Early clinical results of intraoperative radiation therapy (IORT) during breast conservation using an electronic brachytherapy (EBX) technique.

83 Background: Intraoperative radiation therapy (IORT) as an alternative to whole breast irradiation (WBI) has been described for patients with early-stage breast cancer. The randomized phase III TARGiT trial demonstrated similar recurrence rates to WBI and a lower overall toxicity profile. IORT-related effects and early postoperative outcome were assessed. We report our clinical experience using a 50 Kv EBX HDR radiotherapy delivery system using a balloon technique. We assessed institutional postoperative complications, clinical outcome and histological findings in patients undergoing IORT for breast cancer on a physician sponsored study. Methods: 22 patients (median age 71 years, negative LN and tumor less than 3 cm) underwent lumpectomy, sentinel lymph node (SLN) biopsy, and concurrent IORT from December 2010 to January 2013. 18 were treated on the study and 4 refused enrollment and elected to be treated off protocol. Patients received IORT (20 Gy) during breast conserving surgery using an EBX technique. WBI was added according to clinical guidelines. Cosmetic results and quality of life were evaluated. Results: Postoperative complications and toxicity was rare without grade 3/4 toxicities. The most frequent postoperative side effects were palpable seroma (8.3%). Erythema grade 1-2 of the breast was found in (13%); whereas in some (3.4%), mastitis. In 80% of the cases patient had IFDCA, the remainder DCIS and tumor size ranged between 0.7 and 2.6 cm (median = 1.0cm). At median 1 year follow-up, no patient suffered a local recurrence. Cosmetic outcome was perceived excellent in most patients and 100% would recommend the procedure. One patient required WBI due to close margins at re-excision. No patient had positive SLN on final path. Conclusions: IORT using electronic brachytherapy as part of breast conservation is safe. The potential advantages of IORT are minimal time needed for cellular repopulation between surgery and radiation treatment, cosmetic outcome and significant logistical advantages and reduced cost. Careful surgical assessment minimizes the need for WBI. Longer follow-up will determine clinical results for cosmetic outcome and local control.