Comparison Study of Laparoscopic Sentinel Lymph Node Mapping in Endometrial Carcinoma Using Carbon Nanoparticles and Lymphatic Pathway Verification

Study ObjectiveTo evaluate the detection rate and accuracy of sentinel lymph node (SLN) mapping using cervical and fundal injections of carbon nanoparticles (CNPs) in laparoscopic surgery of endometrioid endometrial cancer (EC) and to identify uterine lymphatic drainage pathways validated by mapping.DesignA prospective consecutive study (Canadian Task Force classification II-2).SettingAn academic research center.PatientsConsecutive patients with a pathologic diagnosis of early-stage EC scheduled for primary laparoscopic-assisted staging surgery (laparoscopic hysterectomy, bilateral salpingo-oophorectomy, or comprehensive lymphadenectomy).InterventionsEnrolled patients underwent laparoscopic SLN mapping with a 50-mg CNP tracer injection. Fifty patients received fundal subserosal injections at 4 sites (the fundal group), whereas 65 patients received cervical submucosal injections at 2 sites (the cervical group). After SLN mapping, all patients underwent laparoscopic staging surgery.Measurements and Main ResultsNo allergic reactions to CNPs were observed in either group. The overall SLN detection rates were 100% and 92% in the cervical and fundal groups, and the bilateral SLN detection rates were 97% and 68% (p < .001), respectively. A total of 12 metastatic SLNs were accurately detected in 5 patients. The sensitivity of metastatic lymph node detection was 100% in the cervical group, which is higher than that in the fundal group (80%). The false-negative rates were 0% and 20%, respectively, in the cervical and fundal groups. Furthermore, we verified 3 uterine lymphatic pathways using the 2 injection methods. The upper paracervical pathway was the most common drainage pathway in both groups (91.4% in the cervical group vs 80.24% in the fundal group), whereas the infundibulopelvic pathway was observed only in the fundal group (15.11%).ConclusionSLN mapping by CNPs in laparoscopic surgery for EC is a safe and effective alternative, with a higher detection rate and better accuracy with cervical injections than fundal injections. The upper paracervical pathway was the most common lymphatic pathway, whereas the infundibulopelvic pathway was only displayed in fundal injections.