Phase II study on the use of intraoperative radiotherapy in early breast cancer

OBJECTIVE: To report our early experience using the Intrabeam radiotherapy delivery system for intraoperative radiotherapy (IORT) in early breast cancer.

METHODS: This is a prospective phase 2 study carried out at the Department of Surgery and Radiology, King Abdulaziz University Hospital, Jeddah, Kingdom of Saudi Arabia from December 2010 to November 2012. Females eligible for breast-conserving surgery with biopsy-proven invasive duct carcinoma, and with a mass of </=3.5 cm were included in this study. After wide local excision, sentinel lymph node dissection, and surgically positioning of the appropriately sized applicator on the tumor bed, a 20 Gray (Gy) single dose was prescribed using the Intrabeam x-ray generator. External beam radiotherapy (EBRT; 46 Gy/23 fractions/4.5 weeks) was given when the tumor was >3 cm, with lymphovascular invasion, multifocal lesion, extensive intraductal carcinoma, and positive nodes. Early and late toxicity were recorded using the Radiation Therapy Oncology Group (RTOG) criteria.

RESULTS: Forty-five patients were included with a median age of 54 (range: 27-79 years). Thirty-six cases (80%) had tumor <3 cm in diameter, and 36 (67%) have pathologically negative axillary lymph node metastases. None of the patients developed delayed wound healing, postoperative infection requiring intravenous antibiotic, or breast seroma requiring aspiration. Sixteen (36%) received EBRT after IORT. Twelve patients developed radiologically proved fat necrosis.

CONCLUSION: The IORT for early stage breast cancer patients using the Intrabeam delivery system was easily implemented in our center with an acceptable toxicity profile and cosmetic outcome.