Radiation Therapy

What Is Radiation Therapy?

Radiation therapy is one of several treatments used to treat cancer by itself or in combination with other forms of treatment, most often surgery or chemotherapy. Radiation therapy is also called radiotherapy.

You’ve probably seen an X-ray of your teeth or some other part of your body. At high doses – many times greater than those used for X-ray exams – radiation can kill cancer cells and shrink tumors. More than half of all cancer patients receive some radiation therapy as part of their treatment.

Radiation is given either externally, through external beam radiation, or increasingly through internal radiation, also called brachytherapy. New research is focusing using special cells within the body (called monoclonal antibodies) to deliver radiation therapy directly to the cancer site.

External Radiation Therapy

External beam therapy is administered just like a normal X-ray. The radiation used for external beam radiation treatments comes from special machines, such as linear accelerators, cobalt machines, or orthovoltage x-ray machines. They deliver intense treatments with pinpoint accuracy.

Two of the more common types of radiation used include x-rays and gamma rays. State and federal guidelines strictly regulate the use and care of such equipment and the patient’s safety is given the highest priority.

Internal Radiation Therapy Or Brachytherapy

Internal radiation therapy involves placing radioactive substances such as cesium, iridium, and iodine near or into cancerous cells within the body. Patients usually remain in the hospital for at least one day. Implants may be permanent or temporary. Implants can be placed:

• Within the tumor within a body cavity such as the abdomen, called intracavitary
• Directly into the cancerous area, called interstitial
• By mouth or by injection

What Is Cancer?

“Cancer” is the name for a group of diseases in which the cells from organs or tissues grow out of control. This growth can form a mass or tumor, which can displace normal cells. A tumor can spread to surrounding tissues or organs. This happens when tiny cells break off and travel throughout the body via the blood or lymph system and begin growing in new locations.

Not all tumors are cancerous. Benign tumors grow very slowly and pose little threat to a person’s health.

How Does Radiation Therapy Work?

Cancer cells reproduce faster than normal cells in the body. Radiation therapy targets these rapidly dividing cells. The radiation reacts with water in the cells and this reaction damages the DNA or genetic material in the cell that controls cell growth.

Normally, cells can repair themselves and continue growing. But since cancer cells can’t repair themselves as easily, they die. Although normal cells are also affected, they repair themselves more effectively.

Radiation therapy has undergone major advances in recent years. The use of computers, highly sophisticated equipment and new understandings of how cancer cells work have made radiation safer than ever.

Doctors are extremely careful to limit damage to healthy tissue by:

• Precisely targeting radiation beams directly at the cancerous area
• Dividing treatments into several small sessions, called fractions
• Making sure equipment is in top working order
• Using the minimal effective dose

Patients usually receive external beam therapy for five days in a row, with a rest over the weekend. Receiving small frequent doses with brief rests limits damage to healthy cells, while effectively destroying cancer cells.

When Is Radiation Therapy Used?

Both internal and external radiation therapy can be used as:

• Curative therapy, where the goal is to eliminate all signs of cancer.
• Palliative therapy, which relieves symptoms, including pain. Lower doses are given over a shorter period of time.
• Adjuvant Therapy, which means using it in combination with other in combination with surgery, chemotherapy (use of anti-cancer drugs that destroy cancer cells), hormone therapy, or other treatments.

Adjuvant radiation therapy can be used:

• Before surgery to shrink a tumor, called neoadjuvant therapy.
• With or after chemotherapy, which can make tumors more receptive to radiation therapy.
• After surgery to make sure all cancer cells are destroyed (adjuvant).

Total Body Irradiation

This form of radiation therapy is used in conjunction with a bone marrow transplant. One large dose (or six to eight smaller doses) is given to the entire body to destroy cancer cells.

One major disadvantage is that healthy bone marrow is also destroyed. But then new bone marrow cells, taken from either a donor or the patient before irradiation, are given back to the patient after the high-dose radiation. These new cells replace the damaged bone marrow cells and rebuild a person’s immune system (the system in the body that fights infection and disease).

What Happens If I Need Radiation Therapy?

If you need radiation therapy, you may have to travel to a larger hospital or freestanding radiation therapy center. When medically possible, external beam radiation can be provided on an outpatient basis. Patients usually require a short hospital stay for internal radiation.

You may be sent to a radiation oncologist for a consultation. A radiation oncologist is a specialist who prescribes the type and amount of treatment that is right for you. During this visit, you and the doctor will discuss

• The type of cancer you have and treatment options
• Your medical history
• Any medications you may be taking, if you have any allergies, or if you are using alternative or complementary therapies (supplements, herbal therapies)
• How the treatment might affect your normal activities
• Why this method was chosen over other available options
• Any side effects that may occur

Before any treatment begins, you will undergo a physical exam and possibly more tests or x-rays.

Planning Your Treatment

Once radiation therapy is chosen as a treatment option, the radiation oncologist begins planning your treatment. He or she works closely with a medical radiation physicist, who ensures linear accelerators and other equipment deliver the proper amount of radiation, and a dosimetrist, who has special training in planning radiation therapy sessions.

Patients can receive external beam radiation, internal radiation (brachytherapy), or both. The radiation oncologist will plan out the total dose of radiation, which is divided into the smaller doses you will receive over the coming weeks.

The total dose of radiation and the number of treatments depend on:

• The size, location, and type of cancer you have
• Your overall health
• Other medical treatments you may be receiving

Simulation

If you will be receiving external radiation therapy, you will undergo a process called simulation. Using CT scans, computers, and precise measurements, this highly detailed process maps out the exact location where the radiation will be targeted. This area is called the treatment field or port.

Your skin may be marked with small points that target the area to be treated. This process usually takes 30 minutes to two hours and is an essential part of treatment planning.

What Happens During External Radiation Treatment?

The most common type of machine used for external beam radiation is a linear accelerator. The prescribed dose of radiation is carefully programmed into the radiation therapy machine before your treatment.

For each session, you will change into a hospital gown or robe. Once in the treatment room, you will lie down on a treatment table. The radiation therapist positions you using the marks on your skin and customized molded forms that help you stay in place. The rest of your body is protected by shields placed between you and the machine.

During Treatment

Though you will be in the treatment room for up to 30 minutes, you receive radiation for only a few minutes. Much of the time will be spent correctly positioning you on the treatment table. During the session, the table may be moved to deliver radiation at multiple angles.

The machines used for radiation treatments are large and noisy. Their size and motion may be frightening at first, but most people get used to this. You can talk to the therapist through a microphone, and he or she can see you through a window.

A radiation oncology nurse will be available at each treatment session, helping to explain treatments, answering questions and helping you manage side effects.

During your weeks of treatment, you may also meet:

• A physician’s assistant, who can perform exams and other duties
• A radiologist, who can read x-ray and other diagnostic images
• A dietitian, who offers nutritional advice
• A physical therapist, to address any problems with movements or muscles
• A social worker, to attend to the emotional and psychological stresses of living with cancer

How Long Does The Radiation Treatment Take?

For most cancers, external radiation therapy is given four or five days a week for five to seven weeks. Taking two or three days off a week helps normal cells to recover. The course of treatment is shorter for palliative care and usually lasts two to three weeks.

Research has shown that giving many smaller doses of radiation is better than a few large doses. The treatment is as effective and damage to healthy tissues is reduced. Radiation is usually given once daily, but sometimes the daily dose is divided into two or more sessions. This is called fractionated radiation therapy.

Sometimes, treatment is split into two groups of sessions, with a week or two off in the middle.

When Is Internal Radiation Therapy Used?

Sometimes, the radiation oncologist decides the cancer is best treated using internal radiation therapy, also called brachytherapy. During this procedure, a radiation oncologist and/or surgeon surgically places the radiation source into or near the cancer cells.

This way, it’s possible to deliver a higher total dose of radiation to a smaller area than with external treatment. By limiting the amount of radiation healthy cells receive, damage to normal cells is reduced.

Internal radiation therapy is being used to treat cancers of the head and neck, breast, uterus, thyroid, cervix, and prostate. Patients can receive both internal and external radiation therapy at the same time, or consecutively.

How Is The Implant Placed In The Body?

During the implant procedure, you receive anesthesia so you do not feel any pain. The size and location of the cancer will determine the type of implant used and how it is inserted.

Implants, also called “seeds,” may be placed:

• Directly into the tumor (interstitial radiation)
• Inside a body cavity (intracavitary radiation) using special applicators
• On the surface of a tumor
• In an area from which a tumor has been removed

High-dose implants may be removed after just a few minutes or left in place a few hours. Low-dose implants usually remain longer, sometimes for a few days or even permanently. Permanent implants lose their radioactivity quickly.

Internal radiation can also be given:

• By injecting radioactive substance solution into the blood or a body cavity
• By mouth (orally)

Will I Be Radioactive?

Patients receiving internal radiation therapy may give off tiny amounts of radiation for a short time. These patients stay in the hospital in a private room. Healthcare professionals taking care of you may not be able to spend a long time in your room and may work quickly, but you will receive all the care you need. Visiting hours may be limited and visitors are told if they need to take special precautions.

How Long Does The Implant Stay In Place?

The amount of time that an implant is to be left in place depends on the amount of radioactivity needed for effective treatment. Your doctor makes that decision.

What Happens After A Temporary Implant Is Removed?

• Once the implant is removed, there is no radioactivity in your body. Hospital staff and visitors can visit as long as needed.
• Though you may need some extra sleep or rest once home, you should feel stronger quickly.
• The treated area may be sore or sensitive for some time. Once that area is healed, you should be able to resume normal activities.

Radiation Therapy: What Are The Side Effects Of Treatment?

Patients undergoing radiation therapy usually experience side effects in the areas being treated. There are often ways to treat these symptoms. Be sure to tell your doctor or nurse if you experience any of the following side effects.

• Tiredness, lack of energy and fatigue
• Nausea and vomiting
• Diarrhea
• Hair loss
• Low blood counts
• Mouth problems
• Skin problems
• Loss of appetite
• Anxiety, depression and grief

Tiredness, Lack Of Energy And Fatigue

Fatigue is a common symptom of radiation therapy. But it also is sometimes the hardest to describe and the easiest to overlook. It’s common to hear patients say they have no energy. This feeling can be caused by:

• The disease itself or its treatment
• Lowered blood counts
• Lack of sleep
• Pain
• Poor appetite

Most people begin to feel tired after the second or third week of therapy. Fatigue gradually disappears after treatment is complete. To maximize your energy:

• Rest as much as possible during and after your course of treatments.
• At the same time, too much rest can be troublesome. Combat fatigue with appropriate exercise. Ask your nurse or doctor about exercises that can help.
• Prioritize! Decide which activities are most important and complete only those.
• Tell your doctor if you are experiencing fatigue. A blood test will reveal if your blood counts are low.
• Eat a healthy diet. A poor diet robs your body of the nutrients it needs to heal. A dietitian can help plan a healthy food program.
• If you need help with daily chores, ask friends or family members to help out.
• Consider joining a support group, which may help you learn how to deal with fatigue and emotional stress, which can worsen fatigue.
• Ask your employer about ways to customize your work schedule. Consider taking time off, working part-time, or working from home if possible.

Nausea And Vomiting

Radiation treatment causes nausea and vomiting usually only if the stomach or abdomen is exposed to the treatment. Nausea and/or vomiting usually occur one or two hours after undergoing a treatment. There are other causes of nausea and vomiting that should be explored if symptoms persist.

To reduce nausea and vomiting:

• Ask your doctor, nurse or dietitian for guidelines about which foods to eat.
• Eat small meals.
• Eat often and try to eat and drink slowly.
• Avoid fried foods or those high in fat.
• Drink cool liquids between meals.
• Eat foods that have only a mild aroma and can be served cool or at room temperature.
• For severe nausea and vomiting, try a clear liquid diet (broth and clear juices) or bland foods that are easy to digest, such as dry toast and gelatin.

If this problem persists, tell your doctor. He or she can prescribe an antiemetic medicine to prevent nausea.

Diarrhea

Patients who undergo radiation therapy to the lower abdomen may experience treatment-related or disease-related diarrhea. It’s important to tell your doctor immediately if this happens to you, to minimize potentially serious complications. Medications can often help relieve symptoms.

It may be helpful to avoid these foods:

• Dairy products, including milk and ice cream. Sometimes, yogurt, buttermilk, and other similar foods are better tolerated.
• High-fiber foods, including raw fruits and vegetables, whole grain breads
• Spicy foods and caffeine

There are other causes of diarrhea that should be explored if symptoms persist.

Hair Loss

Unlike chemotherapy, radiation therapy causes hair loss only in the area being treated. Higher doses usually result in more hair loss.

Hair loss is often cited as having a great impact on a patient’s psychological state. It’s important for patients to have a strong supportive environment during therapy. If you expect to have radiation therapy to the head or neck area, look for a wig that matches your hair color and style before treatment begins.

Hair will usually begin to grow back once treatment is stopped. Receiving chemotherapy at the same time as radiation therapy can affect how hair grows back. Regrowth also depends on how much and the type of radiation therapy you received.

It’s important to cover your head with a hat, scarf or turban, especially when in the sun or during cold weather.

Low Blood Counts

Radiation therapy can reduce the amounts of white blood cells in your blood, which fight infection, and platelets, which help blood to clot. Your doctor may check your blood counts during treatment. If they are low, a treatment may be delayed. Fatigue may be a symptom of low blood counts.

Mouth Problems

If you are receiving radiation to the head or neck, you may experience:

• Mouth or throat pain
• Lack of saliva
• Increased cavities
• Sores near or around dentures
• Difficulty eating

Always talk to your doctor if you experience any or all of these symptoms.

To alleviate problems:

• Drink plenty of water and other liquids. This will help wash out your mouth and relieve dryness. Avoid alcohol.
• Moist, soft foods may be easier to eat.
• Use liquid supplements if eating solid foods is too hard.
• Practice good care for your teeth, using a fluoride toothpaste that has no abrasives and gentle flossing.
• Keep an eye on dentures to make sure they are not creating sores where they rub on your gums.
• If need be, your doctor can recommend medicines to alleviate throat and mouth pain.

Skin Problems

Radiation therapy can irritate your skin in the area that is treated. This irritation may last throughout treatment and should gradually improve some time after treatment ends.

You may notice your affected skin:

• Looks red and is sore
• Is dry and may itch
• Is darker than your other skin

It’s important to treat your skin very gently by:

• Using lukewarm (not hot) water and a mild soap to wash. You may need to be careful to avoid washing off the marks used to pinpoint your treatment.
• Avoiding tight or itchy clothing
• Asking before you use any creams, sunscreen or lotions on the area
• Not placing hot and cold objects, such as heating pads, on the area
• Not rubbing or scratching the area

If you are going outside in the sun, cover the sensitive area.

Loss Of Appetite

One of the most important ways you can keep up your energy level and help your body heal is by eating a balanced diet. But what happens if you lose your appetite?

This can happen if:

• You receive radiation therapy in the abdominal area and feel nauseous
• You may be fatigued and feel too tired to eat
• You receive radiation therapy to the head or neck area, which can change the way food tastes or decrease the amount of saliva in your mouth

Your doctor will monitor your weight carefully during treatment. It’s not unusual for patients to lose a pound or two each week of treatment.

Try these steps to increase your appetite and give your body the nutrients it needs during treatment:

• Wait one or two hours after a treatment before eating.
• Eat small meals often and eat a variety of different foods.
• You may feel more like eating over the weekend or earlier in the week, when the effects diminish during the break from treatment.
• When deciding what to eat, try to eat foods high in protein and calories. Protein foods include meats, eggs, legumes, and nuts. Foods high in calories include fats (butter, oils and margarine), creamed soups, cheeses, milkshakes.
• Nutritional bars may be appealing and supply both calories and good nutrition.
• Relaxation techniques can help calm nervous stomachs.

If you find liquids more appealing than solid foods, try liquid supplements added to milk or other beverages you enjoy. You might want to try making a shake from fruit, yogurt, milk or other healthy foods.

Anxiety, Depression And Grief

Confronting cancer commonly causes wide-ranging feelings of anxiety, fear, nervousness, and bouts of depression and grief. Anxiety is common in cancer patients. It can be described as vague, uneasy, and unpleasant feelings of potential harm or distress.

Radiation therapy does not directly cause such distress. However, it can contribute to fatigue and change a patient’s hormone balance, which can affect your emotions.

Don’t suffer alone. Your emotional state can affect your overall health and recovery. Tell your doctor if you have feelings of hopelessness and despair. It may help to talk about your feelings and concerns with a close friend, family member, or mental health professional.

Medications are also available. Support groups allows patients to share feelings with others going through similar experiences. There may be a support group where you are being treated.

Radiation Therapy: Frequently Asked Questions

Here are some frequently asked questions related to radiation therapy.

Q: Will I be radioactive?

A: External radiation therapy does not make you radioactive and you do not have to take any precautions. Patients who undergo internal radiation therapy stay in hospital a short time. Special precautions are taken while the implant is in place. When treatment is over, there is no danger to other people.

Q: I’ve heard that radiation therapy can cause cancer. Is that true?

A: Brief high doses of radiation that damage or destroy cancer cells can also injure or kill normal cells. Side effects of radiation treatment are well known and can be easily treated. Although there is a risk of cancer from radiation therapy, this risk is usually less than the benefit obtained from killing cancer cells. Your doctor will advise you to have any treatment only when the benefits – controlling the disease and getting relief from symptoms – are greater than the known risks.

Q: What happens after radiation therapy?

A: During your weeks of treatment, you will be monitored by the radiation oncologist at regularly scheduled visits. During these check-ups, your doctor will

• Discuss and monitor any side effects you experience from radiation treatments

   

• Check for any signs of recurrent disease

   

• Perform a physical exam

   

• Possibly send you for lab tests and/or x-rays

   

• Answer any questions you have

   

Once all treatments are completed, the radiation oncologist will want to see you for follow-up and will coordinate additional visits with other doctors involved in your care. Follow-up care might include:

• More cancer treatment

   

• Routine blood tests, x-ray images and lab work

   

• Rehabilitation

   

• Counseling

   

Taking good care of yourself is an important part of following through after radiation treatments.

Q: Can I wash during treatment?

A: Ask the nurse or doctor if you can wash the area being treated. You can wash any other part of your body.

Q: Does radiation therapy cause infertility?

A: Radiation therapy only causes infertility if radiation beams pass through the testes in men or ovaries in women. Most radiation therapy does not affect these areas and does not result in infertility. Physicians may that recommend women of childbearing age avoid becoming pregnant for some period after treatment, so it is important to consider contraception during this time.

Radiation Therapy: Putting It All Together

Here is a summary of the important facts and information related to radiation therapy.

• Radiation therapy involves the use of high doses of radiation to kill cancer cells.
• New advances have made radiation therapy safer and more effective than ever.
• External radiation treatments are scheduled four or five days a week for several weeks. You must complete all sessions to achieve the best result.
• Internal radiation therapy is now being used for more types of cancer.
• If you experience side effects, tell your doctor or nurse right away.
• Take good care of yourself by resting when you can and eating properly.
• Seek the counsel of a friend, family member, or healthcare professional if you feel emotionally overwhelmed.
• Skin in the treated area may become sensitive and easily irritated.

Radiation Therapy: Glossary

Here are definitions of medical terms related to radiation therapy.

Adjuvant: Using therapies such as surgery, chemotherapy or radiation therapy in combination to achieve more effective results than using a treatment alone.

Anesthesia: Loss of feeling or sensation to prevent pain so that surgery or other procedures can take place. A local anesthetic causes loss of feeling in a part of the body, while a general anesthetic puts the patient to sleep.

Antiemetics: Drugs that prevent or relieve nausea and vomiting.

Brachytherapy: A form of radiation therapy that places radioactive substances in direct contact with the tissue being treated.

Cancer: Diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread through the blood stream and lymphatic system to other parts of the body.

Catheter: A thin, flexible, hollow surgical tube used to put fluids into or take fluids out of the body. Catheters are sometimes used to place radioactive materials near cancerous tissue.

Chemotherapy: Treating cancer with drugs that are given by mouth or intravenously. Can be used alone or in combination with surgery and/or radiation therapy or other treatments.

Cobalt: A radioactive substance used as a radiation source to treat cancer.

Dietitian (also “registered dietitian”): A health professional who advises patients about nutrition and plans proper diets.

Dosimetrist: A person who plans and calculates the proper radiation dose for treatment.

Gamma rays: Powerful and penetrating rays that can be used in radiation therapy to kill cancer cells.

Electron beam: A stream of electrons (small negatively charged particles found in atoms) that are used for radiation therapy.

External radiation: Using radiation from a machine that aims high-energy rays at cancer cells.

Fractionated radiation: Radiation treatment that is given in smaller-than-usual doses two or more times a day.

Implant: Also called a “seed,” it is the combination of a the radioactive source placed in a small holder that is inserted in the body in or near a cancer.

Internal radiation: Radiation therapy that uses the technique of placing a radioactive source in or near a cancer.

Interstitial radiation: A radioactive source (implant) placed directly into the cancerous tissue such as the head and neck region or the breast. Also called brachytherapy.

Intracavitary radiation: A radioactive source (implant) placed in a body cavity such as the chest cavity or the vagina.

Medical oncologist: A doctor who specializes in treating cancer with chemotherapy, hormones, and biotherapy, and often oversees the total care a cancer patient receives.

Medical radiation physicist: A person who makes sure the radiation machine delivers the exact amount of radiation to the treatment site. In consultation with the radiation oncologist, the physicist also determines the treatment schedule that will have the best chance of killing the most cancer cells.

Oncologist: A doctor who specializes in treating cancer.

Palliative care, palliation: Treatment that relieves symptoms and pain but does not cure disease. Palliative care can help people with cancer live more comfortably.

Primary treatment: The treatment used first or alone to treat cancer.

Radiation: Electromagnetic energy carried by waves or a stream of particles.

Radiation nurse: A nurse who specializes in caring for people undergoing radiation therapy.

Radiation oncologist: A doctor who specializes in treating cancer with radiation.

Radiation therapist: A person who runs the equipment that delivers the radiation.

Radiation therapy: Also known as radiation therapy, x-ray therapy, radiotherapy, or irradiation. Treatment with high-energy rays (such as x-rays) to kill cancer cells. The radiation may come from outside of the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). Types of radiation include x-rays, electron beams, gamma rays, neutron beams, and proton beams. Radioactive substances include cobalt, iridium, and cesium. (See also gamma rays, brachytherapy, and x-ray.)

Radioactive: Capable of emitting high-energy rays or particles.

Radiologist: A doctor with special training in using and interpreting images of areas inside the body to diagnose and treat diseases. The images are produced with x-rays, sound waves, or other types of energy.

Recurrent: Reappearance of cancer cells at the same site or in another location after a disease-free period.

Red blood cells: Cells in the blood that carry oxygen to cells throughout the body. Also called “erythrocytes.”

Simulation: The process used to plan radiation therapy so that the target area is precisely located and marked.

Treatment port or treatment field: The place on the body at which the radiation beam is aimed.

Tumor: An abnormal growth of excess tissue that results from excessive cell division. Tumors perform no useful body function and may be either benign (not cancerous) or malignant (cancerous).

White blood cells: Cells that circulate in the blood and the lymph system that help fight infection and disease. They are a part of the immune system.

X-rays: High-energy penetrating radiation used in low doses to diagnose disease and in high doses to treat cancer.

Radiation Therapy: Additional Sources Of Information

Here are some reliable sources that can provide more information on radiation therapy.

American Cancer Society (ACS) 
Phone: (800) ACS-2345 / (800)227-2345 (toll-free hotline)

www.cancer.org

National Cancer Institute (NCI), Cancer Information Service 
Phone: (800) 4-CANCER
Phone: 800-422-6237

www.nci.nih.gov

American Society for Therapeutic Radiology and Oncology 
Phone: (800) 962-7876

Online booklet – Treating Cancer with Radiation Therapy

http://www.astro.org