Radiation Therapy
What is radiation therapy?
Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells X-rays, gamma, and charged particles are types of radiation used for cancer treatment. About half of all cancer patients receive some type of radiation therapy sometime during the course of their treatment. (http://www.cancer.gov/cancertopics/factsheet/Therapy/radiation)
Are there different types of radiation therapy?
Yes! There are two types! The radiation may be delivered by a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, also called brachytherapy).
Are only cancer cells affected?
Sadly, no., radiation therapy can also damage normal cells, leading to side effects
What kind of side effects happed to patients who receive radiation therapy?
Radiation therapy can cause both early (acute) and late (chronic) side effects. Acute side effects occur during treatment, and chronic side effects occur months or even years after treatment ends (1). The side effects that develop depend on the area of the body being treated, the dose given per day, the total dose given, the patient’s general medical condition, and other treatments given at the same time.
Acute radiation side effects are caused by damage to rapidly dividing normal cells in the area being treated. These effects include skin irritation or damage at regions exposed to the radiation beams. Examples include damage to the salivary glands or hair loss when the head or neck area is treated, or urinary problems when the lower abdomen is treated.
Most acute effects disappear after treatment ends, though some (like salivary gland damage) can be permanent. The drug amifostine (Ethyol®) can help protect the salivary glands from radiation damage if it is given during treatment. Amifostine is the only drug approved by the FDA to protect normal tissues from radiation during treatment. This type of drug is called a radioprotector. Other potential radioprotectors are being tested in clinical trials (see Question 11).
Fatigue is a common side effect of radiation therapy regardless of which part of the body is treated. Nausea with or without vomiting is common when the abdomen is treated and occurs sometimes when the brain is treated. Medications are available to help prevent or treat nausea and vomiting during treatment.
Late side effects of radiation therapy may or may not occur. Depending on the area of the body treated, late side effects can include (1):
Fibrosis (the replacement of normal tissue with scar tissue, leading to restricted movement of the affected area).
Damage to the bowels, causing diarrhea and bleeding.
Memory loss.
Infertility (inability to have a child).
Rarely, a second cancer caused by radiation exposure.
Second cancers that develop after radiation therapy depend on the part of the body that was treated (16). For example, girls treated with radiation to the chest for Hodgkin lymphoma have an increased risk of developing breast cancer later in life. In general, the lifetime risk of a second cancer is highest in people treated for cancer as children or adolescents (16).
Whether or not a patient experiences late side effects depends on other aspects of their cancer treatment in addition to radiation therapy, as well as their individual risk factors. Some chemotherapy drugs, genetic risk factors, and lifestyle factors (such as smoking) can also increase the risk of late side effects.
Why do patients receive radiation therapy?
Radiation therapy is sometimes given with curative intent (that is, with the hope that the treatment will cure a cancer, either by eliminating a tumor, preventing cancer recurrence, or both) (1). In such cases, radiation therapy may be used alone or in combination with surgery, chemotherapy, or both.
Radiation therapy may also be given with palliative intent. Palliative