Intra-operative assessment of excised breast tumour margins using ClearEdge imaging device

Abstract

IntroductionBreast conserving surgery (BCS) aims to remove a breast cancer completely and obtain clear margins. Complete excision is essential to reduce the risk of local recurrence. The ClearEdge™ (CE) imaging device examines margins of excised breast tissue intra-operatively. The aim of this study was to investigate the potential of the device in detecting margin involvement in patients having BCS. MethodsIn Phase-1 58 patients underwent BCS and had 334 margins assessed by the device. In Phase-2 the device was used in 63 patients having BCS and 335 margins were assessed. Patients with margins considered close or involved by the CE device were re-excised. ResultsThe margin assessment accuracies in Phase-1 and Phase-2 compared to permanent section pathology were very similar: sensitivity (84.3% and 87.3%), specificity (81.9% and 75.6%), positive predictive value (67.2% and 63.6%), and negative predictive value (92.2% and 92.4%). The false positive rate (18.1% and 24.4%) and false negative rate (15.7% and 12.7%) were low in both phases. In Phase-2 re-excision rate was 37%, but in the 54 where the CE device was used appropriately the re-excision rate was 17%. Had all surgeons interpreted all images appropriately and re-excised margins detected as abnormal by the device in Phase-2 then the re-excision rate would have been 7%. ConclusionThis study shows that the CE device has potential to reduce re-excision after BCS and further randomized studies of its value are warranted.