Twelve-month follow-up results of a trial utilizing Axxent electronic brachytherapy to deliver intraoperative radiation therapy for early-stage breast cancer.

Background: Accelerated partial breast irradiation (APBI) is emerging as a valid alternative to whole-breast radiation therapy (WBRT) in breast-conserving therapy (BCT) for early-stage breast cancer. Axxent electronic brachytherapy (EBX) is a form of portable, balloon-based APBI that utilizes an electronic source of kilovoltage irradiation delivery with minimal shielding requirements. As such, EBX becomes a logical and convenient modality for delivery of intraoperative radiation therapy (IORT). We report 1-year results and clinical outcomes of a trial that utilizes EBX to deliver IORT for patients with early-stage breast cancer.

Methods: Eleven patients were enrolled on an institutional review board (IRB)-approved protocol. Inclusion criteria were patient age >45 years, unifocal tumors with infiltrating ductal or ductal carcinoma in situ (DCIS) histology, tumors ≤3 cm, and uninvolved lymph nodes. Preloaded radiation plans were used to deliver radiation prescription dose of 20 Gy to the balloon surface.

Results: The mean time for radiation delivery was 22 min; the total mean procedure time was 1 h 39 min. All margins of excision were negative on final pathology. At mean follow-up of 12 months, overall cosmesis was excellent in 10 of 11 patients. No infection, fat necrosis, desquamation, rib fracture or cancer recurrence has been observed. There was no evidence of fibrosis at last follow-up.

Conclusion: IORT utilizing EBX is emerging as a feasible, well-tolerated alternative to postsurgical APBI. Further research and longer follow-up data on EBX and other IORT methods are needed to establish the clinical efficacy and safety of this treatment.