Background: This study was performed to determine if surgeons' performance of sentinel lymph node biopsy (SLNB) for breast cancer varied with time and to devise a method to continuously evaluate that performance.
Methods: We retrospectively examined the SLNB experience of 13 community surgeons performing 765 SLNBs and 579 concomitant axillary dissections. False-negative rates (FNRs) were assessed for individuals and cohorts defined by caseload. Performance with time was assessed using cumulative sum (CUSUM) analysis.
Results: Overall, the SLN identification rate was 94.3%, and FNR was 5.3%. Each surgeon demonstrated variation in identification rate and/or FNR with time. CUSUM analysis provided an effective means to demonstrate when surgeon variation breached performance standards.
Conclusions: Surgeon performance of SLNB varied with time, independent of case load. CUSUM may prove to be a useful statistical tool to evaluate performance before adopting stand-alone SLNB.