The American Society for Radiation Oncology (ASTRO) has issued an updated clinical practice statement for accelerated partial breast irradiation (APBI) for early stage breast cancer. The updated guideline reflects recent evidence that greater numbers of patients can benefit from accelerated treatment and also provides direction for the use of intraoperative radiation therapy (IORT) for partial breast irradiation. The update to the 2009 ASTRO consensus statement for APBI is available as a free access article in Practical Radiation Oncology, ASTRO’s clinical practice journal.
Early stage breast cancer patients often receive radiation therapy (RT) following breast-conserving surgery to lower the chance of recurrence or metastasis, generally in the form of whole-breast irradiation (WBI) using external-beam radiation delivered over several weeks. APBI is a newer, localized alternative that delivers the effective radiation dose directly to the tissue at risk. This targeted therapy reduces treatment time and may limit adverse side effects, particularly those involving the heart and lungs. More than 75,000 women in the United States have received APBI since its introduction in the late 1990s.
Drawing on evidence published in the last eight years, the guideline suggests that more breast cancer patients can benefit from APBI, including younger patients and those with low-risk ductal carcinoma in situ (DCIS). The guideline suggests that more breast cancer patients can benefit from APBI, including younger patients and those with low-risk ductal carcinoma in situ (DCIS). The guideline recommends considering the following factors for the use of APBI outside of clinical trial settings:
The update also provides guidance for the use of intraoperative RT for early stage breast cancer patients, drawing on two large, phase III clinical trials that compared WBI with IORT. Partial breast irradiation may be administered in a variety of methods, including brachytherapy, external beam RT and IORT, a single-dose radiation treatment commonly delivered at the time of surgery using either an electron beam or low-energy X-rays. Recommendations for the use of IORT include:
“As trials mature and evidence accumulates, we can understand more comprehensively who benefits from accelerated radiation treatment following lumpectomy, and we are finding that the pool of suitable candidates for this emerging treatment is larger than first anticipated,” said Jay R. Harris, MD, FASTRO, chair of the task force that developed the guideline and distinguished professor of radiation oncology at the Dana-Farber Cancer Institute, Harvard Medical School in Boston. “Carefully selected patients may achieve similar tumor control following shorter, targeted schedules of radiation as they would with weeks of radiation to the whole breast.”
Electron beam IORT should be restricted to patients with invasive cancer who are also considered suitable for partial breast irradiation, based on data from a trial with 5.8-year median follow-up.
The guideline was based on a systematic literature review of studies published since May 2008, the last date searched for the original clinical practice statement. A total of 419 abstracts were retrieved from PubMed, and the 44 articles that met inclusion criteria were abstracted into evidence tables and evaluated by an eight-member task force of radiation oncologists, medical oncologists and experts in IORT. The clinical practice statement was approved by ASTRO’s Board of Directors following a four-week period of public comment.
ASTRO develops evidence-based guidelines to provide physicians with guidance to help patients receive the best possible care. To date, ASTRO has completed 17 clinical practice statements across multiple disease sites.Back To Top
Updated ASTRO guideline expands pool of suitable candidates for accelerated partial breast irradiation. Appl Rad Oncol.