Partial breast radiation therapy - external beam


Partial breast radiation therapy uses high-powered x-rays to kill breast cancer cells. It is also called accelerated partial breast radiation (APBI). A standard course of external beam breast treatment takes 3 to 6 weeks. APBI can be accomplished in as little as 1 to 2 weeks. APBI targets a high dose of radiation on the area where the breast tumor was removed. It avoids exposing the surrounding tissue to radiation. There are three common approaches for APBI:


Radiation therapy is usually delivered on an outpatient basis, except for intraoperative radiation therapy.

Two common techniques are used for partial breast external beam radiation treatment:

Before you have any radiation treatment, you will meet with the radiation oncologist. This person is a doctor who specializes in radiation therapy.

The treatment is usually given 5 days a week for anywhere from 2 to 6 weeks. It may sometimes be given twice a day (usually with 4 to 6 hours between sessions).

Rest assured, you are not radioactive after these radiation treatments. It is safe to be around others, including babies and children.

Why the Procedure Is Performed

APBI is used to prevent breast cancer from coming back. When radiation therapy is given after breast-conserving surgery, it is called adjuvant (additional) radiation therapy.

APBI may be given after lumpectomy or partial mastectomy (called breast-conserving surgery) for:

Before the Procedure

Tell your health care provider what medicines you are taking.

Wear loose fitting clothes to the treatments.

After the Procedure

Radiation therapy can also damage or kill healthy cells. The death of healthy cells can lead to side effects. These side effects depend on the dose of radiation and how often you have the therapy. Radiation can have short-term (acute) or long-term (later) side effects.

Short-term side effects can begin within days or weeks after treatment begins. Most side effects of this type go away within 4 to 6 weeks after treatment ends. Most common short-term effects include:

Long-term side effects may begin months or years after treatment and may include:

Your providers will explain care at home during and after radiation treatment.

Outlook (Prognosis)

Partial breast radiation following breast conservation therapy reduces the risk of cancer coming back, and possibly even death from breast cancer.

Review Date: 7/9/2018
Reviewed By: David Herold, MD, Radiation Oncologist in West Palm Beach, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 10/15/2019. Editorial update 11/19/2019.

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