Proposal for modified inguinofemoral lymphadenectomy derived from investigation of anatomic distribution of sentinel and metastatic nodes in vulvar cancer.

OBJECTIVE We aimed to develop a less invasive inguinofemoral lymphadenectomy (IFL) approach for vulvar cancer based on the investigation of the anatomic distribution of sentinel and metastatic nodes. METHODS Patients with vulvar cancer treated by surgery between 1995 and 2019 were retrospectively reviewed. A seven-field method was adopted to assign the anatomic locations for lymph nodes removed via IFL or sentinel node biopsy. Only patients with nodal metastasis or sentinel nodes were included. RESULTS A total of 102 patients with eligible data were analyzed. Nodal metastasis was confirmed in 118 groins undergoing IFL; sentinel node detection succeeded in 46 groins. The medial-inguinal field had the highest rate of nodal metastasis involvement (59.3%, 70/118) and sentinel nodes present (73.9%, 34/46). The inferior-femoral field was involved only in one groin with quadruple-field metastases. The lateral-inguinal field was not involved in any groin. Neither the lateral-inguinal nor the inferior-femoral field presented sentinel nodes. CONCLUSION The lateral-inguinal and inferior-femoral fields of the groins have a low risk of developing nodal metastasis. Therefore, a modified IFL preserving these fields can be established to reduce surgical morbidity without sacrificing its therapeutic effect.