Skip to navigation Skip to Content


Search Marshfield Clinic Health System
Join a world-class health system. Find jobs

Radiation Therapy - Breast Cancer Treatment

​​​​​​​​​​​​​​​​​​​​​Radiation therapy, which uses high-energy beams, is an effective and efficient means of fighting breast cancer. 

Doctors often use radiation in connection with other forms of treatment such as surgery.

Radiation attacks the DNA structure of cancer cells limiting or stopping their ability to grow. Radiation also affects healthy cells, but healthy cells are better able to repair the damage.

One of the main benefits of radiation therapy is reducing the chance of the cancer reoccurring. By some estimates, radiation therapy can reduce the risk of reoccurrence by up to 70 percent for some patients. This is why your doctor may recommend it along with other breast cancer therapies.

For example, it is impossible for a surgeon to remove every cancer cell – individual cells are too small to see or detect. These remaining cells may reproduce and form a new cancer growth. Radiation therapy following surgery improves the chances that the cancer will not return.

Your Marshfield Clinic Cancer Specialist may deliver radiation therapy in one of two basic manners, external radiation or internal radiation

External radiation is the most commonly used form of therapy. High-energy radiation exposure in the area of the cancer, usually after a lumpectomy or mastectomy, helps decrease the chances the cancer will return.

Doctors use several techniques to deliver the radiation. The course of treatment lasts five to seven weeks with treatment five days a week. Most treatments last about 30 minutes. Your doctor will determine the best method and duration of radiation therapy for your particular situation.

Internal radiation, known as brachytherapy or partial-breast radiation, involves placing radioactive "seeds" at the cancer site following surgery. The seeds remain at the cancer site for the course of treatment. Depending on the dose, the seeds remain in place for periods ranging from a few minutes to several days. How long the seeds remain at the cancer site depends on your particular situation and the intensity of the seeds.

You may receive some types of internal radiation therapy on an outpatient basis, while other methods may require you to remain in the hospital.

Researchers are studying internal radiation therapy to determine if it is as effective as external radiation therapy. The treatment is normally shorter in duration than external therapy, often one week as opposed to seven weeks.

Your doctor will determine if your cancer treatment will benefit from internal radiation therapy.

Side Effects

The side effects of radiation therapy vary depending on the type of procedure used, however skin irritation at the radiation site is the most common side effect.

Your skin will react to the radiation much like sunburn. The skin may turn pink or red and you may experience itching, burning, soreness and possibly peeling.

The degree to which you experience skin irritation depends on several factors, including strength of radiation, your normal skin color and other considerations. Many of the irritations respond to moisturizers, over-the-counter creams and medications.

Your doctor will provide specific instructions for dealing with skin irritations during your treatment.

In addition to skin irritations, you may experience fatigue. Treating breast cancer with radiation or any of the other therapies takes a toll on your body.

Your doctor can suggest steps to reduce or manage the fatigue.

Not everyone who has radiation therapy experiences major side effects, while others may encounter multiple problems. Talk to your doctor about what to expect and how to manage the side effects.

Request Appointment

Contact us for care

If this is a medical emergency, call 911.

Call: 1-866-520-2510

(Monday-Friday, 8 a.m. - 5 p.m.)