Experts have published updated guidelines for the appropriate and safe use of accelerated partial-breast irradiation (APBI) in the treatment of breast cancer.
The study with the guidelines, “The American Brachytherapy Society consensus statement for accelerated partial-breast irradiation,” was published in the journal Brachytherapy.
Patients with ductal carcinoma in situ (DCIS) and early-stage invasive breast cancer first undergo breast-conserving surgery and then adjuvant radiation.
APBI, a targeted therapy, is an alternative to the standard whole-breast irradiation, delivered through brachytherapy or through external radiation to the specific part of the breast from where the tumor was extracted. With this method, the entire breast does not undergo radiation, and the time a patient undergoes radiation therapy is reduced. Also, less healthy tissue is targeted, and the method has fewer side effects.
Chirag Shah, MD, and a group of doctors appointed by the American Brachytherapy Society developed a set of APBI guidelines based on recent data to provide clinicians recommendations for selecting which patients to treat with APBI and the different techniques that can be used. The guidelines are based on extensive research of both literature and clinical experience.
Among the updates, younger patients are now allowed to undergo this procedure, along with DCIS patients. This significantly expands the number of people eligible for the therapy.
Experts now recommend that patients undergoing APBI should be 45 years of age or older, diagnosed with invasive breast cancer and ductal carcinoma in situ, and tumors must be 3 cm or less. Additionally, the tumor must not have spread to the lymph nodes or the lymphovascular space, and the patient should have negative margins.
“The updated guidelines support clinicians by offering them the ability to appropriately select patients for APBI, and data that supports the techniques,” Shah said in a press release. “Guidelines allow for the selection of patients who can finish radiation treatment in one week or less, compared to the traditional period of three to six weeks, and potentially a reduction in side effects depending on the APBI technique.”
Regarding APBI techniques, researchers strongly recommend the interstitial brachytherapy APBI, where devices containing radioactive material are inserted directly into the tumor site, and intensity-modulated radiation therapy APBI, a type of conformal radiotherapy that shapes the radiation beams to fit the area of cancer.
Experts moderately recommend applicator brachytherapy, which are single-entry devices including balloon and strut devices that deliver radiotherapy during surgery and are removed afterward. They also moderately recommend three-dimensional conformal radiotherapy APBI.
The authors do not recommend intraoperative radiation therapy, which delivers a concentrated dose of radiation therapy during surgery and in a single session, and electronic brachytherapy, where a small, high-dose X-ray source is used to apply radiation directly into the cancer site.
Shah also led the development of previous APBI guidelines in 2013. Since then, multiple clinical trials have evaluated the use of APBI.