Achieving clear margins. Directed shaving using MarginProbe, as compared to a full cavity shave approach

Abstract

Background Following lumpectomy, full cavity shaving approach is used to reduce positive margin rates, among other issues previously studied by others, at an expense of increase in tissue volume removed. We present our experience after switching from full cavity shaving to a targeted shaving approach using MarginProbe, an intra-operative margin assessment device. Methods Specimen excision was performed according to standard of care. Additional shavings were taken based on device readings on the lumpectomy specimen. Intra-operative imaging was used, as required. Results We compared 137 MarginProbe cases to 199 full cavity shave cases. The re-excision rate was reduced by 57% (P = 0.026), from 15.1% to 6.6%. The overall tissue volume removed was reduced by 32% (P = 0.0023), from 115 cc to 78 cc. Conclusions MarginProbe enabled a change in the lumpectomy technique from full cavity shavings to directed shavings guided by the device. There was a significant reduction in re-excisions and in the overall tissue volume removed.The lower amount of shavings also contributed to a reduction in pathology work.