Accelerated Partial Breast Irradiation (APBI)

Accelerated Partial Breast Irradiation (APBI) is a technique that may be used in the treatment process of breast cancer. APBI delivers radiation therapy to the cavity in the breast after a cancerous tumor is surgically removed.

There are two different types of APBI:

  1. Brachytherapy is the delivery of radiation via an internal source. For breast brachytherapy, this involves placing either a balloon or catheters (flexible plastic tubes) into the breast cavity where the tumor was removed. During treatments, a radioactive source the size of a grain of rice is inserted into the balloon or catheters. The treatment time is about five to fifteen minutes and the patient does not feel any side effects during treatment, as the radioactive source is within the balloon or catheters during this time. We offer SAVI (Strut Adjusted Volume Implant), Contura, and MammoSite Breast Brachytherapy.
  2. External beam radiation is delivered similarly to whole-breast radiation. A linear accelerator is used to focus a beam of radiation on the area around the lumpectomy site.

Who is eligible for APBI?

In general, APBI is appropriate for patients who are older than 50, have a small tumor (<3cm) which has been completely excised from the breast, and does not have involvement of regional lymph nodes. Your radiation oncologist will assist you in choosing the best type of radiation treatment for your situation.

Benefits of APBI

  • Treatment regimens are shorter: APBI allows the patient to complete their course of radiation treatment in just five days (with twice-daily treatments)—a much shorter course than the typical three to six-week treatment seen with whole breast irradiation (WBI) for breast cancer.
  • More breast tissue is spared from radiation exposure: Because radiation is delivered directly to the lumpectomy site and can be customized to the individual patient, less of the surrounding tissue is exposed to radiation.

What to Expect

Your board-certified Radiation Oncologist at The Oregon Clinic will help you decide if APBI is a viable option for you by reviewing your current diagnosis, past treatments, physiology, and other medical factors. If you and your Radiation Oncologist decide to pursue APBI, your Radiation Oncologist will create a customized treatment plan to deliver radiation to the areas that need it most, while protecting surrounding tissue and organs if you meet all the criteria for treatment.

Placement of Breast Brachytherapy Applicators

Your Radiation Oncologist will explain the process of inserting the catheters or balloon into your breast cavity.

  • MammoSite or Contura involves the temporary placement of a balloon catheter in the lumpectomy cavity through a small incision in the breast. The balloon is “inflated” with saline so that it fits inside the cavity, and remains inflated during the five-day treatment. A small portion of the catheter remains outside of the breast for radiation delivery, and is secured comfortably to prevent movement.
  • The SAVI applicator involves the temporary placement of a bundle of catheters to the lumpectomy cavity through a small incision in the breast. The catheters are expanded to fit inside the cavity, while a small section of the applicator remains outside the breast for radiation delivery. This catheter will remain in your breast throughout the five-day treatment. The end of the catheter is secured comfortably to prevent movement.

Radiation Delivery

For both MammoSite and SAVI, the ends of the catheters are connected to a computer-controlled High Dose Rate (HDR) machine. The machine painlessly delivers a tiny radioactive “seed” into the applicator or balloon. After treatment is complete (about ten minutes per treatment), the “seed” is completely removed. No radiation remains in the patient’s body between treatments. After the last treatment, the physician removes the device through the same small incision in which it was inserted.


Understanding the implications of a diagnosis of cancer or the many available treatment options can be overwhelming and frightening. The list of excellent third-party websites below provide comprehensive and clear, unbiased information regarding a variety of cancers and treatment options. Please feel free to discuss any information you learn online with your physician:

Learn more about Radiation Oncology at The Oregon Clinic