Understanding Accelerated Partial Breast Irradiation

MD Anderson Cancer Center
Date: March 2011


Radiation therapy after breast cancer surgery is an important part of your treatment.  It has been found to lower the risk of cancer returning in the breast.  Traditionally, radiation therapy is given from the outside to the whole breast for 6 to 8 weeks.  A shorter alternative form of radiation therapy is Accelerated Partial Breast Irradiation known as APBI.  This treatment can take as little as 5 days to complete.

Dr. Elizabeth Bloom:

APBI uses brachytherapy which specifically places a radiation source within or next to tissue at most risk for having cancer cells.  Normal, healthy tissues are exposed to less radiation so patients typically experience fewer side effects.


This type of therapy is given to breast cancer patients after lumpectomy surgery.  During a lumpectomy, a surgeon removes your tumor and surrounding breast tissue.  The space that is left after your tumor has been removed is called the lumpectomy cavity.  A catheter or thin tube called a brachytherapy device is inserted through the skin into the lumpectomy cavity. Radiation is then delivered directly to the tissue surrounding the lumpectomy cavity where cancer is most likely to return.  Since radiation is given from within the lumpectomy cavity, your normal healthy tissues are exposed to less radiation. This lessens side effects such as skin discoloration, fatigue, burning and damage to nearby organs.  It is important though for women to understand the research when deciding between traditional whole breast radiation and APBI.

Dr. Elizabeth Bloom:

There's 20 years of research showing that with early stage breast cancer a lumpectomy, followed by whole breast radiation, is as effective as a mastectomy in the local treatment of the breast.  Research also shows that when cancer does return in the breast, it most often returns in the tissues immediately surrounding the lumpectomy cavity.  It only returns away from the lumpectomy cavity 1 to 4 percent of the time.  And this is the same whether or not patients receive whole breast radiation. 

In other words whole breast radiation has not been shown to provide additional protection against cancer developing or returning in other parts of the breast.  APBI targets the breast tissue immediately surrounding the lumpectomy cavity which reduces the amount of radiation to the rest of the breast.  Studies have shown that the rate of cancer returning within the breast is in general less than 5 percent.  But there has only been 5 to 10 years of follow up data.

Brachytherapy Catheter Placement


If you are a candidate for brachytherapy, your doctor will decide which brachytherapy device will work best for you based on your breast size and the location, size and shape of your lumpectomy cavity.  There are two methods of placing the brachytherapy device within your breast, two-stage placement and one-stage placement.  Your surgeon and radiation oncologist will work together to plan your treatment and decide if two-stage or one-stage placement is best for you. 

With two-stage placement, your surgeon places a temporary spacer within the lumpectomy cavity during your breast surgery.  With one-stage placement, a temporary spacer is not placed during your breast surgery.  A few days after your breast surgery, you will meet with the radiation oncologist.  You will have a CT scan for the doctor to assess your lumpectomy cavity and determine the best brachytherapy device to use for treatment. 

Next, you will have your postoperative appointment with your surgeon.  At that time your surgeon will place the brachytherapy device in your breast.  If you had two-stage placement, the temporary spacer is replaced with the appropriate brachytherapy device.  To do this, the skin of your breast and your lumpectomy cavity will be numbed using a local anesthetic.  The spacer is removed and the new device is placed through the same entry into your lumpectomy cavity. 

If you had one-stage placement, there is no temporary spacer to remove.  Your surgeon will numb the skin of your breast and your lumpectomy cavity with a local anesthetic.  A small incision will be made in the breast to allow the appropriate brachytherapy device to go through the opening into the lumpectomy cavity. 

The placement of the device is relatively painless for both methods because you are given a local anesthetic and medicine the morning of your appointment to help you relax.  You will be awake and able to talk during the procedure.

Brachytherapy Treatment Plan


Once the appropriate brachytherapy device is placed in your breast, you will have a treatment planning appointment scheduled one to three days later.  During this appointment, a CT will be performed to help your radiation oncologist plan your treatment. 

Brachytherapy Treatment


Radiation treatment begins the next day and is given twice a day, 6 hours or more apart for 5 working days.  During each treatment the portion of the catheter that remains outside your breast is connected to a machine.  This machine puts a radioactive pellet into the catheter.  The pellet travels down the catheter inside the lumpectomy cavity to deliver radiation.  Each treatment takes about 10 to 20 minutes.  When the radiation treatment session is finished, the pellet is withdrawn back into the machine and the catheter is disconnected.  No radiation remains inside your breast in between treatments.  After all the treatment sessions are complete, the brachytherapy device will be removed. 

If you have any questions about Accelerated Partial Breast Irradiation please ask your doctor or nurse.


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