Intraoperative Electron Radiotherapy Boost as a Component of Adjuvant Radiation for Breast Cancer in the Community Setting

Abstract

To reduce toxicity/treatment time and improve accuracy, intraoperative electron radiotherapy (IOERT) was used as an alternative to electron beam radiation therapy boost. Primary objective was to determine feasibility and acute toxicity. From August 2009 to June 2011, 50 patients (age 32 to 76 years) with in situ or invasive breast cancer (Stage 0 to IIIA) were treated. Toxicity assessed according to standard National Cancer Institute scales. Median tumor size was 20 mm (range, 6 to 80 mm) with 43 infiltrating ductal, two infiltrating lobular, and five ductal in situ carcinoma. A single 10-Gy fraction boost was given to the tumor bed after resection followed by whole-breast radiotherapy. After IOERT, three patients required completion axillary lymph node dissection, eight had reexcision resulting from positive margins, and four opted for completion mastectomy. The median follow-up was 10 months (range, 2 to 24 months). Ten patients had Grade 1 and one reported Grade 2 breast pain 2 weeks after IOERT; all resolved at 6 weeks. Two patients had delay in wound healing, but none developed a wound infection. Three patients reported symptomatic fat necrosis. No other toxicities were reported. IOERT resulted in a reduction in treatment time, was not associated with additional toxicity or change in the acute toxicity profile, and is a feasible treatment option in a community hospital setting.