Sentinel Lymph Node Biopsy For Melanoma Research Articles

99mTc-Tilmanocept vs. Sulfur Colloid for Sentinel Node Biopsy for Melanoma in the Head and Neck.

The objective of the study is to compare sentinel lymph node (SLN) identification rates and performance characteristics of lymphoscintigraphy using 99mTc-sulfur colloid (SC) and 99mTc-tilmanocept (TL) for head and neck cutaneous melanoma.This study is a retrospective study, conducted at a single, tertiary care cancer center.Patients underwent sentinel lymph node biopsy (SLNB) for head and neck cutaneous melanoma, using SC or TL, between October 2014 and February 2019. Differences in SLN identification rates and performance characteristics between the groups were examined using the Mann-Whitney, or Fisher's exact test. Sixty patients underwent SLNB, of which 19 employed TL. There were no significant differences between SC vs. TL in operative duration (116 vs. 127min, P = 0.97), radiation dose (530 vs. 547μCi, P = 0.27), median number of SLNs removed (3 vs. 2, P = 0.32), or median follow-up (46.3 vs. 38.4months, P = 0.11). The rates of positive SLNs (17% vs. 37%, P = 0.11), intraoperative non-localization (12% vs. 16%, P = 0.70), and false-negative SLNB (5% each, P = 1.00) were not significantly different between groups. In patients with head and neck melanoma undergoing SLNB, 99mTc-tilmanocept may not differ from 99mTc-sulfur colloid in identifying SLNs or other performance characteristics. The added expense related to 99mTc-tilmanocept and lack of favorable performance data should urge caution in its adoption and promote further examination of its value in similar patient cohorts.

Alternatives and reduced need for sentinel lymph node biopsy (SLNB) staging for melanoma

Sentinel lymph node biopsy (SLNB) has been introduced in the 1990s to identify patients who might benefit from completion lymph node dissection. Neither SLNB nor CLND improved survival, but SLNB staging did provide the best staging, above Breslow thickness and ulceration. The SLN status and SLN tumour burden were used in all trials until date looking at modern adjuvant systemic therapy with immune checkpoint inhibition (ICI) or targeted therapies (TT). Adjuvant ICI and TT are shifting towards stage II melanoma. The question is whether there is still role for SLNB in melanoma, in this day and age, and if so, how does the future look for SLNB staging? The SLN status and SLN tumour burden might be useful for a consultation to discuss the number needed to treat in a risk/benefit discussion. For stage IIB/C patients, it seems likely, however, that patients will forego a nuclear scan followed by the risk of surgical intervention and morbidity associated with SLNB if they opt to receive adjuvant therapy regardless of the SLNB result. For stage I/IIA, it is still required to detect high-risk patients who might benefit from adjuvant therapy. However, biomarkers are emerging, such as gene expression profilers (GEP), immunohistological signatures and liquid biopsies with ctDNA. There still is a role for SLNB staging in melanoma today, but we expect that the availability of therapeutic option independent of SLNB status as well as emergence of validated biomarkers to predict risk will reduce the need for SLNB staging in the upcoming decade to the point it will no longer be used.

Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma.

Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fluorescent properties. The aim of this study was to present, for the first time in a clinical series of patients, the possible usage of MB as a fluorescent dye for sentinel node biopsy during surgery for melanoma. Twenty patients with skin melanoma, who were candidates for sentinel node biopsy were enrolled in our study. All patients underwent simultaneous use of standard nanocolloid and blue dye. Transcutaneous visualization of the sentinel node, visualization of lymphatic channels as well as sentinel node fluorescent visualization were all measured. We also performed calculations of Signal to Background ratios (SBR). In 15% (3/20) of patients, the fluorescent sentinel node was visible through the skin. The median SBR for the sentinel node visualization by fluorescence was 3.15 (range, 2.7-3.5). Lymphatic channels were visible in lymphatic tissue via fluorescence before visualization by the naked eye in 4 patients (20%). The median SBR ratio was 3.69 (range, 2.7-4.2). Sentinel nodes were visible by fluorescence in 13 cases (65%). The median SBR ratio was 2.49 (range, 1.5-5.7). No factors were found to be associated with fluorescent MB visualization of a sentinel node during biopsy. This is the first clinical study presenting the usefulness of fluorescent sentinel node biopsy in melanoma patients using MB as a fluorophore. Further studies are necessary to provide methods for its' clinical implementation.

Melanoma sentinel lymph node biopsy and completion lymph node dissection: A regional hospital experience

Completion lymph node dissection (CLND) following positive sentinel lymph node biopsy (SLNB) for cutaneous melanoma is a topic of controversy. The second Multicenter Selective Lymphadenectomy Trial (MSLT-II) suggested no survival benefit with CLND over observation amongst patients with a positive SLNB. The findings of the MSLT-II may have limited applicability to our high-risk population where nodal ultrasound and non-surgical melanoma treatment is rationed. In this regional, retrospective study, we reviewed primary melanoma, SLNB and CLND histopathological reports in the Bay of Plenty District Health Board (BOPDHB) across a 10-year period. The primary outcomes measured were size of sentinel lymph node metastases and non-sentinel node (NSN) positivity on CLND for patients with a positive SLNB. In the 157 SLNB identified, the mean sentinel lymph node metastatic deposit size was larger in BOPDHB compared with MSLT-II (3.53 vs 1.07/1.11mm). A greater proportion of BOPDHB patients (54.8%) had metastatic deposits larger than 1mm compared with MSLT-II (33.2/34.5%) and the rate of NSN involvement on CLND was also higher (23.8% vs 11.5%). These findings indicate that the BOPDHB is a high-risk population for nodal melanoma metastases. Forgoing CLND in the context of a positive SLNB may place these patients at risk.

Local recurrence in patients undergoing wide excision and sentinel lymph node biopsy for cutaneous malignant melanoma: A single-center, retrospective cohort analysis

To the Editor: Primary excision with sentinel lymph node biopsy (SLNB) of the at-risk nodal basin is standard of care for patients with ≥ T1b clinically localized melanoma. Excision is commonly performed via wide local excision (WLE) with 1- to 2-cm clinical margins and bread-loaf pathologic sectioning.1 Previous studies have reported varying local recurrence (LR) rates following WLE, but these studies used heterogeneous definitions of LR across broad ranges of tumor depths.2 This study sought to evaluate the incidence of, and factors and outcomes associated with, LR among a contemporary cohort of patients requiring surgical excision and SLNB for melanoma.

Sentinel Lymph Node Predictors in Melanoma of Breslow Thickness 0.8-1.0 mm

Introduction: Current melanoma staging guidelines consider all patients staged T1b to have the same metastatic risk and recommends that sentinel lymph node biopsy (SLNB) be considered in this disparate group. The goals of this study were to specifically determine predictors of sentinel lymph node positivity and those predictive for obtaining a SLNB in melanomas of Breslow thickness 0.8 mm to 1.0 mm, which has not been previously studied.Methods: Retrospective review between January 1997 and July 2019 of patients with melanomas between 0.8 mm-1.0 mm in thickness. Patient demographics and primary tumor characteristics were correlated with SLN status.Results: Of the 458 patients found to meet Breslow thickness criteria, 223 (61.8%) underwent SLNB. Multivariate analyses demonstrated that < 60 years of age (OR 2.42), increasing Breslow thickness (OR 1.27), mitotic rate >1 (OR 2.32) and presence of tumor infiltrating lymphocytes (OR 3.33), were associated with performing a SLNB. Positive SLNB was found in 20 (8.1 %). Univariate analyses revealed females (p=0.016) to have an increased risk for positive SLNB.Limitations: Limited number of positive SLN and survival data available.Conclusions: Younger age, Breslow thickness ≥0.9 mm, mitotic rate >1, and presence of tumor infiltrative lymphocytes were found to be factors predictive of performing SLNB. Female gender significantly increased the odds of a positive SLN.

Compounding Benefits of Sentinel Lymph Node Biopsy for Perineal Melanoma: A Population-Based Retrospective Cohort Analysis.

Sentinel lymph node biopsy (SLNB) in the treatment of melanoma is known to provide valuable prognostic information. However, there is no literature describing an overall or disease-specific survival (DDS) benefit of SLNB. In the perineum, melanoma is often more advanced at presentation with current treatment guidelines translated from nonanatomic specific melanoma. As a result, there is little understanding surrounding the role of SLNB in melanoma of the perineum. Our objective is to better understand the therapeutic benefits of SLNB in perineal melanoma. The Surveillance, Epidemiology, and End Results program is a large population-based cancer registry including survival data from millions of patients in the United States. The registry was used to generate patient data for analysis from 2004 to 2016. Inclusion criteria included melanoma of the perineum; Breslow depth of 0.80 mm or greater and less than 0.80 mm with ulceration; SLNB or no intervention; clinically negative nodal disease; and available overall survival data. For 879 patients from 2004 to 2016 with perineal melanoma, significant predictors of reduced survival include older than 75 years, Clark level IV-V, Breslow depth of greater than 4.00 mm, positive ulceration status, regional and distant nodal micrometastases, and clinically positive nodes on presentation. Aggregates for overall survival (OS) and disease-specific survival (DSS) were improved with implementation of SLNB. The 5-year survival rates with SLNB versus no SLNB were 54.0% and 43.0% for OS (P = 0.001) and 57.8% and 53.1% for DSS (P = 0.044). Stratification by Breslow depth yielded significant OS and DSS advantage for greater than 1.00 to 2.00 mm (21.3% benefit, P =0.021, and 16.8% benefit, P = 0.044) and greater than 4.00 mm (30.3% benefit, P = 0.005, and 21.0% benefit, P = 0.007) Breslow depths. Sentinel lymph node biopsy may provide therapeutic benefits in addition to prognostic information for melanoma of the perineum through an increase in 5-year OS.

Abstract 176: ICG-fluorescence Imaging With Lymphoscintigraphy For Sentinel Node Biopsy In Melanoma: Reducing The False Negative Rate

Purpose: In melanoma, sentinel lymph node (SLN) status has shown to be the best predictor of disease-free survival and identifying the correct SLN is of paramount importance to enable appropriate adjuvant work-up and treatment. Despite the advances in cutaneous melanoma management, the false negative rate (FNR) of sentinel lymph node biopsy (SLNB) is still reported to be as high as 29.8%. The majority of studies examining ICG-guided SLNB in melanoma are retrospective studies with inadequate sample size and follow-up time, making calculation of FNR difficult. Amongst studies with large cohorts of patients (>300) and at least two-years mean or median follow-up, the FNR ranges from 13.4-29.8%. Indocyanine green (ICG) fluorescence imaging has improved identification of SLNs in numerous cancers. The goal of this study was to analyze the largest cohort of patients with primary cutaneous melanoma who underwent a SLNB with the combination of lymphoscintography and ICG-based fluorescence to determine the FNR. Methods: Consecutive primary cutaneous melanoma patients who underwent radioisotope lymphocintigraphy and ICG-based fluorescence imaging for SLNB by the senior author from 2012-2018 were prospectively enrolled. All patients were staged according to AJCC version 8. The FNR was calculated based on the formula FN/TP+FN. Results: 594 melanomas were analyzed, of which there were 130 T1a, 114 T1b, 148 T2a, 34 T2b, 46 T3a, 56 T3b, 22 T4a and 43 T4b. At least one SLN was identified in every patient. 1827 nodes were sampled. 1556 (85.2%) were identified by radioactivity/fluorescence, 255 (14%) by radioactivity only and 16 (0.9%) with fluorescence only. There were 163 positive sentinel nodes. 147 (90.2%) were identified by radioactivity/fluorescence, 13 (8%) by radioactivity only and 3 (0.6%) with fluorescence only. Of the 128 true positive patients, 116 (90.6%) had at least one positive node identified by radioactivity/fluorescence, 8 (6.3%) by radioactivity only and 4 (3.4%) with fluorescence only. There were 128 true positive, 454 true negative and 12 false negative patients. The FNR was 8.6%. Mean follow up was 1030.9 days. Conclusion: In our cohort, while the majority of positive nodes were identified by both radioactivity and fluorescence, for 12 patients, their only positive node was identified by only radioactivity or fluorescence. Thus, without dual modality, these nodes may have been missed and patients may not have been accurately staged and allocated adjuvant therapy. The FNR of our study at 8.6% is lower than that of any large cohort study with at least two-year follow-up, including the Sunbelt Melanoma trial, the largest prospective study examining nodal recurrence in melanoma patients, which demonstrated a FNR of 10.8%. In conclusion, in the study of the largest cohort of patient with primary cutaneous melanoma who underwent a SLNB with radioisotope lymphocintigraphy and ICG-based technology, we demonstrate the lowest reported FNR amongst large studies with at least two-year follow-up. This has important implications for melanoma patients as the widespread adoption of this technique with subsequent accurate staging, adjuvant work-up and treatment may improve survival outcomes.

Relationship of patient age to tumor factors and outcomes among patients undergoing sentinel node biopsy for melanoma

IntroductionPatient age has been intermittently associated with demographics and outcomes in cutaneous melanoma. We looked at the association of age and patient demographics, tumor features, and melanoma-related outcomes in patients undergoing sentinel lymph node (SLN) biopsy for melanoma. MethodsWe reviewed demographics (age, gender), tumor features (mean Breslow thickness, ulceration, SLN positivity rates), and outcomes (all-site relapse, progression to stage IV, death from melanoma, complications) from a university-based prospective database of 1633 patients. Patients were grouped by decade of age and the impact of age was examined by univariable and multivariable analyses. ResultsIncreasing age was directly associated with number of patients referred for SLN biopsy, male gender, head and neck (H&N) tumor location, mean Breslow thickness, tumor ulceration, and with all –site relapse, progression to stage IV, death from melanoma and complication rates. Increasing age was indirectly associated with SLN positivity rates. Comparing ages <30 with ages >60, these trends reached statistical significance for male gender, H&N location, SLN positivity, all-site relapse, progression to stage IV (development of metastases) and death from melanoma. ConclusionsReferrals for SLN biopsy increase with increasing patient age, yet increasing age is associated with lower SLN positivity rates. This occurs despite the fact that older patients have thicker, more ulcerated tumors, and higher melanoma-related relapse and death rates.

Sentinel lymph node biopsy for melanoma of the head and neck: a multicentre study to examine safety, efficacy, and prognostic value

Sentinel lymph node biopsy (SLNB) is an accurate staging procedure for malignant melanoma but its use in patients with melanoma of the head and neck has been questioned in the past because of a perceived record of poor safety and accuracy. Technical improvements have sought to redress this. Vital structures and variable lymphatic pathways can make its use in the head and neck challenging. In our study we have examined the data and the experiences of clinicians from University Hospital Southampton and the Royal Surrey County Hospital. We retrospectively analysed the data and case notes of 143 patients who had SLNB to establish its safety, efficacy, and prognostic value. The detection rate of at least one sentinel lymph node was 100%. Nodes positive for metastatic melanoma were found in 20% of patients. Of them, 76% went on to have completion lymphadenectomy. Multivariate Cox regression analysis suggested that positive SLNB was a strong predictor of reduced overall survival for all Breslow-thickness melanomas (HR=3.9, p=0.019) and intermediate melanomas (HR=6.3, p=0.007). It predicted reduced recurrence-free survival for all melanomas (HR=7.4, p<0.001) and was a strong predictor for those of intermediate thickness (HR=8.3, p<0.001). The false negative rate was 9.4% and false omission rate 2.6%. Temporary and permanent morbidity rates were 2.1% and 0%, respectively. SLNB for melanoma in the head and neck is a safe, accurate staging procedure that offers prognostically useful information. The upstaging of disease allows access to trial-based targeted treatments.

Reduction of lymphocele rate in patients undergoing sentinel node biopsy for melanoma by intraoperative placement of plant-based hemostatic powder: Results of a prospective trial

BackgroundLymphocele is a complication of sentinel node biopsy (SNB) for melanoma. Plant-based hemostatic powder (PBHP) may have a lymphostatic benefit. We studied whether PBHP placed intraoperatively could reduce lymphocele rates. MethodsWe performed an open label, prospective, IRB -approved, before- and-after, matched control trial of PBHP placed into the wound in patients undergoing SNB of groin or axillary nodes for melanoma staging. Patient/tumor features and lymphocele rates were compared by standard statistical tests. Results66 control and 66 treatment (49 axillary and 17 groin in each arm) SNBs were performed in 61 and 55 patients, respectively, for a total 132 SNBs in 116 patients. Patient and tumor features were similar between groups. Nineteen lymphoceles occurred (14.4%); lymphocele rates were 22.2% (14/66) in the control group and 7.6% (5/66) in the treatment group (p = 0.026). The reduction in lymphocele rates between arms was greater for axillary than for groin sites (87.5% vs. 33%); the axillary reduction was statistically significant (p = 0.030). ConclusionsIntra-operative placement of PBHP reduced the rate of lymphoceles in patients undergoing SNB for melanoma.

Sentinel lymph node biopsy for in situ melanoma is unlikely in Australia

We commend Badgery-Parker and colleagues for their comprehensive review of ‘low-value’ healthcare provided at public hospitals in New South Wales (NSW), Australia and support their initiative to identify low-value care.1...

Lymphatic Mapping and Sentinel Node Biopsy

With an estimated 232,670 new cases in the United States in 2014, breast cancer is among the most common malignancies treated by US surgeons. Meanwhile, the incidence of melanoma is rising faster than for all other solid malignancies, with an estimated 76,100 new cases of invasive melanoma in the United States in 2014. Over the past 20 years, significant strides have been made in the management of these two diseases from the standpoint of both surgical and adjuvant therapy. For both diseases, the presence or absence of lymph node metastases is highly predictive of patient outcome and is the most important prognostic factor for disease recurrence and cancer-related mortality. This review covers lymphatic mapping and sentinel node biopsy for melanoma, special circumstances associated with sentinel node biopsy in melanoma, lymphatic mapping and sentinel node biopsy in breast cancer, and radiation exposure guidelines and policies. The figures show lymphatic mapping and sentinel lymph node biopsy for melanoma, lymphatic mapping and sentinel node biopsy for breast cancer, and touch-imprint cytology from lymphatic mapping and sentinel node biopsy for breast cancer. This review contains 3 highly rendered figures and 89 references.

Sentinel lymph node biopsy in melanoma: Which hot nodes should be harvested and is blue dye really necessary?

ObjectivesThe ‘10% rule’ has become widely accepted by surgeons performing sentinel lymph node biopsy (SLNB) for melanoma. The purpose of this study was to compare the ‘10% rule’ with alternative node harvesting criteria. In particular, we were interested to see whether the use of blue dye had any impact on the sensitivity of the test and whether it is necessary to remove all hot nodes. MethodsWe reviewed 537 SLNBs performed for primary melanoma from 2009–2015. SLNB was offered to all patients with 1–4 mm Breslow thickness melanoma and sentinel nodes were harvested according to the ‘10% rule’. ResultsOne hundred sixteen patients (22%) had at least one positive sentinel node and there were 45 positive nodal basins from which more than one sentinel node had been harvested. Excluding blue dye and sampling only hot nodes would have enabled a 5% reduction in nodes harvested, without any compromise in the sensitivity of the test. However, applying harvesting criteria whereby not all hot nodes are taken was associated with a loss of sensitivity, with positive sentinel nodes being missed and patients understaged. ConclusionsOur data do not support the continued use of blue dye in SLNB for melanoma, as it does not improve the sensitivity of the test. This series adds to growing evidence, suggesting that the ‘10% rule’ with the inclusion of blue nodes should be reconsidered and that radiocolloid tracer alone is sufficient for sentinel node localisation.

Completion lymphadenectomy for sentinel node positive cutaneous head & neck melanoma.

The application and utility of melanoma sentinel lymph node biopsy (SLNB) has evolved significantly since its inception over two decades ago. The current focus has shifted from a staging modality to potentially a therapeutic intervention. Recent research to include large multi‐institutional randomized trials have attempted to answer the question: is a completion lymph node dissection (CLND) required following a positive SLNB? This review provides an evidence‐based, contemporary review of the utility of CLND for SLNB positive head and neck cutaneous melanoma patients.Level of EvidenceNA

Lymphatic Mapping and Sentinel Node Biopsy

With an estimated 232,670 new cases in the United States in 2014, breast cancer is among the most common malignancies treated by US surgeons. Meanwhile, the incidence of melanoma is rising faster than for all other solid malignancies, with an estimated 76,100 new cases of invasive melanoma in the United States in 2014. Over the past 20 years, significant strides have been made in the management of these two diseases from the standpoint of both surgical and adjuvant therapy. For both diseases, the presence or absence of lymph node metastases is highly predictive of patient outcome and is the most important prognostic factor for disease recurrence and cancer-related mortality. This review covers lymphatic mapping and sentinel node biopsy for melanoma, special circumstances associated with sentinel node biopsy in melanoma, lymphatic mapping and sentinel node biopsy in breast cancer, and radiation exposure guidelines and policies. The figures show lymphatic mapping and sentinel lymph node biopsy for melanoma, lymphatic mapping and sentinel node biopsy for breast cancer, and touch-imprint cytology from lymphatic mapping and sentinel node biopsy for breast cancer. This review contains 3 highly rendered figures and 89 references.

Localization of the Sentinel Lymph Node in Melanoma Without Blue Dye.

The purpose of this study was to assess regional recurrence rates of patients who underwent sentinel lymph node biopsy (SLNB) using radiocolloid guidance alone. Isosulfan blue dye is commonly used along with Tc99-labeled radiocolloid localization in SLNB for melanoma. Blue dye has, however, been associated with allergic reactions, long-term staining of skin, and increased cost. We hypothesized that the rate of regional recurrence when SLNB is performed with radiocolloid alone would be comparable to established reports using both radiocolloid and blue dye. A prospectively collected database was retrospectively queried for patients who underwent SLNB for melanoma during the years 2005 through 2008. Data collected included patient demographics, primary lesion characteristics, operative details, and recurrence. The primary outcome was the rate of recurrence within the biopsied basin after negative SLNB's performed without isosulfan blue dye. In 215 patients, 279 nodal basins were identified. All patients underwent successful radiocolloid localization, and positive sentinel nodes were found in 40 patients (18.6%). Six of 175 patients with a negative SLNB developed a regional node recurrence as the first site of metastasis (3.4%). Among all 215 patients, 44 experienced recurrence of any kind (20.5%). Higher mitotic rate and Breslow depth were significantly associated with likelihood of recurrence. Success rates, node positivity rates, and rates of regional recurrence after SLNB for melanoma using radiocolloid alone are acceptable and similar to those of prior reports using blue dye plus radiocolloid.

Axillary web syndrome: an underappreciated complication of sentinel node biopsy in melanoma

ObjectiveAxillary web syndrome (AWS) is known to occur after axillary dissection and has been reported after axillary sentinel lymph node biopsy (ASLNB) for breast cancer. However, the incidence and outcomes of AWS after ASLNB for melanoma are unknown. MethodsA retrospective review of prospectively collected, clinically node-negative patients undergoing ASLNB for melanoma at a single institution during a 14-year period was conducted to determine the incidence of AWS. Features pertaining to patients (age and gender), primary tumor (location, Breslow's depth), and nodes (number removed, positive node rate) were correlated with the occurrence of AWS. ResultsOf the 465 patients undergoing ASLNB, 21 (4.5%) developed AWS postoperatively. In comparison, the incidence of other complications in this population were infection 3%, bleeding 1.5%, wound dehiscence .8%, lymphocele 5%, and lymphedema .4%. There was no statistical difference between patients with or without AWS in terms of tumor thickness, location of primary (upper extremity vs trunk), average number of sentinel nodes removed, positive SLNB rates (10% vs 12%), patient age, or gender. All cases of AWS resolved with expectant management; none required surgical intervention. ConclusionsAWS is a notable complication of ASLNB for melanoma, with an incidence as high or higher than “standard” complications. AWS should, therefore, be included in the preoperative discussion of possible complications of ASLNB. Traditional patient, tumor, and nodal factors are not predictive of AWS. Patients should be counseled that AWS usually responds to symptomatic treatment and resolves with time.

Lymphatic Mapping and Sentinel Node Biopsy in Melanoma.

Lymphatic Mapping and Sentinel Node Biopsy in Melanoma.

Lymphoscintigraphy and sentinel nodes.

It has been validated that sentinel lymph node biopsy (SLNB) shows whether a patient's breast cancer or melanoma has spread to regional lymph nodes. As a result, management of patients with these cancers has been revolutionized. SLNB has replaced axillary lymph node dissection (ALND) as the staging modality of choice for early breast cancer and has replaced complete lymph node dissection as the staging modality of choice for melanoma in patients whose SLNBs indicate no metastases. Recently concluded multicenter, randomized trials for breast cancer with 5- to 10-y outcome data have shown no significant differences in disease-free survival rates or overall survival rates between SLNB and ALND groups but have shown significantly lower morbidity with SLNB than with ALND. The lowest false-negative rates (5.5%-6.7%) were seen in studies that used preoperative lymphoscintigraphy and dual mapping during surgery. To assess the survival impact of SLNB in melanoma, the Multicenter Selective Lymphadenectomy Trial I was performed. Melanoma-specific survival rates were not different between subjects randomized to SLNB with lymphadenectomy for nodal metastasis on biopsy and subjects randomized to observation with lymphadenectomy for nodal relapse. However, the 10-y disease-free survival rates were better for the SLNB group than for the observation group, specifically among patients with intermediate-thickness melanomas or thick melanomas.