Methods for sentinel lymph node mapping in oral cancer: a literature review

Oral cancers, excluding non-melanoma skin cancer, are the most common cancers of the head and neck. Of these, 90% are squamous cell carcinomas (SCC). Surgery, which consists of dissection of the primary tumor and lymphadenectomy, is considered a radical method of treatment. There are several ranges of cervical lymphadenectomy: selective neck dissection (SND), modified radical neck dissection (MRND), and radical neck dissection (RND). The extension of surgery depends on the stage of clinical advancement, which can be determined by TNM classification, among other methods. The greatest controversy is related to SND in patients with cN0 (no evidence of regional lymph node metastasis), which is currently standard procedure. This approach is dictated by the possibility of hidden or subclinical metastases. The use of the sentinel lymph node (SLN) concept in patients with early stage of oral cancer and appropriate methods of its mapping may lead to a reduction in the extent of the lymphadenectomy procedure, thus reducing postoperative mortality and maintaining the patient’s function and quality of life, with correct oncological results. So far, available methods for SLN mapping are based on use of markers: methylene blue dye (MBD), metastable radioactive isotope Technetium (99mTc), or the fluorescent substance indocyanine green (ICG).