Sentinel lymph node mapping and selective lymphadenectomy: The standard of care for melanoma

Abstract

Selective sentinel lymphadenectomy (SSL) should be considered a standard of care approach for staging patients with primary invasive melanoma 1 mm or greater. It is essential that multidisciplinary teams should master the techniques of preoperative lymphoscintigraphy, intraoperative lymphatic mapping, and pathologic evaluation of the sentinel lymph nodes (SLNs). An SLN may be blue, hot, or any lymph node (LN) greater than 10% of the in-vivo count of the hottest LN. An enlarged or indurated LN should be removed because it may contain metastatic cancer cells that block blue dye or radiotracer entry. Frozen sections are not recommended. Surgeons who use isosulfan blue dye should be cognizant of treatment for a potentially fatal reaction. Prophylactic LN dissection should not be performed if a SSL can be performed as a staging procedure. A complete LN dissection is performed if the SLN is positive. It is important to follow the clinical outcome of patients undergoing SSL, thus its role can be further defined.

The Biology and Clinical Relevance of Sentinel Lymph Nodes in Melanoma

“…The technique of SLN biopsy is best named selective sentinel lymph node dissection (SLND) and allows surgeons to determine the spread of melanoma through lymphatic channels from the primary tumor; it has substantially impacted the way cutaneous melanoma is staged and managed. The relatively orderly fashion of melanoma metastasis from the primary site to the SLNs and then to the non-SLNs prior to systemic sites is supportive of the spectrum theory of cancer spread (Hellman, 1994;Leong, 2004) [ Fig. 1].…”

“…Despite better survival results, a negative SLN is not an absolute predictor of survival. Recurrence and death in SLN negative patients may be related to FN SLN results or a pure hematogenous spread (Leong et al, 2004. In particular, head and neck melanomas have a higher FN rate, over 12% in some studies (Klop et al, 2011); this is likely due to a complex lymphatic drainage pattern with multiple basins in the head and neck (Leong, 2011).…”

“…Selective SLND is an ideal procedure because it is minimally invasive, yet powerful enough to select the relevant lymph node of the nodal basin, without a complete node dissection. It is now widely accepted that the SLN status is the most important factor in predicting outcomes and determining further treatment for melanoma and this is the focus of the chapter (Leong, 2004). Fig.…”

Tumor-Specific CD8+ T Cell Reactivity in the Sentinel Lymph Node of GM-CSF–Treated Stage I Melanoma Patients is Associated with High Myeloid Dendritic Cell Content

“…Lymphatic mapping and selective SLN excision in patients with melanoma is a minimally invasive procedure, which allows for the identification of patients at-risk for lymph node metastasis who should undergo a full therapeutic tumordraining lymph node dissection. Recent studies have confirmed the SLN procedure to be safe and offers a possible survival benefit (23,24,43). Routine application of this procedure in patients with early stage melanoma presents a unique translational setting to study adjuvant therapies in vivo aimed at the potentiation of immune reactivity within the SLN.…”

“…Twelve patients with stage I melanoma according to criteria of the American Joint Committee on Cancer, scheduled to undergo a SLN procedure were assigned randomly to preoperative local administration of either recombinant human GM-CSF or NaCl 0.9% (22). All patients qualified for a SLN procedure, with Breslow thickness z1 mm or with Breslow thickness V1 mm, but with Clark level zIV, regression, ulceration, or other high-risk factors (23). Patients who had undergone previous immunotherapy or chemotherapy were excluded, as well as patients using immunosuppressive medication, or suffering from any autoimmune disorder.…”