Sentinel Node Biopsy
What All Breast Cancer and Melanoma Patients Should Know
“Sentinel node biopsy” is the evaluation of the first key node, or group of nodes, draining lymphatic fluid from a tumor basin. It has become the standard of care for many breast cancer and melanoma patients because it provides important prognostic information regarding the status of potential metastasis. In addition, it eliminates the need for the full node dissection in many patients with breast cancer, thus dramatically reducing morbidity since full node dissection which may result in
increased pain, decreased mobility and sensation involving the extremity, as well as the 10% risk of lymphedema (chronic swelling of the extremity due to poor lymphatic fluid outflow).
Lymph nodes are essentially filters of extracellular fluid which can often trap cancer cells that have “escaped” a tumor site and are starting to spread (metastasize). By identifying the sentinel node(s), one can eliminate the need for full node dissection in the patients who do not have evidence of spread. Unlike the full node dissection, this procedure is often performed on an outpatient basis due to the tiny incision required, with minimal risk and morbidity.
The sentinel node is identified by injecting a safe radioactive and a blue dye into the tumor site, then determining the key nodes by subsequent imagining which demonstrates the nodes location. In the operating room, a hand held gamma counter helps to direct the location of the small incision over the node(s) which is (are) removed for pathologic evaluation. The blue dye facilitates visualization of the node and helps to increase the likelihood of its detection to about 99%. Figure 1 demonstrates the sentinel nodes detected in the right axilla in a breast cancer patient. Figure 2 demonstrates the sentinel nodes in the groin on a patient with a left lower extremity melanoma. Fortunately, both of these patients, recently operated on at American Hospital, Dubai proved to have no sign of metastasis, and therefore were not subjected to the full node dissection.
In conclusion, the sentinel node biopsy offers a dramatically improved way to detect evidence of tumor spread, with minimal discomfort and morbidity. Any patient with the diagnosis of breast cancer or melanoma should be aware of this technique, which has been well proven over the past decade to be superior resulting in it becoming the standard of care in all major medical centers around the world. Only by being informed can patients be certain that they are getting the optimal therapy that they deserve.