Detection of a sentinel lymph node in a patient with lip carcinoma using contrast-enhanced ultrasound – Technology description based on a use case

Introduction

The sentinel lymph node (SLN) is the first lymph node (LN) in the lymphatic drainage area of a tumor and is therefore the first potentially metastatically altered LN. Various methods are currently used to determine the SLN. The standard is usually lymphoscintigraphy, based on the application of technetium-99m-labelled [^99mTc] radiotracers (Mahieu R. et al. Cancers. 2020; 12(10): 3055). CEUS lymphography (CEUS-SLN) offers an innovative approach to sonographically assisted identification of the SLN. This technique is based on the peritumoral application of the ultrasound contrast agent (UCA). The microbubbles are absorbed and transported away by the lymph vessels, whereby UCA shows a rapid entry into the lymphatic vessels. Enhancement of the filled lymphatic vessels can be visualized sonographically using a specialized mode. The lymphatic drainage of the UCA can now be monitored. The first lymph node that absorbs UCA in this way is classified as the SLN. For carcinomas in the head and neck region, there are only 3 proof-of-concept studies concerning the use of CEUS-SLN, each with promising results, but without comparison to an established method of sentinel detection (Gvetadze SR et al. Dentomaxillofacial Radiol. 2017;46(3): 20160345 and Huang J et al. Dentomaxillofacial Radiology. 2022; 51(2): 20210107 and Wakisaka N et al. Acta Otolaryngol. 2019 139(1), 94–99).

The benefit of sentinel node removal compared to neck dissection for carcinomas in the head and neck region is the object of active research. In the last few years, there has been increasing evidence that, for example, there are no differences in survival for T1 and T2 carcinomas of the oral cavity, but that perioperative morbidity is lower in the group with sentinel node removal than for patients undergoing neck dissection (Kang et al. J Laryngol Otol 2023; 137: 599–607). The German S3 guidelines on oral cavity carcinomas describes SLN biopsy as an alternative for early, transorally resectable oral cavity carcinomas (Leitlinienprogramm Onkologie: S3-Leitlinie Diagnostik und Therapie des Mundhöhlenkarzinoms, AWMF Registernummer: 007/100OL https://www.leitlinienprogramm-onkologie.de/leitlinien/mundhoehlenkarzinom/ [accessed on: 01/11/2024]). The establishment of techniques for reliable and simple identification of the SLN is therefore highly relevant. The aim of this paper is to demonstrate the CEUS-SLN technique based on a patient with lip carcinoma.

Publikationsverlauf

Eingereicht: 07. März 2024

Angenommen nach Revision: 25. Februar 2025

Artikel online veröffentlicht:
31. März 2025