Key takeaways
- Radiation therapy is the term for treatment types that use radiation to destroy or shrink cancer cells and tumors. The two main types of radiation therapy for treating cancer are external beam radiation and internal radiation therapy.
- The type of radiation that a doctor recommends will depend on the type of cancer, the size and location of the tumor, and the person’s general health.
- Side effects of radiation therapy include fatigue, appetite loss, and skin irritation. People can speak with their healthcare team to weigh up the risks and benefits of radiation therapy for them.
Radiation therapy may help meet different treatment goals. For instance, it may enhance the effectiveness of surgery, help prevent the spread of cancer, or relieve symptoms of advanced cancer.
This article discusses the different types of radiation therapy, including how they work, and the side effects. It also explains what a person can expect from radiation therapy and the likely outcome.
Radiation therapy is a type of cancer treatment that uses high energy beams to destroy cancer cells and shrink tumors.
The American Cancer Society (ACS) notes that
Radiation damages genetic material called DNA inside cancer cells. If the cancer cell cannot repair the DNA, the cell will not be able to produce new cells and may die. Radiation may damage noncancerous cells, but most can recover.
A person’s treatment team will carefully plan radiation therapy to minimize damage to noncancerous tissues and organs.
There are two broad types of radiation therapy that doctors use to treat cancers: internal and external.
External beam radiation
External beam radiation is a
External means that the energy beams come from a machine outside the body. A healthcare professional precisely aims the beams, which penetrate the body to reach the cancer site.
Another name for external beam radiation is teletherapy.
Internal radiation therapy
The second main type of radiation treatment is internal radiation therapy, also known as brachytherapy.
During this treatment, a doctor places an implant containing radiation in or near the cancer site. The implants come in different shapes, which
- tube
- wire
- capsule
- seeds
- pellets
Systemic radiation therapy
Systemic radiation therapy is another kind of internal radiation therapy.
It requires a person to swallow a radioactive substance, which travels throughout the body to find and kill the cancerous cells.
Alternatively, a healthcare professional may inject the radioactive substance into a person’s vein.
External beam radiation and brachytherapy work similarly. Both are local therapies that work on one part of the body, directing high energy beams at cancer cells to destroy them.
However, the two therapies
In brachytherapy, the radiation comes from an implant that a doctor places near or in a tumor. In external beam radiation, the radiation comes from a machine outside of the body.
A doctor may recommend radiation therapy for several purposes. These
- reducing or curing early stage cancer
- stopping cancer from spreading to another part of the body
- treating cancer that has returned
- relieving symptoms of advanced cancer
The
Brachytherapy may be an especially effective treatment for cancers in certain parts of the body, including the:
- breast cancer
- prostate cancer
- eye cancer
- cervical cancer
- cancers of the head or neck
External beam radiation therapy and brachytherapy both start with a meeting to plan the treatment.
A doctor will examine the individual, ask about their health, and discuss the therapy. In some cases, they may request imaging.
A person who decides to have external beam radiation will typically meet with a radiation oncologist and a radiation therapist for a planning session
The radiation therapist may put small marks on the person’s skin to show where to direct the energy beams.
In addition, healthcare professionals may create a body mold that they use to ensure that a person is in the correct position when receiving radiation therapy.
If a person is receiving radiation therapy to the head or neck, they may need to use a face mask to keep their head in place during treatment.
What to expect during radiation therapy will differ depending on which type of therapy a person receives.
External beam radiation
During an external beam radiation therapy session, a person will
The radiation therapist will position the individual in the machine and then go into a separate room.
Although the person must try to stay still during the treatment, they generally do not have to hold their breath. The machine will make whirring, clicking, and vacuum cleaner-like noises.
A speaker system in the room allows the person to talk with the radiation therapist during the treatment.
Internal radiation therapy
During brachytherapy, a person’s treatment team
Once the catheter or applicator is in position, the doctor will place the radiation source inside it.
In some cases, the implant may remain in the body for up to a few days before the doctor removes it.
In others, the doctor may place the implant in the body for a shorter period, such as 10 to 20 minutes, and repeat the treatment periodically for as long as several weeks.
Once the course of treatment is complete, the doctor will remove the catheter or applicator.
Sometimes an implant remains in the body permanently, but it will stop releasing radiation after some time.
When doctors use radiation therapy alongside other treatments, such as surgery or chemotherapy, they call it adjuvant treatment.
Some people might receive radiation therapy before surgery to shrink a tumor and make it easier to remove. Other individuals might receive it after surgery to destroy cancer cells that the surgery may have missed.
Sometimes, doctors use radiation therapy as part of palliative care to help relieve symptoms of advanced cancer. These may
The
- extreme fatigue
- loss of appetite
- skin irritation in the treated area
Other side effects may be specific to the body part that receives radiation. For example, radiation therapy affecting the head may lead to hair loss or changes.
People may be able to take the following steps at home to relieve radiation therapy side effects:
| Side effect | Tips to relieve it |
|---|---|
| fatigue | • place frequently used items within easy reach • relaxation methods, such as reading or deep breathing • ask others for help, if possible • rest or take short naps throughout the day • engage in gentle exercise every day • eat high protein foods, such as eggs, milk, beans, and meat • drink plenty of water • talk with a doctor if depression could be contributing to fatigue |
| skin irritation | • wear soft, loose-fitting clothing • avoid scrubbing or scratching the affected area • wash with lukewarm water and mild soap • protect the area from the sun • avoid hot or cold treatments, such as heating pads or ice packs • limit shaving or hair removal products on the treatment area • check with the healthcare team before using any cosmetics or topical remedies |
| appetite loss | • eat smaller meals more frequently • eat when hungry, even if it is not at a scheduled meal time • have company during meals or turn on the TV or radio • keep healthy snacks within easy reach • drink liquid supplements, if suitable • add calories to vegetables in the form of sauces or melted cheese • let others prepare meals, if possible |
Radiation treatment alone
It is important to note that a person cannot receive an unlimited amount of radiation. Therefore, doctors restrict the therapy to one part of the body and limit the total amount that a person receives over their lifetime.
Although radiation therapy itself generally does not cause pain, the treatment may cause painful side effects. A person should make their treatment team aware if they are in pain.
Undergoing radiation therapy
According to the ACS, radiation therapy may slightly increase a person’s risk of getting another cancer. A person should weigh the potential risks and benefits when deciding on a cancer treatment.
Radiation therapy is a common treatment for cancer. A person may receive radiation therapy alone or in combination with other treatments.
External beam radiation and internal radiation therapy, or brachytherapy, are the main types of radiation therapy.
An individual’s cancer type, tumor location, and treatment goals will help determine the best course of radiation treatment for them.