What happens during radiation therapy
The most common way to get radiation for a thymus tumor is from a machine outside your body. This machine sends out an invisible beam of energy. This is called external radiation. Sometimes special types of external radiation are used to try to limit the doses of radiation reaching nearby normal cells. This includes intensity-modulated radiation therapy (IMRT) and 3-D conformal radiation therapy (3D-CRT).
A doctor who specializes in cancer and radiation is called a radiation oncologist. This doctor works with you to decide the kind of radiation you need. This doctor also figures out the dose and how long you need treatment.
Most people get external radiation on an outpatient basis in a hospital or clinic. This means you go home after each treatment. Most people get radiation 5 days a week for many weeks.
Getting ready for radiation
Before your first radiation treatment, you’ll have a session to figure out exactly where on your body the radiation beam needs to be directed. The process is called simulation. It may take up to 2 hours. During this session, you may have imaging tests, such as CT scans or MRI scans. These can help your healthcare providers know exactly where the tumor is to better aim the radiation. Also at this session, you may have body molds made to help put you in the same position and keep you from moving during each treatment.
Then, you’ll lie still on a table while a radiation therapist uses a machine to define your treatment field. The field is the exact area on your body where the radiation will be aimed. Sometimes it’s called your port. The therapist may mark your skin with tiny dots of semi-permanent ink or tattoos. This is done so the radiation will be aimed at the exact same place each time.
On the days you get radiation
On the days you get radiation treatment, you’ll lie on a table while the machine is placed over you. You may have to wear a hospital gown. It’s a lot like getting an X-ray, only longer. It takes about 15 to 30 minutes to complete. But you should plan on being there for about an hour.
At the start of the treatment session, a radiation therapist may use blocks or special shields to protect parts of your body that don’t need to be exposed to radiation. The therapist then sets up the machine so that lights from the machine line up with the marks on your skin that were made during simulation. When you’re ready, the therapist leaves the room and turns the machine on. You may hear whirring or clicking noises, a lot like the sounds of a vacuum cleaner, while the radiation is being given. During the session, you’ll be able to talk to and hear the therapist over an intercom. The therapist can see you the whole time. The machine won't touch you and you can’t feel radiation, so the process won't hurt. Also, you won’t be radioactive afterward.
What to expect after radiation therapy
Because radiation affects normal cells as well as cancer cells, you may have some side effects. The side effects from radiation are usually limited to the area being treated. Some people have few or no side effects. But if you have them, your healthcare provider may change the dose of radiation or how often you get treatments. Or your healthcare provider may stop treatment until the side effects clear up. Be sure to tell your healthcare provider about any side effects you have.
Possible short-term side effects
These are some of the common short-term side effects:
Skin irritation or changes where the radiation goes into your body. This can be like a bad sunburn. Your skin may blister and peel.
Irritation of your esophagus. This could lead to eating problems such as pain when swallowing.
Loss of appetite and weight loss
If you have any side effects, ask your healthcare provider or nurse how to best deal with them. Also ask how to know when they become serious. Most side effects can be treated, and some can even be prevented. Side effects normally go away over time after you stop getting treatment.
Potential long-term side effects
Radiation can cause some long-term side effects. These depend on where the radiation was aimed. This is a special concern when treating tumors in young adults. Long-term side effects can include:
Lung damage. Radiation might harm your lungs. This could lead to trouble breathing and shortness of breath.
Increased risk of heart disease. This includes heart attacks.
Second cancers. Cancers are more likely to form in areas that have received radiation. These cancers may form even decades after treatment.