The Role of Intraoperative Radiation in Early-stage Breast Cancer

Intraoperative radiation therapy (IORT) is a specialized form of accelerated partial breast irradiation in which a single dose of radiation is delivered to the tumor bed at the time of breast conserving surgery. With completion of radiation to the tumor bed at the time of surgery, IORT promises improved patient convenience, compliance, and quality of life. In addition, with its potentially skin-sparing properties and ability to deliver a high biologically effective dose to the tumor bed while reducing dose to nontarget tissues, IORT results in different but overall less toxicities compared with other modalities of radiation for breast cancer. However, skepticism over the role of IORT in breast cancer exists, and the 2 randomized trials that have analyzed IORT as the definitive radiation component of breast conservation therapy have shown an increase in local recurrence rates with IORT compared with whole breast irradiation, but similar rates of overall survival. In this review, we discuss the practicalities of IORT, the prospective data supporting and negating the role of IORT in lieu of whole breast irradiation, and the toxicity after IORT in early-stage breast cancer. We also review the role of IORT as a radiation boost and specific strategies for successful implementation of IORT in breast cancer.