Radiation Therapy Side Effects

• Stereotactic radiosurgery (radiation given in one large dose): This is often part of treatment for brain tumors that are only in a few sites of the brain. Side effects depend on where the radiation is aimed. Some side effects show up quickly. Others might not show up until 1 to 2 years after treatment. Ask your cancer care team what to watch for and when to call your doctor.
• Whole-brain radiation: If the cancer is in many areas, sometimes the whole brain is treated with radiation. The side effects of whole brain radiation therapy may not be noticeable until a few weeks after treatment begins.

Short-term side effects of radiation therapy to the brain

Radiation to the brain can cause these short-term side effects:

• Headaches
• Hair loss
• Nausea
• Vomiting
• Extreme tiredness (fatigue)
• Hearing loss
• Skin and scalp changes
• Dizziness
• Trouble with memory and speech
• Seizures

Some of these side effects happen because radiation can cause your brain to swell. Medicines are usually given to prevent brain swelling, but it’s important to tell your cancer care team about headaches or any other symptoms.

Treatment affects each person differently, and you may not have these side effects.

Late side effects

Radiation to the brain can also have side effects that show up later. These usually start anywhere from 6 months to years after treatment ends.

Delayed effects can include:

• Memory loss
• Stroke-like symptoms
• Poor brain function
• Radiation necrosis (tissue death due to radiation)
• Increased risk of having another tumor in the area, although this is rare.

Ask your cancer care team what to expect from your specific treatment plan.

Side effects of radiation to the head and neck can include:

• Soreness (or even open sores) in the mouth or throat
• Dry mouth
• Trouble swallowing
• Changes in taste
• Nausea
• Earaches
• Tooth decay
• Swelling in the gums, throat, or neck
• Hair loss
• Changes in skin texture
• Jaw stiffness
• Thyroid problems
• Osteonecrosis of the jaw (death of the bone in the jaw)

You can learn more about these side effects and how to manage them in Side Effects.

How to care for your mouth during treatment

If you get radiation therapy to your head or neck, you need to take good care of your teeth, gums, mouth, and throat. To help you manage mouth problems:

Stay away from food and drinks that irritate your mouth.

• Avoid spicy and rough foods, like raw vegetables, dry crackers, and nuts.
• Avoid very hot or very cold food or drinks.
• Stay away from sugary snacks.
• Don’t smoke, chew tobacco, or drink alcohol. These can make mouth sores worse.

Take steps to soothe your mouth.

• Sip cool drinks often throughout the day.
• Suck on sugar-free candy or chew gum to help keep your mouth moist.
• Moisten food with gravies and sauces to make it easier to eat.
• Ask your cancer care team about medicines to help treat mouth sores and control pain while eating.

Rinse your mouth often and carefully.

• Ask your cancer care team to recommend a good mouthwash. The alcohol in some mouthwashes can dry and irritate mouth tissues.
• Rinse your mouth with warm salt and soda water every 1 to 2 hours as needed. (1 teaspoon salt + 1 teaspoon baking soda in 1 quart of water.)

If these measures aren’t enough, ask your cancer care team for advice. Dry mouth may be a problem even after treatment is over. If so, talk to your care team about what you can do.

How to care for your teeth during treatment

Radiation therapy to your head and neck can increase your risk of cavities. This is especially true if you have dry mouth from treatment.

Dental check-ups before treatment

Ask your cancer care team if you should get a complete dental check-up before starting radiation. Ask your dentist to talk with your radiation doctor before your treatment starts.

Removing problem teeth

If you have any problem teeth, your dentist may suggest removing them before you start treatment. Radiation (and dry mouth) might damage them to the point where they’ll need to be removed anyway. This can be harder to do after treatment starts.

Wearing dentures

If you wear dentures, they may no longer fit well because of swollen gums. If your dentures cause sores, these sores could get infected. You may need to stop wearing them until your radiation therapy is done.

Taking care of your teeth during treatment

Your dentist may want to see you during your radiation therapy to check your teeth, talk about caring for your mouth and teeth, and help you deal with any problems.

Most likely, you will be told to:

• Clean your teeth and gums with a very soft brush after meals and at least one other time each day.
• Use a fluoride toothpaste with no abrasives.
• Rinse your mouth well with cool water or a baking soda solution after you brush. (Use 1 teaspoon of baking soda in 1 quart of water.)
• Ask your dentist or cancer care team if it’s OK to floss during treatment. Tell your cancer care team if this causes bleeding or other problems.

Radiation to the breast can affect your heart or lungs and cause other side effects.

Short-term side effects

Radiation to the breast can cause:

• Skin irritation, dryness, and color changes
• Breast soreness
• Breast swelling from fluid build-up (lymphedema)

To avoid irritating the skin around the breast, try to go without a bra. If this isn’t possible, wear a soft cotton bra without underwires.

If your shoulders feel stiff, ask your cancer care team about exercises to keep them moving freely.

Breast soreness, color changes, and fluid build-up (lymphedema) usually go away 1 or 2 months after radiation therapy ends. If your fluid build-up doesn’t go away, ask your cancer care team what steps you can take.

See Lymphedema for more information.

Long-term changes to the breast

Radiation therapy may cause long-term changes in the breast, including:

Changes to the look and feel of skin:

• Your skin may be slightly darker.
• Pores may be larger and more noticeable.
• Skin may be more sensitive or less sensitive.
• It might feel thicker and firmer than it was before treatment.

Changes in breast size:

• Sometimes the size of your breast changes.
• It may get larger because of fluid build-up or smaller because of scar tissue.

These side effects can last long after treatment.

Radiation treatment to the chest may cause side effects such as:

• Sore throat
• Swallowing problems
• Nausea and vomiting
• Heartburn
• Loss of appetite
• Skin changes
• Fatigue
• Cough
• Shortness of breath

Radiation can also cause other problems in your heart or lungs.

Heart complications

Radiation to the middle of the chest can raise your risk of heart disease. This risk increases with higher radiation doses and larger treatment areas in this part of your body.

Radiation can also cause heart valve damage, irregular heartbeats, or hardening of the arteries. Hardening of the arteries can increase your risk of a heart attack later.

Radiation pneumonitis

Radiation pneumonitis is inflammation of the lungs caused by radiation treatment to the chest (or less often, the breast).

It may happen about 3 to 6 months after getting radiation therapy. It’s more likely to happen if you have other lung diseases, like emphysema (which involves gradual damage of lung tissue).

Common symptoms of radiation pneumonitis include:

• Shortness of breath that usually gets worse with exercise
• Chest pain, which is often worse when taking a deep breath
• Cough
• Pink-tinged sputum
• Low-grade fever
• Weakness

Sometimes, there are no symptoms and radiation pneumonitis is found on a chest x-ray.

Symptoms often go away on their own, but some people need treatment to lower the inflammation. Steroids like prednisone are usually used.

With treatment, most people recover without any long-term effects. But if it continues, it can lead to pulmonary fibrosis (stiffening or scarring of the lungs). When this happens, the lungs can no longer fully inflate and take in air.

Ask your cancer care team what to look for and tell them if you notice any of these side effects.

If you get radiation to your stomach or some part of your abdomen (belly), you may have side effects such as:

• Nausea
• Vomiting
• Heartburn
• Belly cramps
• Diarrhea
• Constipation

Eating or avoiding certain foods can help with some of these problems, so diet planning is an important part of radiation treatment to the abdomen.

Ask your cancer care team what you can expect and what medicines you should take to help relieve these problems. Check with them before using any home remedies or over-the-counter drugs.

These problems should get better when treatment is over.

Managing nausea

Some people feel queasy for a few hours right after radiation therapy. If you have this problem, try not eating for a couple of hours before and after your treatment. You may handle the treatment better on an empty stomach.

If the problem doesn’t go away, ask your cancer care team about medicines to help prevent and treat nausea. Be sure to take the medicine exactly as you are told.

If you notice nausea before treatment, try eating a bland snack like toast or crackers. Try to relax as much as possible. See Nausea and Vomiting to learn more about managing these side effects.

Managing diarrhea

You may have diarrhea at some point after starting radiation therapy to your abdomen. Your cancer care team might prescribe medicines or give you special instructions to help with the problem.

Your cancer care team might also recommend diet changes, such as:

• Try a clear liquid diet. As soon as diarrhea starts or when you feel like it’s going to start, switch to a clear liquid diet (water, weak tea, apple juice, peach nectar, clear broth, popsicles, and plain gelatin).
• Avoid certain foods. Avoid high-fiber foods and foods that cause gas or cramps, like raw fruits and vegetables, beans, cabbage, whole-grain breads and cereals, sweets, and spicy foods.
• Eat frequent, small meals.
• Avoid milk or milk products if they irritate your bowels.
• When your diarrhea starts to improve, try eating small amounts of low-fiber foods like rice, bananas, applesauce, yogurt, mashed potatoes, low-fat cottage cheese, and dry toast.
• Be sure you take in enough potassium (found in bananas, potatoes, beans, peaches, and many other foods). This is an important mineral you may lose through diarrhea.

Radiation therapy to the pelvis or rectum (such as treatment for bladder, ovarian, rectal, or prostate cancer) can cause side effects that include:

• Rectal problems
• Bladder problems
• Fertility problems
• Sexual side effects

You might also have some of the same problems people get from radiation to the abdomen, such as nausea, vomiting, and belly cramping.

Short-term rectal problems

Radiation to the pelvis and rectum can cause side effects that include:

• Constipation
• Diarrhea
• Bowel urgency
• Skin irritation of the rectum and anus
• Blood in your stool

Usually, these side effects go away shortly after radiation treatment ends, but sometimes they continue.

Longer-term rectal problems

Longer-term problems can include:

• Bowel incontinence/urgency. You may have trouble controlling your bowels and may leak stool (poop). This sometimes continues after radiation ends. If it can’t be corrected, it can still be helped. See Bowel Incontinence to learn more.
• Radiation proctitis. If radiation damages the lining of your rectum, radiation proctitis can be a long-term problem. People with radiation proctitis may have belly/pelvis pain, blood in the stool, stool incontinence, difficulty absorbing nutrients, and a stricture (narrowing) of the rectum. If you have any of these symptoms 3-6 months after radiation therapy, talk to your cancer care team about ways to manage them.

Short-term bladder problems

Radiation to the pelvis and rectum can cause problems with urination, including:

• Pain or burning sensations
• Trouble passing urine
• Blood in the urine
• An urge to urinate often

Longer-term bladder problems

Most bladder problems get better over time, but radiation therapy can cause longer-term side effects:

• Radiation cystitis. If radiation damages the lining of your bladder, radiation cystitis can be a long-term problem that causes blood in your urine or pain when passing urine (peeing).
• Urinary incontinence. You may be unable to control your urine or have leakage and dribbling after radiation treatment for certain cancers, such as prostate and bladder cancer. This is called incontinence. There are several types and degrees of incontinence, but it can be treated. Even if it can’t be fixed completely, it can still be helped. See Bladder and Bowel Incontinence to learn more.
• Fistulas. In rare cases, radiation can cause an opening called a fistula to form between organs in the pelvis, such as between the vagina and the bladder, or between the bladder and the rectum. This can be fixed with surgery.