Sentinel lymph node biopsy in oral cavity cancer

Abstract

This thesis addresses a major challenge in head and neck surgical oncology; detection of lymphatic metastasis in patients with early stage oral cancer. The sentinel lymph node biopsy (SLNB) procedure has been introduced as a diagnostic staging procedure to identify those lymphatic metastases, which are an important prognostic factor. This thesis concluded that SLNB alone is a safe and reliable staging procedure, preventing an (unnecessary) neck dissection with associated morbidity in 70% of the patients. However, this high accuracy was not achieved in patients with floor of mouth tumours. Improved imaging by means of SPECT-CT showed more often a sentinel lymph node, but was not sufficient to solve the problem of “shine-through” phenomenon from the injection site in this type of tumours. We investigated a new radioactive tracer (with specific characteristics for the detection of sentinel lymph nodes) and compared this tracer per patient with the currently used detection method. Although the sentinel lymph node could sometimes be more clearly visualized, the new tracer was not found to be superior to the routine tracer. The SLNB procedure could also be used reliably in patients who have been treated previously in the neck and should also be used for superficial tumours. Although we often found only isolated tumour cells or micrometastases in the sentinel lymph nodes, an additional neck dissection can not be safely omitted. The SLNB procedure in oral cancer is receiving generally more attention worldwide and is being used increasingly as diagnostic method. This thesis provides evidence for its applicability and suitability. Furthermore, this thesis addresses important unmet needs that should be further explored in the near future.