Main Results
The pooled sensitivity of FSE among 31 eligible studies (1887 patients) was 0.77 (95% CI 0.66–0.85) with high heterogeneity (I 2=69.73%). Two representative FSE protocols were identified from 26 studies, described as equatorial (E-protocol, SLN was bisected) and latitudinal (L-protocol, SLN was cut at intervals). Meta-regression showed that FSE protocol was the only source of heterogeneity (p<0.001). The pooled sensitivity was 0.86 (95% CI 0.79–0.91,I 2=0%) and 0.59 (0.46–0.72,I 2=58.47%) for FSE using L- and E- protocol, respectively. The pooled sensitivity of FSE using L-protocol would reach 0.97 (0.89–0.99) if only marcometastases were considered. These findings were robust to sensitivity analyses.