Patient Education and Consent
A thorough discussion regarding the indications and potential complications of sentinel lymph node biopsy (SLNB) should be undertaken with each patient. The patient should be educated regarding the predicted probability of node positivity, based on tumor features and other factors. Patients should also agree to postbiopsy recommendations based on SLNB results, which may include further imaging, increased surveillance, completion lymphadenectomy, systemic treatment, and potential for clinical trial enrollment.
Patient Preparation
Currently, the identification rate of sentinel lymph nodes (SLNs) is up to 98%. [32] Initially, Morton and colleagues in the early 1990s used only blue dye and were able to identify SLNs in 194 (82%) of the 237 basins they examined. [14] The identification rates were improved by the use of radiolabeled isotopes. Gershenwald et al increased their identification rates of all sites from 87% to 99% when using 99mTc-labeled sulfur colloid. [33]
The identification rates for SLNs in the head and neck region are somewhat lower than those for other sites. Rates of successful SLN identification range from 90-96%, [34] as compared with higher rates in other body regions. This is largely because of the complex lymphatic pathways of the head and neck anatomy. In addition, the high-density lymphatic basins may cause significant background noise and interfere with use of the gamma probe.
The use of blue dye in combination with lymphoscintigraphy presents challenges specific to the face. Blue dye may persist for several weeks, which can be problematic for this highly visible and cosmetic region. Thus, careful consideration must be given to the use of blue dye, for example limiting its use to the area of resection and reducing the volume if the resection area is small. While blue dye can aid in identification of SLNs, it is generally not necessary for surgeons with substantial experience at head and neck SLN biopsy (SLNB).
Monitoring & Follow-up
For patients with a positive sentinel lymph node biopsy (SLNB), risk stratification is imperative. For low-risk patients, clinicopathologic factors are considered and completion lymph node dissection (CLND) or observation with close follow up and nodal basin monitoring can be offered.
The stage of disease dictates follow-up, as outlined by the National Comprehensive Cancer Network (NCCN) Guidelines (version 2.2021). All patients with melanoma should have a skin examination at least annually for life and should perform regular self-skin and lymph node examinations.
Patients with stage I-IIA disease should undergo physical examinations with attention to skin and nodes every 6-12 months for 5 years and then annually as clinically indicated. Routine laboratory and radiologic testing for surveillance is not recommended.
Patients with stage IIB-IIC disease should undergo physical examinations with attention to skin and nodes every 3-6 months for 2 years, and then every 3-12 months for 3 years. Imaging every 3-12 months for 2 years and then every 6-12 months for an additional 1-3 years should be considered.
Patients with stage IIB-IV should undergo examinations every 3-6 months for 2 years, then every 3-12 months for 3 years, then annually. Imaging every 3-12 months to screen for recurrence or metastasis (not recommended after 3-5 years) should be considered.
Patients with stage III disease and a positive sentinel node should be considered for ultrasound surveillance.
The use of screening chest radiography, CT, positron-emission tomography, and/or MRI in asymptomatic patients is left to the discretion of the treating physician. Previously, providers were not aggressive in obtaining imaging because treatment did not provide meaningful impact for these patients. However, with improving therapeutic options, early detection of recurrence may prove more meaningful, and, thus, routine screening imaging may have increasing value in high-risk patients.
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Lateral cervical lymph nodes I-VI. Level VII nodes are not shown.
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Drainage patterns of the scalp.
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Lymphoscintigraphy of a forehead melanoma with uptake in the parotid and submandibular nodes.
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Survival rates of negative sentinel lymph node versus detection by polymerase chain reaction (PCR) and detection by PCR and H&E.
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Intraoperative left axillary sentinel lymph node seen after uptake with blue dye.
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Confirmation of the sentinel node based on a high radioactive count.
Tables
T |
Thickness, mm |
Ulceration Status/Mitosis |
Tis |
n/a |
n/a |
T1 |
< 0.8 0.8-1 |
a: Without ulceration b: < 0.8 with ulceration or 0.8-1 with or without ulceration |
T2 |
>1-2 |
a: Without ulceration b: With ulceration |
T3 |
>2-4 |
a: Without ulceration b: With ulceration |
T4 |
>4 |
a: Without ulceration b: With ulceration |
N |
No. of Metastatic Nodes or Microsatellite, Satellite, or In-transit Metastasis (MSI) |
Nodal Metastatic Burden |
NX N0 |
Regional lymph nodes not assessed 0 |
No lymph node spread |
N1 |
1 |
a: 1 clinically occult, no MSI b: 1 clinically detected, no MSI c: No regional lymph node disease, but MSI present |
N2 |
2-3 |
a: 2-3 clinically occult, no MSI b: 2-3 with at least 1 clinically detected c: 1 clinically occult or clinically detected and MSI present |
N3 |
≥4 |
a: ≥4 clinically occult, no MSI b: ≥4 at least 1 clinically detected or any number of nodes stuck together, no MSI c: ≥2 clinically occult or clinically detected and MSI present |
M |
Site |
Lactate Dehydrogenase Level |
M0 |
No distant metastases |
n/a |
M1a |
Distant skin, soft tissue, and/or nonregional lymph node |
M1a(0) Not elevated M1a(1) Elevated |
M1b |
Lung metastasis with or without M1a sites of disease |
M1b(0) Not elevated M1b(1) Elevated |
M1c |
Non-CNS visceral metastases with or without M1a or M1b sites of disease |
M1c(0) Not elevated M1c(1) Elevated |
M1d |
Distant to CNS with or without M1a, M1b, or M1c sites of disease |
M1d(0) Not elevated M1d(1) Elevated |
