Accelerated Partial Breast Irradiation

Publication Date: June 5, 2018
Last Updated: March 14, 2022


Recommendations are limited by the data available at the time this document was written. At this time, the long-term results from the NSABP B-39 study are not published.

Patients should be carefully selected for accelerated partial breast irradiation (APBI) and properly informed of the current benefits and risks when considering APBI, whole breast irradiation (WBI), and no radiation. There are several APBI options that exist. There are risks and benefits to each of these approaches concerning effectiveness, side effect profile, patient access, and patient preference. These relevant techniques include:
  1. External beam radiation therapy (EBRT) with 3-D conformal radiation, intensity modulated radiation therapy (IMRT) or protons
  2. Brachytherapy with intercavitary or interstitial techniques
  3. Intraoperative radiation therapy IORT.

The American Society of Breast Surgeons recommends the following selection criteria when considering patients for treatment with APBI:
Age: Minimum of 45 years
1. Histology: All invasive subtypes
Ductal carcinoma in situ (DCIS)
2. Total tumor size (invasive and DCIS): less than or equal to 3 cm in size
3. T Size: Tis, T1, T2 (≤3 cm)
4. Margins: No tumor on ink for invasive tumors and invasive tumors with associated DCIS
≥ 2mm for DCIS
Note for patients treated with IORT with unknown margins status: If margins are found to be positive after IORT treatment, patient should be recommended to undergo re-excision. If re-excision margin is acceptable, WBI should be considered and discussed with multidisciplinary tram and the patient. If WBI is administered after IORT, the IORT dose can be substituted for the boost dose.
5. Nodal Status: Negative
Note for patients treated with IORT and subsequently found to have a positive SLN: WBI should be considered. If WBI is administered, the IORT dose can be substituted for the boost dose.
6. Other Factors: Multifocal disease is allowed as long as the combined area of tumor is ≤3cm.
  • Tumor may be estrogen receptor positive or estrogen receptor negative.
  • Lymphovascular invasion is allowed as long as it is focal.
  • Patients should not be treated with APBI if they have a BRCA genetic mutation or other genetic mutation that confers an increased risk of breast cancer.
  • There is no evidence to support use of APBI in male patients.
  • Patients with a history of ipsilateral breast cancer treated with radiation should only be treated with APBI as part of specific clinical trial.
  • No contraindication to APBI in patients with history of contralateral breast cancer.
7. Patient selection and counseling should be performed in a multidisciplinary fashion with collaboration between the treating surgeon and the treating radiation oncologist.
8. It is preferred that all patients treated are part of a clinical trial or registry. All patients should be monitored regularly to identify adverse events as well as local recurrences.
9. The published data for APBI supports the recommendations summarized above. Continuous, long-term, outcomes-based monitoring of APBI is desirable. The American Society of Breast Surgeons maintains an ongoing MammosSite® Registry (registration completed in 2004), collecting data on 1440 patients treated via the MammosSite® balloon catheter technique.
10. These recommendations are intended as a guide to treat patients. Individual treatment decisions could allow treatment outside of the parameters listed above with appropriate discussion with the patient.

Recommendation Grading




Accelerated Partial Breast Irradiation

Authoring Organization

Publication Month/Year

June 5, 2018

Last Updated Month/Year

August 7, 2023

Document Type


External Publication Status


Country of Publication


Document Objectives

To outline the use of accelerated partial breast irradiation (APBI) for the treatment of breast cancer.

Inclusion Criteria

Female, Adult, Older adult

Health Care Settings

Hospital, Operating and recovery room, Outpatient

Intended Users

Radiology technologist, clinical researcher, nurse, nurse practitioner, physician, physician assistant


Management, Treatment

Diseases/Conditions (MeSH)

D001943 - Breast Neoplasms


breast cancer, Breast Cancer, Accelerated Partial Breast Irradiation, breast cancer management