Preoperative sentinel lymph node localization in vulvar cancer: preliminary experience with inguinal intradermal contrast-enhanced ultrasound

Abstract

Objective: To evaluate the feasibility and diagnostic performance of intradermal contrast-enhanced ultrasound (CEUS) sentinel lymph node (SLN) procedure in vulvar cancer.

Methods: Twelve consecutive patients with vulvar cancer underwent preoperatively inguinal CEUS SLN examination and guide wire marking of the enhanced lymph nodes. Altogether, 20 groins were examined with CEUS contrast agent injections including 8 bilateral groins due to midline tumours. One groin was excluded due to previous inguinal surgery. The results of the CEUS examinations were compared to conventional SLN biopsy using radiocolloid scintigraphy and/or methylene blue dye and final postoperative histopathology.

Results: The inguinal sentinel CEUS procedure had a technical success rate of 94.7% (18/19 injections) for identifying a potential inguinal SLN. Conventional SLN biopsy using lymphoscintigraphy and/or methylene blue dye was successfully performed in 16 groins. Compared to conventional SLN biopsy, the overall sensitivity was 81.2% (13/16 injections). Additionally, CEUS detected enhancing SLNs in two cases when traditional SLN procedure failed to do so. All metastatic SLNs (n = 5) were correctly identified by CEUS procedure.

Conclusions: Intradermal CEUS SLN localization can be applied in the inguinal lymphatic region in patients with vulvar cancer. Further studies are needed to verify the clinical value of this method.

Key points: • CEUS is a feasible method for inguinal SLN detection in vulvar cancer • All metastatic inguinal SLNs were identified by CEUS procedure • Further studies are needed to verify the clinical value of this method.

Keywords: Contrast-enhanced ultrasound; Guide-wire marking; Inguinal lymph node; Sentinel lymph node; Vulvar cancer.