Understanding Radiation Therapy
What is radiation therapy?
How radiation treats your cancer
High-energy radiation is delivered to cancer cells or a tumor.
Radiation therapy works in two ways:
- Radiation can stop or slow the growth of the cancer.
- Radiation can shrink tumors, reduce some symptoms, and relieve pain.
Radiation therapy does not kill cancer cells right away. You may need several days or weeks of treatment with radiation before cancer cells start to die. Cancer cells will keep dying for weeks or months after radiation therapy is finished.
Radiation therapy starts with a plan
Your doctors will make a detailed radiation plan for your treatment. The plan includes:
- Where to aim the radiation beams.
- How much radiation you should get.
The goal of the plan is to provide the right amount of radiation to stop your tumor from growing or shrink it. The doctors want to protect you from any harm caused by the radiation, especially to the healthy cells around the tumor.
Different systems to deliver radiation
Doctors use different systems and tools to make the radiation therapy plan and deliver your radiation therapy. The approach your doctor may use to target the tumor, aim the radiation beams, and change the strength of the beams while they are being given has changed over time. Using different beam strengths may help protect you from the side effects of radiation.
What are the side effects of radiation therapy?
Everyone is different
Radiation therapy can cause damage to normal, healthy cells near and around your cancer. The damage may cause side effects. These side effects can be very different for different people. Your side effects may depend on the:
- Dose and type of radiation used.
- Site of your cancer.
- Stage of your cancer.
- Your age.
Types of side effects
Side effects can appear around 2 weeks after the first radiation treatment or much later and can include:
- Mouth sores (feels like little cuts or ulcers in your mouth).
- Dry mouth (also called “xerostomia” [pronounced zero-STOH-mee-ah]).
- Pain or difficulty with swallowing.
- Changes in taste or smell.
- Changes in the sound of your voice.
- Jaw stiffness and jaw bone decay.
- Changes in your skin.
- Feeling tired.
What impact can these side effects have?
Radiation therapy does not hurt when it is given. Some of the side effects can hurt or affect your quality of life, even when the radiation helps to stop or slow down your cancer. Some side effects last only a few days. Otherside effects can last weeks, months, or longer.
Some side effects, like dry mouth (xerostomia), may not ever get better. Your saliva, or spit, is used for many things. Saliva is needed as you eat to help you swallow your food. Saliva also helps to protect you from tooth decay, as well as tongue and gum disease, by keeping bacteria from settling on your teeth, tongue, and gums. Saliva even plays a role in speaking.