Objective: The purpose of this study was to compare outcomes of radioactive seed localization (RSL) versus wire localization using surgical margin size, reexcision and reoperation rates, specimen size, radiology resource utilization, and cosmesis as measures.
Materials and methods: Patients who underwent RSL before segmental mastectomy from April 1, 2011, to March 1, 2012, for biopsy-proven cancer were selected. Each was matched using tumor size, type, and surgeon to a wire localization control case, resulting in 232 cases. Width of the closest surgical margin, reexcision rate, and reoperation rate were compared as were the ratios of tumor volume to initial surgical specimen volume and tumor volume to all surgically excised volume (including reexcisions and reoperations). Cosmetic outcome was analyzed by comparison of Harvard scores and specimen volume with breast volume. Radiology resource utilization was compared before and after RSL implementation.
Results: No significant differences between methods were found in closest surgical margin (RSL mean, 0.45 cm; wire localization mean, 0.45 cm; p=0.972), reexcision rate (RSL mean, 21.1%; wire localization mean, 26.3%; p=0.360), reoperation rate (RSL, 11.4%; wire localization, 12.7%; p=0.841), ratio of the tumor volume to initial surgical specimen volume (RSL mean, 0.027; wire localization mean, 0.028; p=0.886), ratio of the tumor volume to total volume resected (RSL mean, 0.024; wire localization mean, 0.024; p=0.997), or in clinical or computed cosmesis scores (clinical p=0.5; calculated p=0.060). There was a 34% increase in scheduled biopsy slot utilization, 50% savings in time spent scheduling, and a 4.1-day average decrease in biopsy wait time after RSL institution.
Conclusion: RSL is an acceptable alternative to wire localization and offers significant improvements in workflow.
Keywords: localization; lumpectomy; seed; surgical margins; wire.