The American Society for Radiation Oncology has issued new guidelines recommending accelerated partial breast irradiation brachytherapy (APBI) as an alternative to whole breast irradiation (WBI) after surgery in early-stage breast cancer patients, and lowering the age range of patients considered suitable for the procedure to people 50 and older, from 60.
With APBI, localized radiation is delivered to the region around the excised tissue, reducing treatment time and sparing healthy tissue. APBI may also be considered for patients 40 and older, according to ASTRO, if they meet all of the pathologic criteria for suitability listed in the guidelines for patients 50 and above.
The guidelines represent the first ASTRO update on APBI since 2009. In addition to expanding the age range for APBI treatment, the guidelines add low-risk ductal carcinoma in situ as an indication. The guidelines also address intraoperative radiation therapy, or IORT, in which patients receive low-energy photon or electron radiation during surgery (Pract Rad Oncol. 2016 Nov. 17 doi: 10.1016/j.prro.2016.09.007).
While IORT is suitable for patients with invasive cancer eligible for APBI, the guidelines say, patients considering this option should be counseled about the risk of recurrence compared with standard treatment, and, with photon IORT, about potential toxicity risk requiring follow-up. Though more than 40 studies were considered by the ASTRO committee, including large randomized trials comparing APBI with WBI, the new recommendations represent “more of a tweak than a revolution,” said Jay Harris, MD, of Brigham and Women’s Hospital and Dana-Farber Cancer Institute, Boston, one of the guideline authors.
Dr. Harris noted in an interview that two important randomized controlled trials comparing APBI and WBI are still underway, with full follow-up results expected in 2-3 years, after which more definitive recommendations can be made. For the intraoperative radiation advice contained in the guidelines, “we had evidence from two trials looking at different approaches,” Dr. Harris said. “One has long-term data using an electron beam in the operating room – this group showed that that approach seems reasonable in patients that we at ASTRO considered suitable in general for APBI. The other approach is low-dose photon radiation, for which we have only short-term follow-up, making us more hesitant to endorse it.” As for the new recommendation sanctioning APBI for ductal carcinoma, “There’s a lot of variation [in protocols] across the country, compared with invasive cancer,” Dr. Harris said. “We’re kind of all over the map with DCIS. This guideline presents another option.”
The guidelines were sponsored by ASTRO; two authors disclosed financial relationships with firms that make radiologic technology.