Dr. D'Ambrosio on the Rationale of Accelerated Partial Breast Irradiation in HR+ Breast Cancer

David D'Ambrosio, MD, a radiation oncologist, the Medical Director, New Jersey CyberKnife, RWJBarnabas Health, discusses the benefit of utilizing adjuvant accelerated partial breast irradiation, as well as a phase 2 trial investigating robotic stereotactic adjuvant accelerated partial breast irradiation for hormone receptor (HR)–positive, postmenopausal, early-stage breast cancer.

In appropriately selected patients, accelerated partial breast radiation has shown less toxicity, compared with traditional approaches to radiation, D'Ambrosio begins. Moreover, accelerated partial breast radiation has also shown good local control rates, translating lower rates of recurrence, D'Ambrosio notes. Historically, accelerated partial breast radiation has been delivered to the appropriate patients with either standard external radiation or with brachytherapy, the latter of which is the use of source radiation to give radiation to the lumpectomy cavity, D'Ambrosio explains.

Investigators of a prospective phase 2 trial (NCT02365714) presented data on 2-year outcomes on patients with HR-positive early-stage breast cancer treated with robotic stereotactic accelerated partial breast irradiation at the 2022 San Antonio Breast Cancer Symposium. The trial aimed to show that there was no detriment in control rates and both feasible and acceptable toxicity with this approach for early-stage breast cancer, D'Ambrosio continues.

The study enrolled 81 patients, and at a median follow-up of 2 years, findings showed that only 1 woman had a new ipsilateral breast tumor diagnosed, D'Ambrosio explains. Moreover, there were no significant grade 3 limiting toxicities, showing that this method was feasible and safe, D'Ambrosio concludes.