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:
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.
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.
Your care team is led by your radiation oncologist, and may include a physicist, dosimetrist, nurse, and radiation therapists. Our radiation oncologists performing APBI have undergone specialized training in this technique.
Radiation Oncologists Performing APBI:
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.
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.
Your surgeon and radiation oncologist will assess your eligibility for APBI. Eligibility criteria include both clinical patient factors and pathologic characteristics of your breast cancer. In general, candidates have a single focus of breast cancer with negative margins. The American Society of Radiation Oncology (ASTRO), American Society of Breast Surgeons (ASBS), American College of Radiation Oncology (ACR), and American Brachytherapy Society (ABS) have all published guidelines on patient selection criteria for APBI. These recommendations, along with other clinical data, are used in our treatment decision making process.
Radiation sterilizes any cancer cells which may be left behind after surgery. While a surgeon removes all visible tumor, clinical trials have shown that after lumpectomy, up to four out of 10 women may have breast cancer grow back in the same breast. The addition of radiation thus takes the place of a mastectomy. Instead of physically removing all the breast tissue, we treat it to minimize the risk of same breast cancer recurrence. This combined approach has been shown to have equivalent overall survival and breast cancer survival compared to mastectomy.
For appropriately selected patients with early breast cancers, outcomes have been similar to adjuvant whole breast radiation. A large trial of over 1,400 appropriately selected patients treated with Mammosite reported a five-year local recurrence rate of 3.8%, which is similar to what would be anticipated with whole breast radiation.
Side effects during and around time of radiation include, but are not limited to:
- Mild discomfort at catheter site
- Drainage from catheter site
- Breast soreness/swelling
- Sunburn-like skin reaction over treated area
- Low risk of infection
Over the long term, side effects could include but are not limited to:
- Changes in skin pigmentation
- Soft tissue texture and appearance
- Prolonged fluid in lumpectomy bed in ~ 1/3 of patients (seroma)
- Injury of the surrounding tissues.
No. Your exposure is limited to the twice-daily radiation treatments in our office. You are not radioactive when you leave our department.
We starting treating patients with APBI technique in 2004.
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:
- Radiation Therapy Answers - www.rtanswers.org
- American Cancer Society - www.cancer.org
- National Cancer Institute (at the National Institutes of Health) - www.cancer.gov
- American Society for Clinical Oncology – www.cancer.net
Below are several links from the manufacturers of SAVI, Contura, and MammoSite: