The impact of intra-operative specimen radiographs on specimen weights for wide local excision of breast cancer

Abstract

The ultimate goal of breast conserving surgery (BCS) is to achieve survival and local control rates similar to those for mastectomy while providing improved cosmetic and functional results. The volume of breast tissue removed is the most significant determinant of the final cosmetic outcome of BCS. We hypothesised that intra-operative specimen radiograph (IOSR) during BCS may guide the surgeon to achieve clear radiographic and histological margins with minimum normal breast tissue excision, thus preserving cosmetic appearance. The aim of this study was to evaluate the effect of introducing the policy of IOSR on the weight of specimens of wide local excision of palpable invasive breast cancer. All consecutive patients who underwent therapeutic wide local excision for palpable invasive breast cancer from 01/01/02 to 31/03/03 were included in this study. A policy of IOSR was introduced in October 2002, thus all BCS done after 01/10/2002 underwent IOSR. The mean (S.D.) specimen weight for the no intra-operative specimen radiograph (NIOSR) group was 74 grams compared to 46 g in the IOSR group, ( P=0.0241, unpaired t-test with Welch's correction) and the mean tumour size for the NIOSR was 23(13) mm and for IOSR was 21(8) mm ( P=ns, unpaired t-test with Welch's correction). A histologically clear circumferential margin rate in the IOSR group was 96% compared to 82% in the NIOSR group. Five patients in the IOSR group and 11 in NIOSR group had positive anterior or posterior margin. For these patients no further surgical excision was possible as BCS was performed from skin to pectoral fascia. Therefore a radiation boost was given to the site of excision. Only one patient in the IOSR group needed further breast surgery (mastectomy) for a positive inferior (toward nipple) margin for a mammographically occult tumour, while 11 patients in the NIOSR group required further breast surgery. In conclusion, IOSR is a simple, effective and economical way of assessing adequacy of margins while minimising the breast tissue excised during wide local excision of palpable breast cancers.