Radiation Therapy

Receiving Radiation Therapy

Radiation is delivered externally (external-beam radiation therapy), internally (brachytherapy) or systemically (radiopharmaceuticals). Radiation Therapy Options describes each of these options in more detail. Some patients may receive multiple types of radiation to treat their cancer.

What you can expect

External-beam radiation therapy

Radiation therapy is the use of high-energy X-rays, electrons, or proton beams to destroy or damage cancer cells. External-beam radiation treatments are most commonly delivered with the use of radiation machines known as linear accelerators. The X-rays generated with these machines are much higher energy compared to the X-rays used for diagnostic studies, which permits the radiation beams to kill cancer cells. New techniques, such as intensity-modulated radiation therapy, enable doctors to target the radiation dose directly to the precise site of the tumor, causing less damage to healthy cells in the pathway of the radiation beam.

When you arrive for your treatment appointments, your radiation therapist will instruct you to lie down in the position determined during your radiation simulation session. He or she might use molds or other techniques to position your body and hold it in place or set up shields to block the radiation from reaching certain parts of your body. It may take up to 10 minutes to get you set up for treatment, and most treatments last only a few minutes.

When you are correctly positioned, the radiation therapist will leave the room. He or she will still be able to see and hear you at all times during the treatment, so you can always communicate if you have concerns. When the therapist starts the linear accelerator, it may rotate around your body to reach the targeted area from different angles. It also may make buzzing, whirring, clicking or knocking sounds, but these are normal so don’t be alarmed.

The treatment itself is painless, and most patients are treated on an outpatient basis, maintaining the ability to carry on with normal daily activities.

Proton therapy

Proton-beam therapy is a type of EBRT. It uses a type of charged particle called a proton, rather than traditional photon beams (X-rays or gamma rays), to destroy or damage the cancer cells. Protons deposit most of their energy when they reach the targeted area and their dose rapidly stops. This helps avoid treating the normal tissues that are directly behind the targeted region. This difference means that protons may reduce damage to normal tissue, often causing fewer side effects and potentially allowing for higher doses of radiation per treatment.

This process is similar to getting an X-ray. The entire process of setting up the equipment and putting you into the proper position usually takes about 15 to 30 minutes.

When you arrive, you’ll lie on a table or sit in a chair next to the radiation machine. A member of your care team will get you into your treatment position, which was determined during your radiation simulation session. This may include using immobilizing devices to hold the treatment area in place or setting up shields to block the radiation from reaching certain parts of your body.

Once you are ready, the machine will deliver the radiation to the tumor site. The machine has an arm that can be positioned around you but will not touch you. It will likely make loud clicking and whirring noises. Although the radiation therapist will control the machine from a separate room, he or she will be able to see and hear you at all times during the treatment. If at any point you are uncomfortable or feel ill, let the radiation therapist know.

Treatment should be painless and most patients are treated on an outpatient basis, maintaining the ability to carry on with normal daily activities.


If your treatment plan includes brachytherapy, the radioactive materials will probably be implanted in you in a hospital operating or procedure room. The doctor will likely use either a general anesthestic (meaning you will be asleep) or a local anesthestic to numb a specific area so that you do not feel pain during the procedure. The radioactive substance will be implanted using an applicator, which is usually a metal tube or a plastic catheter.

If you are receiving several temporary treatments, the applicator may remain in place until the final treatment, and you will need to stay in the hospital while receiving treatment. Other brachytherapy applications are given as outpatient procedures, delivered several times per week. If your internal radiation therapy is permanent, the applicator will be removed at the time of the procedure.

The dose and amount of time you are exposed internally to the radioactive substance will be determined by your radiation treatment team. Permanent radioactive seeds will eventually stop giving off radiation after weeks or months. They will stay inside your body but will not be active and will not cause harm.


Systemic radiation is delivered through radioactive drugs called radiopharmaceuticals. They may be given in a vein or taken orally. You will likely receive treatment in a hospital room designed to contain radiation. Because you will have radiation in your body for a couple of days following treatment, you may need to stay in the hospital. It is important that you follow any precautions recommended by your cancer care team to protect the people around you for a certain amount of time after you receive systemic radiation treatment.

It is important that you avoid pregnancy while receiving any type of radiation therapy. For women, radiation can cause harm to the baby. For men, there is very little information available about the effect of radiation therapy on children of men receiving radiation at the time of conception. Talk to your doctor about birth control options during and for a short time after radiation therapy.

Will I be radioactive? A common fear.

Many patients wonder if receiving radiation therapy will make them radioactive. It is important to know that the majority of patients do not emit any radioactive material during or following radiation therapy. Only the small number of patients receiving internal or systemic radiation are at risk of emitting radioactive substance surrounding treatment. Internal radiation therapy may emit small amounts of radiation, depending on the dose and whether you receive temporary or permanent implants. Permanent implants give off only very small doses over a period of a few weeks or months so the risk that others could be exposed to radiation from your treatment is minimal. Still, it is important to take precautions, such as limiting visitors while receiving temporary treatment and staying away from small children and pregnant women immediately after permanent radiation implantation. However, neither your bodily fluids nor the surfaces you touch will be radioactive during internal radiation therapy. Systemic radiation does involve a radioactive substance that circulates throughout your entire body so, for a time after receiving therapy, your bodily fluids (including urine, saliva and sweat) may emit radioactive material. For the first few days after systemic radiation therapy, you can reduce the risk of radiation exposure to family and friends by following some simple tips.

Because there is no internal source of radiation in your body, external-beam radiation does not cause you to become radioactive during or after treatment.

Safety tips for patients receiving internal or systemic radiation

  • Wash your hands thoroughly after using the toilet
  • Flush twice after using the restroom
  • Do not share utensils or towels
  • Wash your laundry separately
  • Drink plenty of fluids to help rid your body of radioactive material
  • Avoid sexual contact for at least a week, including kissing
  • Limit contact with infants, young children, pregnant women and pets
  • Consider sleeping alone for the first week

Taking care of yourself

During treatment, it is important to take care of yourself. You need to get plenty of rest, eat a healthy diet and manage side effects.

In addition to killing cancer cells, radiation may also cause damage to normal tissues. This damage can lead to unintended side effects. Which side effects you experience will depend on the area of the body being treated, the dose and treatment schedule, your overall health and whether you are receiving any other treatment during radiation. The side effects of radiation treatment can vary. Not all people will have the same side effects, even if they have the same type of radiation therapy for the same type of cancer.

Side effects that occur during treatment are called short-term side effects, and they usually disappear when treatment ends or within one to two weeks after treatment. In contrast, long-term side effects may not completely disappear until months or years after treatment ends, and late effects may emerge years later. Other side effects vary according to the part of the body being treated and may be short-term, long-term or occur long after treatment ends.

Some side effects are a minor inconvenience, while others may cause discomfort, pain and/or emotional distress. Knowing what to expect and how you can prevent or manage some of the most common side effects may help you get through treatment successfully. If you feel better, you’re more likely to complete treatment on schedule.


Fatigue is one of the most common side effects of radiation treatment. Most patients experience some degree of fatigue regardless of the area being treated. Everyone knows what exhaustion feels like, but the fatigue that can come with cancer and its treatment is different. It’s stronger and lasts longer. For some patients receiving radiation, fatigue persists even when they get enough sleep.

Radiation therapy typically takes a while to cause fatigue; a feeling of being tired and weak usually starts a few weeks after treatment begins and gradually diminishes after treatment ends. These strategies may help you manage your fatigue:

  • Accept help from others who volunteer to prepare meals, complete chores and perform other tasks.
  • Remain active. Regular moderate exercise, especially walking, decreases fatigue.
  • Set a routine for sleeping and waking.
  • Nap when you can, but not too much. Try to keep naps to about 30 minutes. Longer naps can reduce your energy level. Try to get at least eight hours of sleep per night.
  • Don’t ignore symptoms like pain, nausea, vomiting or depression, which might be preventing you from sleeping.

Skin problems

Skin reactions caused by radiation therapy often begin about two to three weeks after the first treatment and typically resolve within a few weeks after treatment ends. During your treatment you will likely experience some dryness, itchiness and irritation of the skin, similar to a mild sunburn. The skin and underlying tissues in the area being treated may become sensitive. This sensitivity is typically short-term and usually resolves gradually within two months after treatment stops. Short-term or long-term swelling or scarring of the tissues may occur, and the scarred tissues may become firm or contracted.

Talk to your doctor about using creams or lotions to alleviate short-term discomfort caused by radiation. And stay covered or wear sunscreen when outdoors to prevent further damage or sensitivity to the treatment area.

Nausea and vomiting

Nausea and vomiting are most commonly caused by radiation to the abdomen or pelvis and sometimes the brain. This can cause severe dehydration and interrupt your treatment plan. Talk to your treatment team about prescribing antiemetics or anti-nausea drugs to help keep you comfortable throughout treatment. Also try eating smaller meals throughout the day and drinking plenty of fluids.


Radiation to the abdomen or pelvis can damage the cells that line the intestines, making them unable to absorb water. This can affect your body’s ability to have regular bowel movements. If left untreated, diarrhea can become severe and even life-threatening, so talk to your doctor if you are experiencing problems. To manage diarrhea at home, try these tips:

  • Drink plenty of fluids every day, including water and other clear liquids such as broth.
  • Eat several small meals throughout the day rather than three big meals.
  • Eat bland, low-fiber foods such as boiled white rice, boiled chicken, white bread, cottage cheese and small servings of smooth peanut butter.
  • Eat foods that have potassium such as boiled or mashed potatoes and bananas.
  • Avoid alcohol, caffeine and fatty foods.
  • Talk with your radiation oncologist about using over-the-counter anti-diarrheal medications such as loperamide (Imodium).

Dry mouth

Radiation therapy to the head and neck or face can cause dry mouth. It can take six months or longer after treatment ends for saliva production to return to normal again, especially if radiation was directed at the salivary glands. It is important to visit your dentist before starting treatment to help prevent dental problems. Also try brushing with fluoride toothpaste and a soft-bristle toothbrush, flossing gently and rinsing your mouth regularly. Avoid mouthwashes that contain alcohol and use a cool mist humidifier.

Potential side effects

Listed here are the most common side effects based on the part of body treated.
- Headaches
- Hair loss
- Nausea, vomiting
- Fatigue
- Hearing loss
- Skin changes
- Problems with memory or speech
- Seizures
- Heart problems, such as hardening of the arteries, heart valve damage or irregular heartbeat
- Trouble swallowing
- Cough
- Shortness of breath
- Breast soreness, tenderness or tightening
- Skin changes, irritation
- Lymphedema (swelling, fluid buildup)
- Heart problems, such as hardening of the arteries, heart valve damage or irregular heartbeat
- Trouble swallowing
- Cough
- Shortness of breath
Stomach and abdomen
- Nausea, vomiting
- Cramping
- Diarrhea
Head and Neck
- Soreness in the mouth or throat
- Dry mouth
- Trouble swallowing
- Changes in taste
- Nausea
- Earaches
- Tooth decay
- Swelling of the gums, throat or neck
- Hair loss
- Skin changes, irritation
- Stiffness in the jaw
- Nausea, vomiting
- Cramping
- Diarrhea
- Bladder problems, such as pain or burning sensation during urination, trouble passing urine, blood in the urine or frequent urge to urinate
- Vaginal itching, burning, dryness
- Fertility problems
- Changes in sex drive

Questions to ask your radiation oncologist

Start planning your questions by reading "Q&A With Your Treatment Team" here.

  • What is the goal of treatment?
  • What are my other treatment options?
  • How do I prepare for treatment?
  • How often will I receive radiation and for how long?
  • What are the short-term side effects and how long will they last?
  • What are the long-term side effects?
  • Will treatments restrict my normal activity?
  • Will I be radioactive after treatment?
  • When do I need to call my doctor?