Radiation therapy is a cancer treatment that uses concentrated radiation beams to kill cancer cells.
The most common type of radiation therapy is external beam radiation. This type involves a machine that directs high-energy beams of radiation at cancer cells. The machine allows radiation to be targeted at specific sites, which is why doctors use external beam radiation for nearly all types of cancer.
According to the Mayo Clinic, about half of all cancer patients will receive radiation therapy ().
Radiation therapy is an important tool for treating cancer, and is often used in conjunction with other therapies, such as chemotherapy or tumor-removal surgery.
The main goals of radiation therapy are to shrink tumors and kill cancer cells. While the therapy also will likely injure healthy cells, the damage isn’t permanent. Your normal, noncancerous cells have the ability to recover from radiation therapy. To minimize the effect radiation has on the body, the radiation is targeted only to a specific point(s) in your body.
Radiation therapy can be used during different stages of cancer treatment and for different outcomes. Radiation therapy can be used:
- to alleviate symptoms in advanced, late-stage cancer
- as the primary treatment for cancer
- in conjunction with other cancer treatments
- to shrink a tumor before surgery
- to kill any remaining cancer cells after surgery
No matter what type of radiation is used, hair loss (which only happens on the part of your body being treated) and fatigue are common side effects. Radiation also affects skin cells. Skin changes can include blistering, dryness, itching, and peeling.
Other side effects of radiation depend on the area being treated, and can include:
- mouth sores
- dry mouth
- sexual dysfunction
- sore throat
- trouble swallowing
- urination difficulties
According to the National Cancer Institute, most of these side effects go away two months after treatment is complete. In rare cases, side effects can linger or even appear six or more months after treatment has finished. Late side effects can include mouth problems, joint problems, lymphedema (tissue swelling), infertility, and/or possible secondary cancer (). Talk to your doctor about any concerns you have regarding side effects.
The first step in radiation treatment is determining that it is the right form of treatment for you. Your doctor will also determine dosage amounts and the frequency of radiation best suited for your cancer type and stage. Sometimes your doctor may decide that radiation therapy is best suited for use at a later stage, so you may receive other cancer treatments first.
Preparation for radiation therapy involves a radiation simulation, which typically includes the following steps:
- You will lie on the same type of table that will be used for your treatment.
- Lying still at the proper angle is very important for treatment success, so your healthcare team may use cushions and restraints to position you at the best angle for treatment.
- You will then undergo computed tomography (CT) scans and/or X-rays to determine the full extent of your cancer and where the radiation should be focused.
- After determining the best location for radiation treatment, your treatment team will then make the area with a very small tattoo (usually the size of a freckle). In certain cases, a permanent tattoo is not needed.
- You are now ready to begin radiation therapy.
Radiation therapy typically takes treatment sessions five days a week for one to 10 weeks. The total number of treatments depends on the size and type of cancer. Each session usually takes about 10 to 30 minutes. Often, the individual is given each weekend off from therapy, which helps with the restoration of normal cells ().
At each session, you will lie on the treatment table, and your team will position you and apply the same types of cushions and restraints used during your initial radiation simulation. Protective covering or shields may also be positioned on or around you to protect other body parts from unnecessary radiation.
Radiation therapy involves the use of a linear accelerator machine, which directs radiation at the appropriate spot. The machine may move around the table in order to direct the radiation at the appropriate angles. The machine may also make a buzzing sound, which is perfectly normal.
You should feel no pain during this test. You will also be able to communicate with your team via the room’s intercom, if necessary. Your doctors will be nearby in an adjacent room, monitoring the test.
During the weeks of treatment, your healthcare provider will closely monitor your treatment schedule, dosing, and your general health.
You will undergo several imaging scans and tests during radiation so your doctors can observe how well you are responding to treatment. These scans and tests can also tell them if any changes need to be made to your treatment.
If you experience side effects from radiation—even if they are expected—tell your healthcare provider at your next appointment. Sometimes, even small changes can make a big difference in lessening side effects. At the very least, you may be given advice or a medication to help ease the discomfort.