Detecting Atypical Sentinel Lymph Nodes in Early-Stage Cervical Cancer Using a Standardized Technique with a Hybrid Tracer

Abstract

Background: Since October 2018, lymph node status has become part of the FIGO staging, given that it is one of the most important prognostic factors among women with CC. The aim was to determine the rate of atypical lymphatic drainage in patients with clinical early-stage cervical cancer using a hybrid tracer (ICG-99mTc nanocolloid). Methodology: A prospective, observational, single-centre study conducted at Son Espases University Hospital between January 2019 and October 2023. Patients with clinical early-stage CC who underwent SLN mapping were included. External iliac and obturator nodes were defined as common locations. Para-aortic, common iliac, presacral, internal iliac, and parametrial nodes were defined as atypical locations. Results: Thirty-nine cases of CC were included. The overall SLN detection rate was 97.4%, with 89.5% bilaterally. Positive nodes were found in 21.1% of patients. Atypical lymphatic drainage was present in 8 out of 38 (21.1%) patients. Of all the SLNs biopsied (146), 10.3% corresponded to an atypical zone. SLN in the atypical area had a higher proportion of metastasis than the usual area (37.5% vs. 16.7%; p = 0.327). Conclusions: SLN biopsy can detect unusual drainage in a significant proportion of patients. Atypical lymph nodes have a higher percentage of metastasis, which consequently improves staging and tailoring therapy. SLN mapping performed via a standardized surgical technique using a hybrid tracer (ICG-99mTc) could help in the identification of the “true SLN”.