Statistical Analysis
A Simon's two-stage design was used.ICG use would be justified if, after NIR visualization, an additional lymph node was removed; its use would be further justified if the additional lymph node was metastatic;ICG use would not be justified if no additional lymph-nodes after NIR visualization were removed;ICG use would have a potentially negative effect if after NIR visualization a tissue with no lymph nodes was harvested.According to these assumptions, the utility/futility of the procedure was quantified with the values shown in Table In stage I, if less than two patients had a positive response, the intervention would be considered futile, and the study would be stopped.In stage II, an additional ten patients would be accrued. If at least seven patients had a positive response, the null hypothesis would be rejected, and the intervention would be considered effective.Values to evaluate the response according to final pathologyCategorical variables were reported as number of cases and percentages. Continuous variables were reported as median and interquartile range. Chi-square test was used to evaluate differences in the rate of patients with NIR finding of nodal tissue and with NIR finding of nonnodal tissue according to different baseline characteristics. Overall survival (OS), cancer-related survival and recurrence-free survival (RFS) were calculated with the Kaplan–Meier method. Statistical analyses were performed with the IBM SPSS Advanced Statistics 24.0 package.