Radiation therapy | Its types, uses, and risk factors

Radiation therapy is an effective treatment for a wide variety of cancers. It is also possible to combine it with other cancer treatments, such as chemotherapy or surgery, in order to achieve better results.

Radiation therapy is a way to treat cancer by killing cancer cells with high-energy x-rays or other particles. Most of the time, X-rays are used in radiation therapy, but protons or other types of energy can also be used.

Most of the time, when people talk about "radiation therapy," they mean "external beam radiation therapy." During this type of radiation, high-energy beams come from a machine outside of your body that points the beams at a specific spot on your body. Radiation is put inside your body during brachytherapy, which is a different kind of radiation treatment.

Types of Radiation therapy?

Radiation therapy comes in two main forms: external beam and internal.

What kind of radiation therapy you get depends on many things, such as:

how bad the cancer is
the size of the tumour, where it is in the body, and how close it is to normal, radiation-sensitive tissues.
your health in general and your medical history
if you will get other kinds of cancer treatment.
other things, like your age and other health problems

External radiation therapy

A machine sends radiation to your cancer as part of external beam radiation therapy. The machine is big and might make a lot of noise. It doesn't touch you, but it can move around you and send radiation to different parts of your body from different directions.

External beam radiation therapy is a local treatment, which means it only affects one part of your body. For example, if you have lung cancer, radiation will only be given to your chest and not to your whole body.

Internal radiation therapy

In a treatment called internal radiation therapy, a source of radiation is put inside your body. The source of the radiation can be a solid or a liquid.

The use of a solid source for radiation therapy inside the body is called brachytherapy. In this kind of treatment, seeds, ribbons, or capsules with a source of radiation are put in or near the tumour. Like external beam radiation therapy, brachytherapy is a local treatment that only affects one part of your body.

With brachytherapy, the source of radiation is put inside your body, where it stays for a while. Systemic therapy is radiation therapy done inside the body with a liquid source. When treatment is systemic, it means that it travels through your blood to tissues all over your body to find and kill cancer cells. Systemic radiation therapy can be taken by mouth, through a vein with an IV line, or by getting an injection.

Why is radiation therapy done?

Radiation therapy is used to treat cancer in more than half of all cancer patients. Radiation therapy is used to treat almost every kind of cancer. Some tumours that are not cancerous can also be treated with radiation therapy. Radiation therapy kills cancer cells, makes tumours smaller, and eases the pain and other symptoms of cancer.

How do people with cancer use radiation therapy?

At different times and for different reasons, your doctor may suggest radiation therapy as one of the ways to treat your cancer.

As the main (only) way to treat cancer
Before surgery, a cancerous tumour needs to be shrunk down (neoadjuvant therapy)
To stop the growth of any cancer cells left over after surgery (adjuvant therapy)
Together with other treatments, like chemotherapy, to kill cancer cells
In advanced cancer, to relieve symptoms that the cancer is causing,

What are the possible side effects or risks of this treatment?

Radiation therapy is a good way to treat many types of cancer, but it may also make you more likely to get another cancer in the future. Radiation therapy has benefits that are worth the risk for many people.

Talk to your radiation oncologist about the pros and cons of the treatment.

What happens before the treatment of radiation?

You may need a physical exam and imaging for internal radiation therapy. Depending on how you'll get the radiation, your radiation oncologist will tell you how to get ready for the day of the procedure.

In order to plan for external beam radiation therapy (EBRT), a planning appointment called a simulation is needed. Simulation is the step in planning the treatment that lets you make it fit your needs.

This is what simulation is:

Getting into place. You're on a table, just like you'll be during your treatment sessions. The people giving you radiation therapy may use a mould or mask to keep your body in place. They'll make sure you're lined up right. You may get tiny dots that show which parts of your body should get the radiation. These dots may be temporary or permanent.

Having scans done. You'll get a CT scan or an MRI, which will show where the tumour is. With this information, your care team will be able to tailor X-rays so that they focus on the tumour and avoid healthy tissue.

Your radiation oncologist can use simulation to figure out how much radiation you'll get and how you'll get it.

What happens when a patient gets radiation therapy?

Internal radiation therapy is usually done in a hospital or a special room for outpatients. Your radiation oncologist may use a small, flexible tube called a catheter to put in the radiation implant. You will be given anaesthesia for this treatment so that you don't feel any pain or discomfort during the procedure. For systemic internal radiation therapy, radioactive fluid will be given to you through an IV.

For EBRT, you lie on a table in the same way you would for a simulation. The machine that sends out radiation moves around you, but it never touches you. From a separate room, a person called a radiation therapist runs the machine. An intercom lets you talk to each other at any time. As the machine changes positions, it sends precise amounts of radiation to the tumour. During treatment, you won't feel anything.

What happens after radiation therapy?

When you get radiation therapy inside your body, you'll usually be able to go home the same day after a short recovery. You might need to stay in the hospital while your body gets rid of small amounts of radiation. After systemic (IV) radiation therapy, your sweat, urine, and blood could have small amounts of radiation in them.

If you get radiation therapy through an IV or a permanent implant, there is a small chance that you could spread radiation to other people. Follow the advice of the people who gave you radiation therapy about how many contacts you should have with other people.

Before and after EBRT, you should be able to do the things you do every day. There's no chance of giving radiation to other people.

FAQs

When should I see the person who takes care of my radiation?

Ans: Your radiation care provider should know about any side effects you're having, especially those that make your life harder. Depending on how you respond to treatment, your doctor may need to change your dose, change how often you get treatment, or try a different type of treatment.

What are the risks of radiation therapy?

Ans: Most people have more than one session of radiation therapy, so they don't get the full dose all at once. Between treatments, the schedule gives your healthy tissue time to heal. The time it takes to heal lessens the side effects.

Still, you might have some bad side effects that your radiation oncologist can help you deal with. Most of the time, these side effects only happen in the part of your body that is directly exposed to radiation.

Some possible side effects are

Fatigue
Nausea
Vomiting
Diarrhoea
Headaches
Damage to the skin
Uneasyness

When will I be able to go back to my normal schedule?

Ans: Some people who are getting radiation can still do their normal things. Some people are so sick that they need to stop and rest. Many people don't have side effects until after the treatment has been going on for a few weeks and more cells have died.

Talk to your radiation care provider about the best and worst things that could happen as you plan your schedule around treatment.