Frequently Asked Questions about Radiation Oncology

What are common side effects of radiation therapy?

What happens if I experience medical issues during my treatment at Fox Chase that are not cancer-related?

What can I do about skin problems?

How long does radiation therapy treatment last?

For which types of cancer is radiation therapy used?

Will radiation therapy make me radioactive?

How does the doctor measure the dose of radiation?

What is treatment planning, and why is it important?

What are the side effects of radiation therapy?

The most common side effects are fatigue, skin changes, and some loss of appetite. Other side effects usually are related to the treatment of specific areas, such as hair loss following radiation treatment to the head. Fortunately, most side effects will go away in time and you can reduce the discomfort they cause. If you have a reaction that is particularly severe, the doctor may prescribe a break in your treatments or change the kind of treatment you're receiving. It is usually not desirable to interrupt a course of radiation therapy because the delay may decrease the treatment's effectiveness.

Although unpleasant, most side effects are not serious and can be controlled with medication or diet. Tell your doctor, nurse, or radiation therapist about any side effects you notice so that they can help you treat the problems.

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What happens if I experience medical issues during my treatment at Fox Chase that are not cancer-related?

At Fox Chase, your treatment choice will be tailored based on your cancer stage, lifestyle and medical condition. Our in-house team of cardiologists, pulmonologists and internists will work with your oncologist to manage any pre-existing or new medical conditions that may arise during the course of treatment.

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What can I do about skin problems?

After radiation therapy, your skin in the treatment area may look red, irritated, sunburned or tanned. After a few weeks, it may become dry or reddened from the therapy. It is important to call your doctor or nurse of any skin changes. They may have solutions to relive your discomfort and possibly minimize further irritation. Most skin reactions should go away a few weeks after treatment is finished. In some cases, though, the treated skin will remain darker than it was before. You need to be gentle with your skin. Suggestions include:

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How long does radiation therapy treatment last?

Radiation therapy treatments are usually given daily (5 days a week) over the course of 1-10 weeks, depending on your type of cancer and the treatment given.

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For which types of cancer is radiation therapy used?

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Will radiation therapy make me radioactive?

Cancer patients receiving radiation therapy are often concerned that the treatment will make them radioactive. The answer to this question depends on the type of radiation therapy being given.

External radiation therapy will not make the patient radioactive. Patients do not need to avoid being around other people because of the treatment.

Internal radiation therapy (interstitial, intracavitary, or intraluminal) that involves sealed implants emits radioactivity, so a stay in the hospital may be needed. Certain precautions are taken to protect hospital staff and visitors. The sealed sources deliver most of their radiation mainly around the area of the implant, so while the area around the implant is radioactive, the patient's whole body is not radioactive.

Systemic radiation therapy uses unsealed radioactive materials that travel throughout the body. Some of this radioactive material will leave the body through saliva, sweat, and urine before the radioactivity decays, making these fluids radioactive. Therefore, certain precautions are sometimes used for people who come in close contact with the patient. The patient's doctor or nurse will provide information if these special precautions are needed.

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How does the doctor measure the dose of radiation?

The amount of radiation absorbed by the tissues is called the radiation dose (or dosage). Before 1985, dose was measured in a unit called a "rad" (radiation absorbed dose). Now the unit is called a gray (abbreviated as Gy). One Gy is equal to 100 rads; one centigray (abbreviated as cGy) is the same as 1 rad.

Different tissues can tolerate various amounts of radiation (measured in centigrays). For example, the liver can receive a total dose of 3,000 cGy, while the kidneys can tolerate only 1,800 cGy. The total dose of radiation is usually divided into smaller doses (called fractions) that are given daily over a specific time period. This maximizes the destruction of cancer cells while minimizing the damage to healthy tissue.

The doctor works with a figure called the therapeutic ratio. This ratio compares the damage to the cancer cells with the damage to healthy cells. Techniques are available to increase the damage to cancer cells without doing greater harm to healthy tissues.

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What is treatment planning and why is it important?

Because there are so many types of radiation and many ways to deliver it, treatment planning is a very important first step for every patient who will have radiation therapy. Before radiation therapy is given, the patient's radiation therapy team determines the amount and type of radiation the patient will receive.

If the patient will have external radiation, the radiation oncologist uses a process called simulation to define where to aim the radiation. During simulation, the patient lies very still on an examining table while the radiation therapist uses a special x-ray machine to define the treatment port or field-the exact place on the body where the radiation will be aimed. Most patients have more than one treatment port. Simulation may also involve CT scans or other imaging studies to help the radiation therapist plan how to direct the radiation. The simulation may result in some changes to the treatment plan so that the greatest possible amount of healthy tissue can be spared from receiving radiation.

The areas to receive radiation are marked with a temporary or permanent marker, tiny dots or a "tattoo" showing where the radiation should be aimed. These marks are also used to determine the exact site of the initial treatments if the patient should need radiation treatment later.

Depending on the type of radiation treatment, the radiation therapist may make body molds or other devices that keep the patient from moving during treatment. These are usually made from foam, plastic, or plaster. In some cases, the therapist will also make shields that cannot be penetrated by radiation to protect organs and tissues near the treatment field.

When the simulation is complete, the radiation therapy team meets to decide how much radiation is needed (the dose of radiation), how it should be delivered, and how many treatments the patient should have.

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For more information about radiation oncology at Fox Chase Cancer Center or to make an appointment, call 1-888-FOX CHASE (1-888-369-2427).

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