Analysis of results
Images of each patient were reviewed by the operating
consultant plastic surgeon and a consultant radiologist. A
joint opinion was issued on whether the SPECT/CT images
resulted in the detection of any additional SLNs, whether
they provided additional anatomical information, and
whether the information altered surgical approach. All blue
stained nodes and those nodes with a radioactive count
greater or equal to 10% of the ex-vivo count of the hottest
SLN were considered “true” SLNs. Agreement between
each imaging modality and “the truth” was defined as the
detection of nodes equal to or greater than the truth.
Disagreement occurred when imaging detected less SLNs
than the truth. All results were entered into a spreadsheet
for analysis. Bias between lymphoscintigraphy and SPECT/
CT was evaluated by using the sign test. Exact binomial
confidence intervals indicate the uncertainty of the true
value. By compiling a 2 2 contingency table, McNemar’s
test was used to test for a statistically significant difference
between the two methods (p Z