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Radiation Therapy

Side Effects of Radiation Therapy

Although patients do not feel anything during a radiation treatment, the effects of radiation gradually build up over time. Most patients have very few initial side effects; however, many patients experience fatigue as treatment continues.

The vast majority of patients are able to complete radiation therapy without significant difficulty. Side effects and potential complications of radiation therapy are infrequent and, when they do occur, are typically limited to the areas that are receiving treatment with radiation. The chance of experiencing side effects, however, is highly variable. A dose that causes some discomfort in one patient may cause no side effects in other patients. If side effects occur, you should inform the technologists and radiation oncologist, because treatment is almost always available and effective. Side effects are usually temporary and resolve once the radiation is completed.

The most common side effect of radiation are:

Side effects that commonly occur with radiation to the head and neck are:

Other less common side effects are:

While not as common with the advent of modern radiation delivery techniques, side effects that may occur with radiation to the chest are:

In addition to the above temporary side effects, in certain cases, patients may develop long-term side effects, also called “late complications”, such as:

These long-term side effects are also less common with the advent of modern radiation techniques.

Most Common Side Effects of Radiation Therapy

Skin reaction: A common side effect of radiation therapy is skin irritation in the area of the body that is being treated. The skin reaction can range from mild redness and dryness (similar to a sunburn) to severe peeling (desquamation) of the skin in some patients. The majority of skin reactions to radiation therapy go away a few weeks after treatment is completed. In some cases, the treated skin will remain slightly darker than it was before and it may continue to be more sensitive to sun exposure.

It is important to notify your nurse or physician when your skin becomes irritated because redness and dryness can eventually progress to peeling with oozing of fluid in the area. They can suggest measures to relieve your discomfort and possibly minimize further irritation. There are effective topical medications for treatment of radiation induced skin irritation, as well as a number of precautions that may minimize skin irritation during radiation therapy, such as:

Fatigue: Fatigue is a feeling of tiredness, weariness, weakness, exhaustion, or a profound lack of energy. Fatigue is one of the most common side effects of radiation therapy. Patients are not restricted from normal activity during radiation therapy; however, they should balance normal activity with periods of rest. Fatigue is typically more severe 2-4 hours after treatment. The feeling of fatigue should wear off several weeks after the completion of radiation therapy. The following suggestions may help you manage fatigue resulting from radiation therapy:

Side Effects Associated with Radiation Therapy to the Head and Neck

Mucositis (sore mouth or throat): Radiation therapy that is delivered to the head and neck area may cause mucositis. Mucositis is inflammation of the lining of the mouth and throat, called the mucus membranes. When radiation is administered directly to or near the head and neck region, chest, abdomen, or anal-rectal regions, it may cause damage to the mucosal lining of the entire gastrointestinal tract. This results in inflammation and sloughing of the mucosal cells, causing pain and increasing the risk of infection.

Patients who have a sore mouth or gums need to take special care of their teeth, as they are a primary site for infection and pain. These patients may need to utilize frequent oral hygienic measures and antiseptic mouthwashes. In addition, some patients find it helpful to rinse the mouth with water frequently in order to remove food and bacteria and promote healing.
Patients with mucositis should also select foods that will not further irritate an already tender mouth, for example:

Xerostomia (dry mouth): Radiation therapy that is delivered to the head and neck area may also result in xerostomia. Xerostomia is a chronic dry-mouth condition, which is caused by damage to the salivary glands as a result of radiation therapy. Xerostomia can have a negative effect on quality of life by greatly impairing a patient’s ability to speak, chew, swallow, and taste. Coping with a dry mouth can be difficult, but the following tips may help.

Changed sense of taste and/or smell: Radiation therapy or cancer itself may cause a change of taste or smell that typically goes away once treatment is complete. Foods may have a bitter or metallic taste, or simply less taste. The following is a list of suggestions that may help to make food taste better.

Less Common Side Effects of Radiation Therapy

Hair loss: Radiation therapy only causes hair loss in the area being treated. Hair loss typically begins 2-4 weeks after the initiation of treatments. Some individuals experience thinning of the hair, while others experience complete hair loss. Hair loss caused by radiation is temporary. Typically, regrowth of hair begins 6-8 weeks after completion of radiation therapy. The best way to deal with hair loss is to prepare for it before it happens. Your physician will inform you of your chances for hair loss before your treatments begin. Consider the following tips for coping with hair loss:

Nausea/vomiting: Sometimes radiation therapy causes nausea (feeling queasy or sick to your stomach) and/or vomiting (throwing up), especially when the radiation is delivered to the abdominal area. Nausea/vomiting can happen immediately after radiation, can be delayed, or can occur in anticipation of receiving treatment.  Several drugs, called antiemetics, are FDA approved for the prevention of nausea and vomiting.

If you do experience nausea immediately after radiation, you may find it helpful to refrain from eating several hours prior to the treatment and for 1-2 hours afterward. In contrast, if you experience anticipatory nausea, it might be helpful to eat a bland snack, such as toast or crackers, before treatment. The following is a list of suggestions for coping with nausea:

Diarrhea: Radiation treatment that is delivered to the abdominal area can cause diarrhea, which usually begins in the third or fourth week of radiation therapy. Your physician may recommend that you change your diet and/or prescribe medicine to help with the diarrhea. The following may help you manage diarrhea:

Loss of appetite: Loss of appetite is a common factor with cancer and its treatment. Nausea, vomiting, and depression can contribute to a loss of appetite. While you may not want to eat, it is important to maintain proper nutrition throughout treatment. The following suggestions may help you maintain your nutritional intake:

Low blood counts (myelosuppression): Blood counts, or the number of blood cells in circulation, can be affected by radiation therapy. Many radiation therapy institutions make it a policy to check the blood counts at least once during the radiation treatments. Low blood counts may cause changes in sleep or rest patterns during the radiation therapy period and some patients describe a sense of tiredness and fatigue. Notify your nurse or doctor if you experience any of these symptoms because treatment is available for low blood counts.

Other less common side effects may occur in certain situations and will be discussed with you as appropriate.

Possible Side Effects with Radiation to the Chest

Lung fibrosis: Lung fibrosis is scarring of the lung tissue and causes difficulty breathing. Fibrosis can be a significant long-term (late) complication following radiation treatment for Hodgkin’s disease and other cancers requiring radiation to the lungs. However, this decrease in lung function appears to improve over time and is thought to be reversible.

Heart complications: Heart disease is also a late complication of radiation to the middle portion of the torso, called the mediastinum. The risk of heart disease increases with higher radiation doses and larger field sizes.

Possible Long-Term Side Effects of Radiation Therapy

Secondary cancers: A second cancer can be induced by cancer treatment, including radiation, chemotherapy, or the combination of radiation and chemotherapy. Treatment for Hodgkin’s lymphoma at a young age will ultimately result in a higher incidence of second cancers.

Hypothyroidism: Hypothyroidism (abnormally low levels of thyroid hormone) is one of the more frequently encountered late complications of radiation therapy in patients where the radiation field includes the neck. This may occur in up to one-third of patients receiving radiation therapy. It is important for patients who have received radiation therapy to be tested on a regular basis because signs and symptoms of hypothyroidism occur very late and are subtle.

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