Learning curves in intraoperative ultrasound guided surgery in breast cancer based on complete breast cancer excision and no need for second surgeries

Abstract

Background: Intraoperative ultrasound guided surgery (IOUS) is an effective surgical technique for breast cancer with advantages over wire localization guided surgery (WL), enabling smaller lumpectomies without compromising margins. Nevertheless, it has had a slow implementation, maybe due to lacking a learning curve. Also differences in costs are not clearly reported. The aim of the study is to assess differences in volume of healthy breast tissue excised, to establish a learning curve and to prove it is cost saving.

Patients and methods: From February 2009 to April 2013, women diagnosed with invasive breast cancer eligible for IOUS or WL breast conserving surgery were recorded into a prospectively maintained database. Both groups were compared for differences in margin status, second surgeries and excess of healthy tissue resected, defined by the calculated resection ratio (CRR). A raw cost study was assessed. IOUS learning curve was analyzed using Cumulative sum control chart (CUSUM).

Results: The study included 214 patients, 148 (69.16%) in the IOUS group and 66 (30.84%) in the WL group. IOUS showed significantly smaller surgical volumes (p = 0.02), smaller CRR (p = 0.006), higher rate of negative margins (p = 0.017) and less surgical time (p = 0.006) than WL. Learning curves based on complete tumor excision and no need for second surgeries showed that 11 cases were enough to master the technique. Around 900€ per surgery was saved using IOUS vs. WL.

Conclusion: IOUS decreases excision of healthy breast tissue while increasing negative margin rates compared to WL. IOUS can be easily implemented; 11 cases are enough to acquire skills for performing the technique. Savings can be up to 900€ per surgery.

Keywords: Breast cancer; Cost study; Learning curve; Margins; Ultrasound guided surgery; Wire localization.