The success of sentinel node biopsy, regardless of technique, is markedly dependent on the experience of the surgeon.
The status of the axillary lymph nodes remains one of the most important prognostic factors in women with early stage breast cancer. Histologic examination of excised lymph nodes is the most accurate method for assessing spread of disease to these nodes.
The importance of the sentinel lymph node (SLN) is based upon the observation that tumor cells migrate from a primary tumor metastasize to one or a few lymph nodes (LNs) before involving other LNs. Injection of vital blue dye and/or radiolabeled colloid around the area of the tumor permits identification of a SLN in the majority of patients, and its status accurately predicts the status of the remaining regional LNs.
Radioactive colloid and/or blue dye is injected into the skin of the breast or parenchyma of the breast, usually in the vicinity of the tumor or a subareolar location. These tracers then enter lymphatic channels, and passively flow to LNs. One or a few LNs are labeled, making it possible to identify those first receiving drainage from the tumor.
Common nonradioactive pharmaceuticals used in nuclear medicine are dipyridamole and glucagon. Adverse reactions (usually headache) have been reported to occur in up to 45% of patients. Severe reactions to these occur in about 6 per 100,000 administrations and include prolonged chest pain, syncope (dipyridamole), and anaphylaxis (glucagon). Anaphylactic reactions have also been reported in up to 1% of patients receiving isosulfan blue dye during sentinel lymph node procedures.
Ref: Guiberteau, Mettler and. Essentials of Nuclear Medicine Imaging, 6th Edition. Saunders, 2012. <vbk:9781455701049#outline(22.214.171.124)>.