Margin assessment before intraoperative radiotherapy during breast conserving surgery—Does the addition of MarginProbe decrease the need for addition of fractionated whole breast radiation?

When performing Breast Conserving Surgery (BCS) with Intraoperative Radiation Therapy (IORT), positive resection margin necessitates not only re-lumpectomy—but also the addition of fractionated whole breast radiation. This retrospective study of 106 patients undergoing BCS and IORT aims to evaluate intraoperative margin assessment use in our center, and the contribution of the MarginProbe device (MP) to achieving negative surgical margins. Eleven out of 106 lumpectomy specimens had a total of 17 margins positive for tumor cells. Intraoperative gross pathology identified 6 (43%) involved margins, MarginProbe detected 8 (50%), and their combined use allowed for detection of 12 (70.5%) involved margins. In conclusion, the adjunctive use of intraoperative gross pathology and MarginProbe reduced the number of lumpectomies with positive resection margins by more than 50%, decreasing the need for re-lumpectomy and the addition of whole breast radiation.