ABSTRACT
Lymphatic metastasis generally follows an orderly and predictable pattern of progression beginning with the sentinel lymph node. It has been demonstrated that the status of the sentinel node predicts the presence of metastasis in the remainder of the nodal basin. Lymphoscintigraphy is now established as a reliable and minimally invasive technique of identifying the sentinel nodes in solid tumours. Sentinel node biopsy is contraindicated in the following: Advanced stage tumours, clinical or radiological evidence of nodal metastasis and in cases where the neck needs to be exposed for other reasons. Initial attempts at lymph node mapping using the vital dye, isosulphan blue, failed to localize the sentinel nodes in about 20% of cases. Static lymphoscintigraphy involves identifying the nodes with increased radioactivity using a hand-held gamma probe. Sentinel lymph nodes can be identified by three techniques: Isosulphan blue dye, static lymphoscintigraphy and dynamic lymphoscintigraphy.
