Some people with cancer may hesitate to have radiation therapy because they are uncertain about the treatment and the possible side effects. It is important to learn about the treatment and communicate with your health-care team if you have any further questions. The following are common questions and answers about radiation therapy.

Q: Is it true radiation cannot be controlled because it's invisible?

A: Although radiation is invisible, it can be easily controlled through the use of treatment machines. Doctors have been safely and effectively treating patients with radiation therapy for more than 100 years.

Q: Will radiation therapy cause another cancer?

A: Undergoing radiation therapy slightly increases the risk of developing a secondary cancer. However, it is important to remember that, for many people, radiation therapy can cure cancer. This benefit far outweighs the risk that the treatment could cause a cancer later in life.

Q: Does radiation therapy harm surrounding organs?

A: Since radiation is aimed precisely at the tumor and the nearby tissue surrounding the tumor, surrounding organs are usually not harmed. Temporary effects on these tissues may cause short-term side effects. Talk with your doctor about exactly where the radiation therapy will be targeted.

Q: Is radiation therapy painful?

A: Most people cannot feel radiation from the machine even during daily treatments; a few report a slight warming or tingling sensation in the area being targeted. Many of the side effects of radiation therapy are not painful and are only felt in the area being treated. For example, the skin in the area being treated may become dry, sore, itchy, or may feel sunburned.

Q: Should a person having radiation therapy avoid physical contact with friends and family because of possible radioactivity?

A: External-beam radiation therapy does not cause a person to be radioactive at any time. The radiation is delivered to the body within an instant and there is no lingering radiation once the treatment machine is turned off. However, certain precautions need to be followed to reduce exposure to others if you receive internal radiation therapy (brachytherapy or radioactive isotopes). For example, you may be instructed to avoid close physical contact with others, especially children, for a short period of time.

Q: Does radiation treatment make a person lose his or her hair?

A: Radiation therapy is a local treatment and only affects the area of the body where the tumor is. People do not lose their hair from having radiation therapy, unless it is targeted at a hair-bearing area, such as the scalp.

Q: Is it true radiation is always used with chemotherapy and/or surgery?

A: In some cases, radiation therapy is the only treatment a patient needs. For example, prostate and larynx cancers are often treated with radiation therapy alone.

Q: Is radiation only used to slow or stop cancer growth?

A: In addition to actively treating the tumor and its growth, radiation therapy can be used to reduce the symptoms caused by growing tumors and improve a person's quality of life by relieving pain. Radiation therapy can also be employed as curative treatment for many cancers.

Additional resources

American Society for Therapeutic Radiology and Oncology (ASTRO): RT Answers

Breastcancer.org: Ten Key Points About Radiation Therapy

More Information

Part I: Understanding Radiation Therapy

Part II: Radiation Therapy—Your Personal Experience

Part III: Side Effects of Radiation Therapy

Types of Treatment

Managing Side Effects