Figure 2From: Sentinel lymph node biopsy for breast cancer using methylene blue dye manifests a short learning curve among experienced surgeons: a prospective tabular cumulative sum (CUSUM) analysis Hypothetical CUSUM plot for surgeon/trainee failing to identify 1 st , 6 th and 12 th SLN. Parameters are from Table 3. Plot crosses SPRT limit line after 22 cases.Back to article page