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The following is a summary of “Assessing the Comparative Efficacy of Sentinel Lymph Node Detection Techniques in Vulvar Cancer: a Systematic Review and Meta-Analysis,” published in the April 2025 issue of American Journal of Obstetrics & Gynecology by Vida et al. 

Researchers conducted a retrospective study to compare the detection rates (DR) of sentinel lymph node (SLN) methods, including technetium-99m (Tc99m), blue dye (BD), indocyanine green (ICG), and superparamagnetic iron oxide (SPIO), in individuals with vulvar cancer (VC).   

They searched systematically on PubMed, Scopus, Embase, MEDLINE, and Web of Science through August 2024 and included randomized controlled trials (RCTs) and observational studies estimating SLN detection in VC.  The population–intervention–control–outcome (PICO) framework was applied: P — female patients diagnosed with vulvar cancer undergoing SLN biopsy as part of their diagnostic or therapeutic management. I — Tc99m, ICG, SPIO, BD, Tc99m + BD, Tc99m + ICG; C — Tc99m, ICG, SPIO, BD, Tc99m + BD, Tc99m + ICG. O — Primary outcome: DR. The frequentist random-effects model was employed with 95% CI to address heterogeneity. A 3-level multivariate model accounted for within-study correlations when multiple detection methods were analyzed. A classical 2-level meta-analysis was executed to assess publication bias using funnel plots and Peters’ test and evaluated study-level bias with ROBINS-I and RoB 2 tools. Certainty of evidence was assessed using the GRADE Pro tool.  

The results showed that 88 studies, including 4,637 individuals, were analyzed. Per-patient SLN DRs were 78% for BD (95% CI: 69%–85%), 88% for ICG (95% CI: 76%–95%), 95% for SPIO (95% CI: 81%–99%), and 92% for Tc99m (95% CI: 87%–95%). The combined DRs were 94% for Tc99m + BD (95% CI: 91%–96%) and 96% for Tc99m + ICG (95% CI: 90%–99%). Per-groin DRs followed similar patterns, with ICG and Tc99m reaching 87% and 93% when used together. The Tc99m + BD achieved a per-groin DR of 87% (95% CI: 83%–91%), and SPIO demonstrated the second highest per-patient DR but lacked adequate per-groin data for analysis.  

Investigators concluded that ICG provided comparable DRs to Tc99m combined with BD or ICG with fewer logistical issues, suggesting it could replace them in SLN mapping for VC, while SPIO showed great potential but needed more validation. 

Source: ajog.org/article/S0002-9378(25)00274-1/fulltext