Getting a cancer diagnosis is overwhelming and scary. You must learn about your cancer and available treatment options. As part of your treatment plan, your doctor may recommend radiation therapy. In this article, you will learn important things to know about radiation that will help you decide on the best course of treatment for you.

Important things to know about radiation: The basics.

Radiation therapy, also called radiotherapy, uses energy beams that contain supercharged particles to kill cancer cells, thereby causing tumors to shrink.

Doctors use radiation to cure or reduce early-stage cancer, prevent cancer from returning, treat symptoms due to advanced cancer, and treat cancer that has come back.

Importantly, it takes days or weeks of treatment before the radiation does enough damage to the DNA for cancer cells to die. However, cancer cells keep dying for weeks or months after radiation therapy ends.

Radiation may be your only treatment, but it’s more likely you will receive it in conjunction with other treatments. For instance, you may receive radiation to shrink tumors before, during, or after you receive other cancer treatments, such as chemotherapy, immunotherapy, or surgery.

Important things to know about radiation: The difference between chemotherapy and radiation.

In radiation therapy, the treatment is targeted directly at the cancer, while avoiding as many healthy cells as possible. Since the treatment is narrowly focused, it’s not useful for cancers that may have spread to other parts of your body.

Conversely, chemotherapy drugs spread throughout the body, even if your cancer is localized. Therefore, doctors use chemotherapy to treat cancers that have spread from the original tumor to other parts of the body, and when they don’t know if a cancer has spread or not. Chemotherapy is also used on tumors they cannot surgically remove.

Similar to radiation, chemotherapy is used to cure cancer, reduce the spread of cancer cells, and to reduce pain caused by cancer. For detailed information on chemotherapy, read 6 Important Things to Know About Chemotherapy.

Important things to know about radiation: What types of therapy are available?

There are two main types of radiation therapy: external beam (more commonly used) and internal. Both treatments use radiation to kill cancer cells. What’s different is how the radiation is delivered to the cancer cells.

Your doctor will consider many factors when determining which type of radiation therapy is best for you, including the following:

Your type of cancer.
The size of your tumor.
The tumor’s location in your body.
How close the tumor is to normal tissues that are sensitive to radiation.
Your general health and medical history.
Other types of cancer treatments you will receive.
Other factors, such as your age and other medical conditions.

Important things to know about radiation: External beam radiation therapy.

During external beam radiation therapy (EBRT) a machine directs high-energy radiation beams towards the tumor. This type of radiation is used to treat many types of cancer.

The types of energy used in EBRT.

The supercharged particles used in external beam radiation therapy include:

Photons (X-rays and gamma rays), the basic building blocks of energy, can penetrate deep into your tissue, killing cancer cells. This is the most common type of energy used for EBRT.
Protons, positively charged particles, are used in a newer form of EBRT called proton therapy. In this therapy, the radiation penetrates cancer cells but doesn’t penetrate healthy cells, potentially protecting healthy tissue. Therefore, patients experience fewer side effects than with photon therapy. However, proton therapy is not widely available.
Electrons, particles with a negative charge, can’t travel as deeply into tissue as photons or protons, so electron beams are primarily used for skin cancer or tumors located close to the skin.

The types of external beam therapy.

There are many forms of external beam therapy:

3D conformal radiation therapy which directs multiple energy beams toward your tumor that “conform” or fit your tumor’s exact size and shape, based on models created using imaging and computer technology.
Intensity-modulated radiation therapy (IMRT) is an advanced form of 3D conformal radiation therapy. Not only do these energy beams fit the shape of your tumor, but each beam also contains several small beams of variable strengths.
Image-guided radiation therapy (IGRT) analyzes imaging (usually a CT scan) during every treatment session, allowing the energy beams to be repositioned based on changes to your tumor. This treatment ensures radiation beams are delivered precisely.
Stereotactic radiosurgery such as Gamma Knife surgery doesn’t require cutting despite its name. Instead, it directs high radiation doses toward small brain tumors that can’t be surgically removed.
Stereotactic body radiation therapy (SBRT) is like stereotactic radiosurgery, but doctors use it to treat tumors that are not in the brain, especially liver, lung, or spine tumors. Also, doctors use SBRT when surgery is too risky.
Intraoperative radiation (IORT) delivers radiation during surgery.
Tomotherapy/helical tomotherapy delivers radiation while you lie on a table and move through a donut-shaped machine while the radiation encircles you.

Important things to know about radiation: Internal radiation therapy.

For internal radiation therapy, a doctor will places a source of radiation inside your body, close to your cancer cells. It generally treats smaller tumors in the head, neck, breast, cervix, uterus, or prostate.

You can receive internal radiation through a solid source or in liquid form, as follows:

Brachytherapy.

Brachytherapy involves the implantation of a solid radioactive source while under anesthesia. Your doctor will place the implanted source, such as a seed, ribbon or capsule, inside or beside a tumor. The source releases radiation to a small area.

With brachytherapy, the radiation source in your body will give off radiation for a while.

Systemic therapy.

Systemic therapy sends liquid radioactive material through your blood to find and destroy cancer cells. You can receive this material orally, through a vein via an IV line, or through an injection.

With systemic radiation, your body fluids, such as urine, sweat, and saliva, will emit radiation for a while.

Important things to know about radiation: What are the pros and cons?

One of the most important things to know about radiation is that it is a reliable, effective cancer treatment that doctors have used for over 100 years. In some cancers, radiation can destroy cancer cells and help other cancer treatments work better. Additionally, radiation can ease cancer symptoms to make your life easier.

Conversely, radiation therapy can increase the likelihood that you will develop another cancer in the future. And there are side effects you will have to manage.

Before undergoing radiation treatment, talk to your radiation oncologist about the pros and cons of radiation treatment for you, considering your diagnosis, age, health history, and other relevant factors.

Important things to know about radiation: What are the possible side effects?

Importantly, radiation not only kills or slows the growth of cancer cells, but it can also harm nearby healthy cells, which can cause unpleasant side effects. To ease side effects, you will likely receive radiation therapy spread out over multiple treatment sessions, avoiding a full dose in one session and allowing your healthy tissue time to recover.

Importantly, an important thing to know about radiation is that the side effects you experience may differ from others receiving the same type of treatment to the same part of the body. Ask your radiation oncologist what side effects you can expect, and how to best manage them.

Below is information on some common radiation side effects.

Fatigue.

Many people who get radiation therapy experience fatigue, which can happen all at once or come on slowly. You may feel physically, mentally, and emotionally tired. With fatigue from radiation therapy, you may not feel better after resting.

Generally, fatigue sets in after a few weeks of radiation and unfortunately gets worse as treatment continues. And stress can make your fatigue worse. The good news is that it usually goes away after treatment ends.

Importantly, let your medical team know if your fatigue:

Doesn’t improve, keeps recurring, or worsens.
Makes you feel more tired than usual during or after an activity.
Is not related to something you have done.
Makes you confused or makes it difficult to focus.
Makes it hard to get out of bed for more than 24 hours.
Disrupts your social life or daily routine.

Ask your medical team for suggestions on easing your fatigue and its impact on your life.

Headaches.

Radiation therapy to the brain can cause headaches. Notify your doctor right away if you experience headaches. Your doctor may prescribe steroids to reduce brain swelling which can ease your headaches.

Memory or concentration difficulties.

Radiation therapy to the brain can make it hard to think, concentrate, or remember things. Some people only experience minor difficulties, while others have more significant struggles.

Follow these suggestions to help you manage minor memory or concentration problems:

Plan your day. Schedule your day so you perform tasks that require the most concentration during the time of day you feel best. Make sure you get plenty of rest – at night and during the day with short naps. Follow a daily routine.
Exercise your body and mind. Exercise for stress reduction and the release of endorphins (“feel-good chemicals”). Ask your doctor what types of light physical exercises are best for you. Also, consider mind–body practices such as meditation, and mental exercises such as puzzles or games.
Get help remembering things. Lists are your friend! Keep a list handy of important information, including contact information for key people. Use a daily planner, recorder, or other electronic device to help you remember important activities.
Don’t keep these struggles to yourself. Talk to your doctor or nurse about your difficulties and ask for suggestions, including referrals to professionals who could provide help, such as a social worker, neuropsychologist, occupational therapist, and/or vocational therapist.

Nausea and vomiting.

Radiation therapy to certain parts of the body can cause nausea and vomiting. Unfortunately, this can become serious if it leads to malnutrition and dehydration. However, you can take steps to control your nausea and vomiting which can help prevent serious health issues while also helping you feel better.

Consider these options that can help you feel better if you have nausea and vomiting:

Take anti-nausea medicine, which can prevent or reduce nausea. Follow the instructions provided by your doctor or nurse regarding which medication to take and when to take it.
Drink plenty of water and fluids to reduce the risk of dehydration which can cause serious issues. Sip on water, fruit juices, ginger ale, tea, and/or sports drinks throughout the day.
Avoid certain foods that make you feel sick, such as food that is greasy, fried, sweet, or spicy. You may find cool foods easier to tolerate than hot foods.
On treatment days, you may it helpful to eat a small snack before treatment. Conversely, some people find that avoiding food and drink right before or after treatment helps.
Complementary medicine practices may help, such as acupuncture, deep breathing, guided imagery, hypnosis, and other relaxation techniques.
Seek professional help – ask your care team for suggestions to minimize symptoms.

Diarrhea.

Radiation to the pelvis, rectum, or stomach/abdomen can lead to diarrhea. Not only can this cause discomfort, but prolonged diarrhea can leave you dehydrated and/or malnourished. Unfortunately, diarrhea that leads to dehydration and low levels of salt and potassium can be life threatening, so don’t ignore this issue. Call your doctor if you feel dizzy or lightheaded, have dark urine or have stopped urinating, or if you have a fever.

To reduce your risk of complications from diarrhea, talk to your doctor and try these suggestions:

Drink plenty of fluid each day – ask your doctor or nurse how much you need. If your diarrhea is severe, your doctor may recommend drinking only clear liquids or getting fluids through an IV.
Eat 6-8 small meals throughout the day, choosing food that are easy on your stomach and limiting foods and drinks that can make diarrhea worse. Ask your doctor or nurse if you should include foods high in potassium and sodium (minerals you lose when you have diarrhea).
Only take anti-diarrhea medications recommended by your doctor or nurse.
Keep your anal area clean and dry by using warm water and wipes to stay clean (or a bidet). Warm, shallow baths may help.

Skin irritation.

Radiation therapy can cause the skin in the treatment area to become dry and itchy. Additionally, your skin may peel, look sunburned or swollen. And you may develop painful, wet sores that become infected.

Fortunately, these problems generally go away after treatment. However, your skin may remain darker and more sensitive.

Importantly, tell your medical team about any skin changes. They can suggest ways to ease discomfort, reduce irritation, and prevent infection, including these suggestions:

Avoid skin products that can irritate your skin – ask your nurse for a list of products (creams, lotions, etc.) to avoid during radiation and for a few weeks after treatment.
Prevent infection by keeping the area clean, following your nurse’s instructions. And ask if you need antibiotics.
Moisturize your skin – but first ask your nurse which creams and lotions to use.
Avoid sun exposure by using sunscreen and lip balm and cover your skin with loose garments while outside. Don’t forget a hat!
Avoid heating pads, ice packs, and bandages in the treatment area.
Don’t shave the treatment area without asking your doctor or nurse first. And use an electric razor. If your skin is sore, don’t shave.
Minimize dry, itchy skin by avoiding products with alcohol or fragrances. Ask your nurse about oatmeal baths. And apply a cool washcloth to dry, itchy skin.
Take short showers with lukewarm water and mild soap. After showering, apply skin cream while your skin is a bit damp.

Additionally, consider these suggestions:

Avoid tight, rough-textured, or stiff clothing. Instead, wear loose, soft clothes.
Do not rub, scrub, or scratch the skin in your treatment area.
Do not use adhesive tape on treated skin. If needed, use tape made for sensitive skin, such as paper tape. And put the tape outside the treatment area, varying the tape location.

Hair loss and dry, itchy scalp.

Radiation therapy can cause hair loss on the part of your body undergoing radiation.

Importantly, to keep your hair and scalp as healthy as possible, including as your hair starts to grow back, follow these suggestions:

When brushing your hair, gently use a soft hairbrush.
Avoid hair dryers, irons, clips, gels, and other products that could hurt your scalp.
Wash your hair/scalp less often, using a mild shampoo and gentle motions.
Pat your head dry with a soft towel.
Use sunscreen or wear a hat when outside.
Use lotions and conditioners if your scalp is sore or itchy. Ask your nurse for recommendations.
Alternatively, you may choose to cut your hair short or shave it all off (use an electric razor).

Fortunately, your hair will likely grow back within 3-6 months after your radiation therapy ends. However, it may grow back thinner, or not grow back at all, if you received a very high dose of radiation.

Mouth and throat problems.

Unfortunately, radiation therapy to the chest, head or neck can harm your salivary glands and tissues in your mouth and/or make it hard to chew and swallow safely. Mouth and throat problems may include:

Changes in taste or smell.
Dry mouth.
Infections and mouth sores.
Pain or swelling in your mouth.
Sensitivity to hot or cold foods.
Swallowing problems.
Tooth decay (cavities).

If problems with your mouth prevent you from eating or drinking, you can become dehydrated or malnourished. Therefore, call your doctor or nurse if you cannot eat or drink.

Consider these suggestions:

See the dentist before you begin treatment and tell him/her about your treatment plan. Try to get dental work finished before you start radiation.
Check and clean your mouth daily – looking for sores or white spots. If you notice changes, tell your doctor or nurse. And ask your nurse for a recommended mouth rinse recipe and follow the instructions. Gently brush your teeth, gums, and tongue after eating and before bed, using very soft toothbrushes or cotton swabs. And ask your nurse about flossing during treatment.
Ease soreness by eating easily swallowed soft, wet foods. Use a blender to make milkshakes and/or to blend your food. Ask your nurse about medications to numb your mouth. And avoid irritating foods and beverages, including foods that are crunchy, salty, spicy, or sugary. Lastly, avoid alcohol and tobacco products.
Ease dryness by drinking plenty of liquids, suck on ice chips or sugar-free hard candy and eat frozen desserts. And lip balms can help. Ask your nurse about saliva substitutes. Lastly, acupuncture may help.
Improve the taste of food by adding spices or sweeteners.
See a registered dietitian for help in finding foods you can eat that taste good and provide needed nutrients.

Urinary and bladder issues.

Radiation therapy to the pelvic area (including reproductive organs, the bladder, colon, and rectum) can irritate the bladder and urinary tract. These issues often start several weeks after radiation therapy begins and go away several weeks after treatment ends.

Unfortunately, radiation to the bladder lining can cause the following symptoms:

Pain or burning when urinating.
Blood in your urine.
Trouble starting to urinate.
Difficulty in completely emptying your bladder.
Feeling you need to urinate urgently or frequently.
Leaking a little urine when you cough or sneeze.
Cramps or discomfort in the pelvic area.

Talk to your doctor or nurse for suggestions on how to feel better and prevent issues. For instance, your team may recommend you drink plenty of liquids every day. Additionally, they may suggest you avoid bladder irritants, including caffeine, alcohol, spicy foods, and tobacco products.

Sexual and fertility problems.

Radiation to the pelvic area and rectum can cause sexual and/or fertility problems in men and women. Talk to your doctor about your concerns before starting treatment.

For more information, read the American Cancer Society’s webpages on these topics, as follows:

Things to know about radiation: You may be able to work.

Your ability to work will depend on how you feel. You can ask your doctor or nurse what to expect, but since everyone is different, you won’t know for certain how you will feel until you start treatments. For instance, some people work full-time, others work only part-time, while some do not work at all during this period.

Because the impact of radiation therapy is cumulative, you will likely feel well enough to work at the beginning. However, as time passes, you may feel weak and/or fatigued. Additionally, don’t be surprised if it takes a few weeks, or even months, to feel better after you finish your radiation treatments.

If you cannot work, talk to your employer about medical leave. And if you do plan to go on medical leave, check with your health insurer about coverage.

Learn more…

In addition to learning important things to know about radiation, it’s also important to learn about other issues that can impact your care and outcome. Read the following posts for tips:

Important Things to Know About Radiation Treatment

Important things to know about radiation: The basics.

Important things to know about radiation: The difference between chemotherapy and radiation.

Important things to know about radiation: What types of therapy are available?