Sentinel node mapping in cervical and endometrial cancer: indocyanine green versus other conventional dyes. A meta-analysis

BACKGROUND: Historically, blue dyes, 99Tc or a combination of the two tracers have been used for sentinel lymph node (SLN) mapping in cervical and endometrial cancer patients. Indocyanine green (ICG), as a tracer, has been recently introduced in this setting. Our goal was to assess the differences in overall and bilateral detection rates as well as in false-negative rates among the different tracers. METHODS: The electronic databases PubMed, MEDLINE, and Scopus were searched in January 2016 by searching the terms "sentinel lymph node" and "dye" and "indocyanine green," and "cervical cancer" or "endometrial cancer." Series comparing different tracers injected intracervically and reporting the detection rate and/or SLN false-negative rate were selected. RESULTS: Forty-five studies were retrieved. Six studies including 538 patients met selection criteria. Compared with blue dyes, ICG SLN mapping had higher overall (odds ratio [OR] 0.27; 95 % confidence interval [CI] 0.15-0.50; p < 0.0001) and bilateral detection rates (OR 0.27; 95 % CI 0.19-0.40; p < 0.00001). No differences were found between ICG and 99TC, although these results are based on data of a single series. No differences in overall and bilateral detection rates were found between ICG and the combination of blue dyes and 99TC. The pooled analysis of false-negative rates data showed no difference in false-negative rates between tracers. CONCLUSIONS: In cervical and endometrial cancer, ICG SLN mapping seems to be equivalent to the combination of blue dyes and 99TC in terms of overall and bilateral detection rates. Its safety profile and ease of use may favor its employment respect to conventional tracers.