will only spend a few minutes of that time actually receiving radiation therapy. Be sure and wear loose clothing to your appointment and don’t wear deodorant or jewelry near the area to be treated.
The radiation passes through you, does its job killing cancer cells, then leaves. You will not be radioactive after your treatments, so you don’t need to worry that you will expose others to harmful radiation.
You may experience some side effects, including nausea, localized pain, and skin rash. Some side effects may depend on the location of your tumor. You may have difficulty breathing if mesothelioma radiation therapy affects your lungs. For peritoneal mesothelioma, this treatment may cause changes in your bowel or urinary function. Ask your doctor to explain all the possible side effects before your first treatment.
Brachytherapy is also known as sealed source radiotherapy or internal radiotherapy, because it involves inserting a sealed radiation source inside your body at the location of your cancerous tumor. In some cases, you may have both EBRT and brachytherapy. These mesothelioma radiation therapies can work well together.
At brachytherapy treatment, small radioactive capsules (or seeds, pellets, wires, balloons – brachytherapy inserts come in many different shapes) will be implanted in or near your tumor. The implantation will be done under an anesthetic.
The brachytherapy seeds can be implanted directly in the cancerous tissue or right next to it. This is interstitial brachytherapy. In some cases, the radioactive implants are inserted into a body cavity, such as the rectum. This is call intracavitary brachytherapy.
There are two types of implants: temporary and permanent. Temporary brachytherapy implants are placed and then removed. The temporary devices might be removed during the same appointment where they are put in place or they might remain in place for several days.
Permanent brachytherapy implants are left inside you. Like all radioactive materials, they become less radioactive over time and will eventually lose all their radioactive properties. Permanent implants usually only emit radiation for a few weeks.
Brachytherapy is also divided into high dose rate and low dose rate treatments. In high dose rate brachytherapy, the capsules are inserted by catheters. High dose radioactive capsules are usually only left in place for a few minutes at a time. Multiple doses are of this treatment is administered over a period of a week or two and then the catheters are removed.
If you receive low dose rate brachytherapy, you may stay over at a medical facility while the radioactive implants are in place. This treatment involves a lower dose of radiation that will attack your tumor for an extended period of time. Low dose rate brachytherapy implants stay in your body for a full day or more.
Which type of brachytherapy treatment you receive will depend on which mesothelioma type you have and the location of your tumor.
Brachytherapy has been shown to be effective and to have fewer side effects than external beam radiotherapy. You may experience some pain or swelling from the procedure to put the radioactive implants in place, but more general symptoms from the radiation are likely to be mild and short-lived. You may feel nausea or fatigue from the drugs you are given during the procedure and some patients feel hot and sweaty from the radiation.
Because you have radioactive implants inside your body during brachytherapy, you will be slightly radioactive for a while. This is one of the reasons you’ll be kept in the hospital during low dose rate brachytherapy. Your family won’t be able to stand close to you during treatment and you may need to avoid especially sensitive people (such as small children and pregnant women) at first.
Unsealed Source Radiotherapy
While unsealed source radiotherapy or unsealed source radionuclide therapy (RNT) is rarely used to treat mesothelioma, it’s a good idea to understand the basics about this third type of radiation therapy, in case your doctors mention it.
RNT is administered by injecting radioactive materials (radiopharmaceuticals) in such a way that they migrate to the site of the cancer. RNT substances may also be taken by mouth.
This type of radiation therapy is used mostly to treat a specific set of cancers, including bone cancer and thyroid cancer.
Radiologist vs. Radiation Oncologist
A radiologist is a medical professional who administers X-rays. You will work with a different type of radiation therapist when you receive mesothelioma radiation therapy.
Your medical team will probably include a radiation oncologist or a radiation therapist, or both. Radiation oncologists specialize in the uses of radiation to treat cancer. A radiation therapist is the technician trained to precisely administer treatments like EBRT.
Radiation as Part of Multimodal Mesothelioma Treatments
Surgery and chemotherapy are both useful mesothelioma treatments that have been shown to extend live expectancy. Multimodal treatments are even more effective. Studies find that patients who receive multiple types of treatment live more than twice as long as those who receive only one mesothelioma treatment.
Chemotherapy plus surgery is the most common multimodal mesothelioma treatment, but radiation can be an important component in a multimodal treatment plan. Radiation can kill cancer cells before or after surgery. Chemotherapy and radiation can also be a useful multimodal mesothelioma treatment if surgery is not an option.
Neoadjuvant and Adjuvant Mesothelioma Radiation Therapy
Mesothelioma radiation therapy may be used before or after other treatments. These two types of multimodal treatments are called neoadjuvant and adjuvant.
Neoadjuvant radiation treatments take place before other mesothelioma treatments, as preparation. A neoadjuvant use of mesothelioma radiation therapy would be to shrink a tumor before surgery. This neoadjuvant treatment allows the surgeon to remove the tumor more easily and completely.
Adjuvant therapy is also called adjunct or add-on treatment. When radiation is used as an adjuvant treatment, it may be administered after mesothelioma surgery to kill any stray cancer cells that the surgeon was not able to remove.
Radiation is also used as an adjuvant treatment in combination with mesothelioma chemotherapy. Mesothelioma radiation therapy increases the effectiveness of chemotherapy.