The effect of introducing an in-theatre intra-operative specimen radiography (IOSR) system on the management of palpable breast cancer within a single unit.

INTRODUCTION

Intra-operative specimen radiography (IOSR) is used to screen specimens during breast-conserving surgery and attempt to identify incompletely excised lesions. Universal use of IOSR during surgery for impalpable breast cancer is advocated by current guidelines. This study evaluates the role of IOSR during breast-conserving surgery for palpable breast cancer.

METHODS

Two cohorts of patients who underwent wide local excision for palpable breast cancer were identified. Retrospective analysis of histological margins, intra-operative cavity shaves, secondary re-excision rates and specimen weight was completed comparing performance prior to the introduction of IOSR (October 2003-April 2005) with that since its introduction (April 2006-October 2007).

RESULTS

224 Patients were included, 111 in the pre-IOSR cohort (PF) and 113 in the IOSR cohort (F). Patient demographics, tumour size and histology were comparable. No difference in margin involvement prior to intra-operative cavity shaving was noted, PF-26, F-31 (p=0.60). Intra-operative cavity shaves were carried out more frequently in the IOSR group, PF-9, F-32 (p=0.001). When compared with histological findings, IOSR identified margin compromise with sensitivity=58.1%, specificity=80.8%, positive-predictive value=56.25% and negative predictive value=81.9%. Re-operation rate was similar between the 2 groups, PF-26, F-31 (p=0.65). Significantly less tissue was excised following use of IOSR; PF-110g, F-70g (p=0.001).

CONCLUSION

Introduction of IOSR significantly reduced specimen weights without increasing re-excision rates. As volume of breast tissue removed is the most significant determinant of cosmetic outcome following breast-conserving surgery, the use of IOSR should be advocated in the surgical management of palpable breast cancer.