Early clinical experience with Xoft’s Axxent electronic brachytherapy system demonstrated that the x-ray-based, non-isotopic treatment is a viable option for adjuvant therapy for early-stage breast cancer, according to initial data from a multi-center study presented last week at the 2008 American Society of Clinical Oncology (ASCO) Breast Cancer Symposium in Washington, D.C.
The phase IV study, “Early experience with an electronic brachytherapy technique for intracavitary accelerated partial breast irradiation,” presented in poster discussion by Vivek Mehta, MD, director of the Center for Advanced Targeted Radiotherapies at Swedish Cancer Center in Seattle, was designed to evaluate the safety and device performance of electronic brachytherapy treatment using the Axxent system for early stage breast cancer.
“While we will be monitoring these patients for the next five years, this data is very exciting as it confirms what we as investigators hoped it would from the start – that electronic brachytherapy is a safe and clinically promising alternative for accelerated partial breast irradiation,” said Mehta, radiation oncology principal investigator for the study.
The study, which began enrolling in April 2007, was performed at 10 clinical sites across the United States. Eligible patients received an accelerated course of radiation treatment delivering 3.4 Gy/fraction twice a day for five days. The primary endpoint of the study was the successful delivery of the prescribed radiation therapy and the secondary endpoint was the collection of adverse device related events, the researchers said.
“The electronic brachytherapy treatment also focuses the delivery of radiation on a small area within the breast which allows the treatment to be completed in one week instead of the conventional treatment which lasts seven weeks,” added Mehta.
Interim results presented at the symposium on 38 patients who completed treatment showed that 25 of these patients were followed for a minimum of one month post-treatment. In this group, the electronic brachytherapy treatment was successfully delivered in every patient for every fraction. The side effects of treatment reported were generally mild, manageable and expected, reported the authors.
In its treatment of early stage breast cancer, Xoft said that Axxent provides the opportunity to reduce the therapy time required from seven weeks (for external radiation therapy) down to five days. This may accelerate patient choice of breast sparing lumpectomy surgery with adjuvant radiation therapy over the alternative of a full mastectomy.