Differences in sentinel lymph node biopsy utilization in eligible melanoma patients treated with Mohs micrographic surgery or wide local excision: A population-based logistic regression model and survival analysis

BACKGROUND

Primary melanoma management relies on tumor extirpation and staging sentinel lymph node biopsy (SLNB) in eligible patients. This study compares SLNB utilization in patients undergoing wide local excision (WLE) or Mohs micrographic surgery (MMS).

METHODS

American Joint Committee on Cancer seventh edition ≥ patients with T1b melanoma undergoing WLE or MMS in the Surveillance, Epidemiology, and End Results program were included. Propensity score matching was performed to compare patients who underwent MMS or WLE. Kaplan-Meier analysis and Fine-Gray cumulative incidence functions were used for overall and melanoma-specific survival.

RESULTS

Eight hundred twenty-five MMS cases and 38,760 WLE cases were identified. SLNB was performed in 32.61% of MMS patients and 61.77% of WLE patients with positive rates of 12.5% and 14.82%, respectively. Multiple logistic regression of factors associated with SLNB utilization revealed that WLE, male gender, younger age, extremity location, and nodular and rare melanoma subtypes were significantly associated with increased odds of receiving SLNB whereas head and neck location and lentigo maligna melanoma subtype were significantly less likely to receive SLNB.

LIMITATIONS

Potential selection bias from a retrospective data set.

CONCLUSION

Patients receiving WLE for ≥ T1b melanoma are more likely to receive a SLNB than patients undergoing MMS.

Classification of Metastatic Lymph Nodes In Vivo Using Quantitative Ultrasound at Clinical Frequencies

Quantitative ultrasound (QUS) methods characterizing the backscattered echo signal have been of use in assessing tissue microstructure. High-frequency (30 MHz) QUS methods have been successful in detecting metastases in surgically excised lymph nodes (LNs), but limited evidence exists regarding the efficacy of QUS for evaluating LNs in vivo at clinical frequencies (2-10 MHz). In this study, a clinical scanner and 10-MHz linear probe were used to collect radiofrequency (RF) echo data of LNs in vivo from 19 cancer patients. QUS methods were applied to estimate parameters derived from the backscatter coefficient (BSC) and statistics of the envelope-detected RF signal. QUS parameters were used to train classifiers based on linear discriminant analysis (LDA) and support vector machines (SVMs). Two BSC-based parameters, scatterer diameter and acoustic concentration, were the most effective for accurately detecting metastatic LNs, with both LDA and SVMs achieving areas under the receiver operating characteristic (AUROC) curve ≥0.94. A strategy of classifying LNs based on the echo frame with the highest cancer probability improved performance to 88% specificity at 100% sensitivity (AUROC = 0.99). These results provide encouraging evidence that QUS applied at clinical frequencies may be effective at accurately identifying metastatic LNs in vivo, helping in diagnosis while reducing unnecessary biopsies and surgical treatments.

The Evolution of the Sentinel Node Biopsy in Melanoma

The growing repertoire of approved immune-checkpoint inhibitors and targeted therapy has revolutionized the adjuvant treatment of melanoma. While the treatment of primary cutaneous melanoma remains wide local excision (WLE), the management of regional lymph nodes continues to evolve in light of practice-changing clinical trials and dramatically improved adjuvant therapy. With large multicenter studies reporting no benefit in overall survival for completion lymph node dissection (CLND) after a positive sentinel node biopsy (SLNB), controversy remains regarding patient selection and clinical decision-making. This review explores the evolution of the SLNB in cutaneous melanoma in the context of a rapidly changing adjuvant treatment landscape, summarizing the key clinical trials which shaped current practice guidelines.

The Utility of Indocyanine Green Dye Fluorescence Lymphography and Angiography During Wide Excision of Cutaneous Melanoma

Background and Objectives. Lymph node status is the most important prognostic factor in cutaneous melanoma patients. Recent studies showed that indocyanine green (ICG) fluorescence lymphography helps locating sentinel nodes better. Sometimes, flap reconstruction is needed after wide excision of tumor. Indocyanine green fluorescence also simplifies the intraoperative design of flaps. This study investigates the use of ICG fluorescence in patients with cutaneous melanoma during operation. Methods. We performed a single-center, retrospective study of subjects with cutaneous melanoma using ICG lymphograhy and/or angiography during wide excision of tumor between 2015 and 2019. Patients received a dermal injection of ICG and patent blue (PB) dye. The positive node was excised. Indocyanine green angiography was utilized to visualize better skin paddle during flap reconstruction if needed. Results. A total of 37 sentinel lymph nodes (SLNs) were removed in 12 patients. Indocyanine green successful localization was found in 10 of the 12 patients (83%). Three patients were found with 6 metastatic nodes on final pathology. 100% of these 6 nodes were identified by ICG, while 83% (5/6) were positive PB. Three of the 12 patients received flap reconstruction after operation, and no major complications occurred. Conclusions. ICG dye lymphangiography is a good alternative for locating SLNs in patients with melanoma. It could also visualize well perfusion skin paddle during reconstruction. We reported a reproducible and simple method to utilize ICG fluorescence in cutaneous melanoma patients.

Predictive factors for false negatives following sentinel lymph node biopsy in early oral cavity cancer

Prophylactic elective neck dissection (ND) with navigation surgery using radioisotope-based sentinel lymph node biopsy (SLNB) is non-inferior to elective ND in terms of survival but has an advantage in postoperative functional disability. We conducted a subgroup analysis to identify predictive factors for false-negative (FN)-SLNB in patients with early oral cavity cancer. This study is a supplementary analysis using the dataset of a previously reported randomized clinical trial on SLN navigation surgery for oral cancers. This study investigated the association of clinical and SLN-related factors with false-negative cases in the SLNB group. From 2011 to 2016, 275 patients were enrolled and randomly assigned to the ND and SLNB study groups, with 134 patients assigned to the SLNB group. In the SLNB group, seven cases with negative SLNs and neck recurrences were judged as FN-SLNBs according to the general definition. The number of detected SLNs with and without adjusting for the propensity score was significantly associated with FNs in the logistic analysis. FN-SLNB was associated with the number of identified SLNs, suggesting the need for careful postoperative monitoring for neck recurrence in patients with one or two identified SLNs after acquiring sufficient experience in the identification technique.

Does the pattern of lymphatic drainage influence the risk of nodal recurrence in trunk melanoma patients with negative sentinel lymph node biopsy?

Background

There are conflicting data regarding the prognostic value of the lymphatic basin drainage pattern in melanoma patients and the evidence is scant in the setting of negative sentinel lymph node biopsy.

Objective

To investigate whether the pattern of lymphatic basin drainage influences the risk of nodal disease in patients with melanoma of the trunk and negative sentinel lymph node biopsy.

Methods

A case series of patients with trunk melanoma and negative sentinel lymph node biopsy was retrospectively evaluated. Clinicopathological features, the pattern of lymphatic drainage and nodal, metastatic, and overall recurrence-free survival were reviewed.

Results

Of the 135 patients included, multiple lymphatic basin drainage was identified in 61 (45.2%). Ten of the 74 (13.5%) patients with single drainage developed nodal recurrence, compared with 2 of the 61 (3.6%) patients with multiple drainages (p = 0.04). Nodal recurrence-free survival was significantly longer in the group with multiple drainages than in the group with single drainage (175.6 vs. 138.7 months; p = 0.04). In multivariate analysis, single drainage was associated with a higher risk of nodal recurrence (HR = 4.54; p = 0.05). No significant differences in metastatic and overall recurrence-free survival were found between groups.

Study limitations

Retrospective analysis, single-center study, small sample, detailed histopathologic information not always present.

Conclusions

In patients with trunk melanoma and negative sentinel lymph node biopsy, multiple lymphatic basin drainage may be an independent risk factor for nodal disease recurrence. This factor may help to identify patients with negative sentinel lymph node biopsy with a higher risk of nodal recurrence.

Indocyanine Green Fluorescence Imaging with Lymphoscintigraphy Improves the Accuracy of Sentinel Lymph Node Biopsy in Melanoma

BACKGROUND

Despite advances in melanoma management, there remains room for improvement in the accuracy of sentinel lymph node biopsy. The authors analyzed a prospective cohort of patients with primary cutaneous melanoma who underwent sentinel lymph node biopsy with lymphoscintigraphy and indocyanine green fluorescence to evaluate the quality and accuracy of this technique.

METHODS

Consecutive primary cutaneous melanoma patients who underwent sentinel lymph node biopsy with radioisotope lymphoscintigraphy and indocyanine green fluorescence from 2012 to 2018 were prospectively enrolled. Analysis was performed of melanoma characteristics, means of identifying sentinel lymph nodes, sentinel lymph node status, and recurrence.

RESULTS

Five hundred ninety-four melanomas and 1827 nodes were analyzed; 1556 nodes (85.2 percent) were identified by radioactivity/fluorescence, 255 (14 percent) by radioactivity only, and 16 (0.9 percent) with indocyanine green only. There were 163 positive sentinel nodes. One hundred forty-seven (90.2 percent) were identified by radioactivity/fluorescence, 13 (8 percent) by radioactivity only, and three (0.6 percent) with fluorescence only. Of the 128 patients with a positive biopsy, eight patients' (6.3 percent) nodes were identified by radioactivity only and four (3.4 percent) with fluorescence only. There were 128 patients with a positive biopsy, 454 with a negative biopsy, and 12 patients who had a negative biopsy with subsequent nodal recurrence. Mean follow-up was 2.8 years.

CONCLUSIONS

In the study of the largest cohort of patients with primary cutaneous melanoma who underwent a sentinel lymph node biopsy with radioisotope lymphoscintigraphy and indocyanine green-based technology, the quality and accuracy of this technique are demonstrated. This has important implications for melanoma patients, as the adoption of this approach with subsequent accurate staging, adjuvant workup, and treatment may improve survival outcomes. .

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

Predictors of False Negative Sentinel Lymph Node Biopsy in Clinically Localized Merkel Cell Carcinoma

BACKGROUND

Sentinel lymph node biopsy (SLNB) is routinely recommended for clinically localized Merkel cell carcinoma (MCC); however, predictors of false negative (FN) SLNB are undefined.

METHODS

Patients from six centers undergoing wide excision and SLNB for stage I/II MCC (2005-2020) were identified and were classified as having either a true positive (TP), true negative (TN) or FN SLNB. Predictors of FN SLNB were identified and survival outcomes were estimated.

RESULTS

Of 525 patients, 28 (5.4%), 329 (62.7%), and 168 (32%) were classified as FN, TN, and TP, respectively, giving an FN rate of 14.3% and negative predictive value of 92.2% for SLNB. Median follow-up for SLNB-negative patients was 27 months, and median time to nodal recurrence for FN patients was 7 months. Male sex (hazard ratio [HR] 3.15, p = 0.034) and lymphovascular invasion (LVI) (HR 2.22, p = 0.048) significantly correlated with FN, and increasing age trended toward significance (HR 1.04, p = 0.067). The 3-year regional nodal recurrence-free survival for males >75 years with LVI was 78.5% versus 97.4% for females ≤75 years without LVI (p = 0.009). Five-year disease-specific survival (90.9% TN vs. 51.3% FN, p < 0.001) and overall survival (69.9% TN vs. 48.1% FN, p = 0.035) were significantly worse for FN patients.

CONCLUSION

Failure to detect regional nodal microscopic disease by SLNB is associated with worse survival in clinically localized MCC. Males, patients >75 years, and those with LVI may be at increased risk for FN SLNB. Consideration of increased nodal surveillance following negative SLNB in these high-risk patients may aid in early identification of regional nodal recurrences.

Cranial nerve outcomes in regionally recurrent head & neck melanoma after sentinel lymph node biopsy

OBJECTIVE

Characterize long-term cranial nerve (CN) outcomes following sentinel lymph node biopsy (SLNB) based management for head and neck cutaneous melanoma (HNCM).

METHODS

Longitudinal review of HNCM patients undergoing SLNB from 1997-2007.

RESULTS

Three hundred fifty-six patients were identified, with mean age 53.5 ± 19.0 years, mean Breslow depth 2.52 ± 1.87 mm, and 4.9 years median follow-up. One hundred five (29.4%) patients had SLNB mapping to the parotid basin. Eighteen patients had positive parotid SLNs and underwent immediate parotidectomy / immediate completion lymph node dissection (iCLND), with six possessing positive parotid non-sentinel lymph nodes (NSLNs). Fifty-two of 356 (14.6%) patients developed delayed regional recurrences, including 20 total intraparotid recurrences: five following false negative (FN) parotid SLNB, three following prior immediate superficial parotidectomy, two following iCLND without parotidectomy, and the remaining 12 parotid recurrences had negative extraparotid SLNBs. Parotid recurrences were multiple (4.9 mean recurrent nodes) and advanced (n = 4 extracapsular extension), and all required salvage dissection including parotidectomy. Immediate parotidectomy/iCLND led to no permanent CN injuries. Delayed regional HNCM macrometastasis precipitated 16 total permanent CN injuries in 13 patients: 10 CN VII, five CN XI, and one CN XII deficits. Fifty percent (n = 10) of parotid recurrences caused ≥1 permanent CN deficits.

CONCLUSIONS

Regional HNCM macrometastases and salvage dissection confer marked CN injury risk, whereas early surgical intervention via SLNB ± iCLND ± immediate parotidectomy yielded no CN injuries. Further, superficial parotidectomy performed in parotid-mapping HNCM does not obviate delayed intraparotid recurrences, which increase risk of CN VII injury. Despite lack of a published disease-specific survival advantage in melanoma, early disease control in cervical and parotid basins is paramount to minimize CN complications.

LEVEL OF EVIDENCE

4 (retrospective case series) Laryngoscope, 130:1707-1714, 2020.

Sentinel Lymph Node Biopsy in Head and Neck Melanoma: Long-term Outcomes, Prognostic Value, Accuracy, and Safety

OBJECTIVE

To evaluate the long-term outcomes of sentinel lymph node biopsy (SLNB) for head and neck cutaneous melanoma (HNCM).

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary academic medical center.

SUBJECTS AND METHODS

Longitudinal review of a 356-patient cohort with HNCM undergoing SLNB from 1997 to 2007.

RESULTS

Descriptive characteristics included the following: age, 53.5 ± 19 years (mean ± SD); sex, 26.8% female; median follow-up, 4.9 years; and Breslow depth, 2.52 ± 1.87 mm. Overall, 75 (21.1%) patients had a positive SLNB. Among patients undergoing completion lymph node dissection following positive SLNB, 20 (27.4%) had at least 1 additional positive nonsentinel lymph node. Eighteen patients with local control and negative SLNB developed regional disease, indicating a false omission rate of 6.4%, including 10 recurrences in previously unsampled basins. Ten-year overall survival (OS) and melanoma-specific survival (MSS) were significantly greater in the negative sentinel lymph node (SLN) cohort (OS, 61% [95% CI, 0.549-0.677]; MSS, 81.9% [95% CI, 0.769-0.873]) than the positive SLN cohort (OS, 31% [95% CI, 0.162-0.677]; MSS, 60.3% [95% CI, 0.464-0.785]) and positive SLN/positive nonsentinel lymph node cohort (OS, 8.4% [95% CI, 0.015-0.474]; MSS, 9.6% [95% CI, 0.017-0.536]). OS was significantly associated with SLN positivity (hazard ratio [HR], 2.39; P < .01), immunosuppression (HR, 2.37; P < .01), angiolymphatic invasion (HR, 1.91; P < .01), and ulceration (HR, 1.86; P < .01). SLN positivity (HR, 3.13; P < .01), angiolymphatic invasion (HR, 3.19; P < .01), and number of mitoses (P = .0002) were significantly associated with MSS. Immunosuppression (HR, 3.01; P < .01) and SLN status (HR, 2.84; P < .01) were associated with recurrence-free survival, and immunosuppression was the only factor significantly associated with regional recurrence (HR, 6.59; P < .01).

CONCLUSIONS

Long-term follow up indicates that SLNB showcases durable accuracy, safety, and prognostic importance for cutaneous HNCM.

Patterns of failure in patients with cutaneous head and neck melanoma

INTRODUCTION

The incidence of head and neck melanoma is increasing. Various factors influence prognosis.

OBJECTIVE

We sought to investigate the subgroup of patients with head and neck melanoma who fail primary treatment and to define the patterns of failure.

METHODS

The database of a tertiary medical center was reviewed for patients diagnosed and surgically treated for cutaneous head and neck melanoma in 1995-2014. Regional disease failure was defined as disease confirmed in positive SLNB at first assessment or at recurrence.

RESULTS

The cohort included 141 patients followed for a median duration of 6.8 years (range 1-20 years). Median tumor thickness was 2.1 mm (range 0.5-12 mm). Ulceration was documented in 38 patients (26.9%). Sentinel lymph node biopsy (SLNB) was positive in 18 patients (12.8%). Total disease failure rate was 32.6% with similar rates of regional (n = 26, 18.4%) and distal (n = 22, 15.6%) failure. Most patients (86.3%) with systemic recurrence had a negative SNLB as did 6/26 patients (23%) with regional failure. Forty-three patients (30.4%) died during follow-up, half of them (23 patients, 16.3%) of melanoma. On multivariate analysis, Breslow thickness was the only significant predictor of outcome.

CONCLUSIONS

The pattern of treatment failure in patients with head and neck melanoma relate predominantly to Breslow thickness. The high false-negative rate of SNLB and the relatively high rate of systemic failures in patients with negative SNLB indicate a low predictive value of this procedure. Efforts to detect systemic disease during follow-up need to be intensified.

Focused Ultrasound Surveillance of Lymph Nodes Following Lymphoscintigraphy Without Sentinel Node Biopsy: A Useful and Safe Strategy in Elderly or Frail Melanoma Patients

BACKGROUND

Sentinel node (SN) biopsy (SNB) has become standard of care in clinically localized melanoma patients. Although it is minimally invasive, advanced age and/or comorbidities may render SNB inadvisable in some patients. Focused ultrasound follow-up of SNs identified by preoperative lymphoscintigraphy may be an alternative in these patients. This study examines the outcomes in patients managed in this way at a major melanoma treatment center.

METHODS

All patients with clinically localized cutaneous melanoma who underwent lymphoscintigraphy and in whom SNB was intentionally not performed due to advanced age and/or comorbidities were included.

RESULTS

Between 2000 and 2009, 160 patients (5.2% of the total) underwent lymphoscintigraphy without SNB because of advanced age and/or comorbidities. Compared with the 2945 patients who had a SNB, the 160 patients were older, had thicker melanomas that were more often located in the head and neck region, and had more SNs in more nodal regions. Of the 160 patients, 150 (94%) were followed with ultrasound examination of their SNs at each follow-up visit; this identified 33% of the nodal recurrences before they became clinically apparent. Compared with SN-positive patients who were treated by completion lymph node dissection, observed patients who developed nodal recurrence had more involved nodes when a delayed lymphadenectomy was performed. Melanoma-specific survival, recurrence-free survival, and distant recurrence-free survival rates were similar, while regional lymph node-free survival was worse.

CONCLUSIONS

Lymphoscintigraphy with focused ultrasound follow-up of SNs is a reasonable management alternative to SNB in patients who are elderly and/or have substantial comorbidities.

Performance of a 31-gene expression profile test in cutaneous melanomas of the head and neck

Background

We report the performance of a gene expression profile test to classify the recurrence risk of cutaneous melanoma tumors of the head and neck as low‐risk Class 1 or high‐risk Class 2.

Methods

Of note, 157 primary head and neck cutaneous melanoma tumors were identified. Survival analyses were performed using Kaplan‐Meier and Cox methods.

Results

Gene expression profile class and node status stratified tumors into significantly different 5‐year survival groups by Kaplan‐Meier method (P < .0001 for all end points), and both were independent predictors of recurrence in multivariate analysis. Overall, 74% of distant metastases and 88% of melanoma‐specific deaths had Class 2 risk.

Conclusion

The gene expression profile test identifies cases at increased risk for metastasis and death independent of a clinically or pathologically negative nodal status, suggesting that incorporation of this molecular tool could improve clinical management of patients with head and neck cutaneous melanoma, especially in those with a negative sentinel lymph node biopsy.

Malignant Melanoma: Diagnostic and Management Update

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Summarize the changes to the American Joint Committee on Cancer Eighth Edition Melanoma Staging System. 2. List advances in genetic, molecular, and histopathologic melanoma diagnosis and prognostication. 3. Recommend sentinel lymph node biopsy and appropriate surgical margins based on individualized patient needs. 4. Recognize the currently available treatments for in-transit metastasis and advanced melanoma. 5. Describe current and future therapies for melanoma with distant visceral or brain metastases.

SUMMARY

Strides in melanoma surveillance, detection, and treatment continue to be made. The American Joint Committee on Cancer Eighth Edition Cancer Staging System has improved risk stratification of patients, introduced new staging categories, and resulted in stage migration of patients with improved outcomes. This review summarizes melanoma advances of the recent years with an emphasis on the surgical advances, including techniques and utility of sentinel node biopsy, controversies in melanoma margin selection, and the survival impact of time-to-treatment metrics. Once a disease manageable only with surgery, a therapeutic paradigm shift has given a more promising outlook to melanoma patients at any stage. Indeed, a myriad of novel, survival-improving immunotherapies have been introduced for metastatic melanoma and more recently in the high-risk adjuvant setting.

Updates in adjuvant systemic therapy for melanoma

There has been a rapid increase in adjuvant therapies approved for treatment following surgical resection of stages III/IV melanoma. We review current indications for adjuvant therapy, which currently includes a heterogenous group of stages III and IV patients with melanoma. We describe several pivotal clinical trials of systemic immune therapies, targeted immune therapies, and adjuvant vaccine strategies. Finally, we discuss the evidence for selecting the most appropriate treatment regimen(s) for the individual patient.

Complete lymphadenectomy following positive sentinel lymph node biopsy in cutaneous melanoma: a critical review

Cutaneous melanoma is the solid neoplasia with the highest growing incidence among all tumors. It spreads predictably to the lymphatic vessels and sentinel lymph node, and when the latter is affected the prognosis worsens dramatically. Sentinel lymph node biopsy is considered when thickness of the primary tumor exceeds 1mm and/or when there are adverse features in thinner melanomas. When there is nodal metastasis, current evidence in the literature recommends complete lymphadenectomy, although this procedure has its intrinsic risks (i.e., lymphedema and cellulitis), and there are no published clinical trials proving additional overall survival benefits. The current in-depth literature review thus aims to identify patients that will benefit most from the procedure, including those with the highest likelihood of presenting additional affected lymph nodes in the same nodal basin. The authors also discuss techniques for identification of the sentinel lymph node, false-negative rates, and predictive models for lymph node involvement. In conclusion, complete elective lymphadenectomy should always be discussed on a case-by-case basis when metastases are detected in the sentinel lymph node.

Tumour mutation status and melanoma recurrence following a negative sentinel lymph node biopsy

BACKGROUND

A proportion of patients develop recurrence following a tumour-negative sentinel lymph node biopsy (SLNB). This study aimed to explore whether melanoma patients with BRAF or NRAS mutant tumours have an increased risk of developing disease recurrence following a negative SLNB compared to patients with wild-type tumours.

METHODS

Prospective cohort study of melanoma patients at three tertiary referral centres in Melbourne, who underwent SLNB. Clinical, pathological and molecular characteristics and recurrence data were prospectively recorded. Multivariate Cox proportional hazards regression models estimated the adjusted hazard ratio (aHR) and corresponding 95% confidence interval (CI) for the association between mutation status and development of recurrence following a negative-SLNB.

RESULTS

Overall, 344/477 (72.1%) patients had a negative SLNB. Of these, 54 (15.7%) developed subsequent recurrence. The risk of disease recurrence following a negative SLNB was increased for patients with either a BRAF or NRAS mutant tumour compared to wild-type tumours (aHR 1.92, 95% CI: 1.02-3.60, p = 0.04).

CONCLUSION

Melanoma patients with BRAF or NRAS mutant tumours had an increased risk compared to patients with BRAF/NRAS wild-type tumours of developing disease recurrence following a tumour-negative SLNB. The findings also confirm the importance of continued surveillance to monitor for disease recurrence among SLNB-negative patients.

Predictors of false negative sentinel lymph node biopsy in trunk and extremity melanoma

BACKGROUND

Nodal recurrence following negative sentinel lymph node biopsy (SLNB) for melanoma is known as false-negative (FN) SLNB. Risk factors for FN SLNB among patients with trunk and extremity melanoma have not been well-defined.

METHODS

After retrospective review, SLNB procedures were classified FN, true positive (TP; positive SLNB), or true negative (TN; negative SLNB without recurrence). Factors associated with high false negative rate (FNR) and low negative predictive value (NPV) were identified by comparing FNs to TPs and TNs, respectively. Survival was evaluated using Kaplan-Meier methods.

RESULTS

Of 1728 patients, 234 were TP and 37 were FN for overall FNR of 14% and NPV of 97.5%. Age ≥65 years was independently associated with high FNR (FNR 20% in this group). Breslow thickness >1 mm and ulceration were independently associated with low NPV. Among patients with ulcerated tumors >4 mm, NPV was 88%. Median time to recurrence for FNs was 13 months. Among patients with primary melanomas ≤2 mm in depth, overall and distant disease-free survival were significantly shorter with FN SLNB than TP SLNB.

CONCLUSIONS

Older age is associated with increased FNR; patients with thick, ulcerated lesions should be considered for increased nodal surveillance after negative SLNB given low NPV in this group.

Sentinel Lymph Node Biopsy in Cutaneous Melanoma: Standard and New Technical Procedures and Clinical Advances. A Systematic Review of the Literature

Melanoma is an important public health problem, and its incidence is increasing worldwide. The disease status of regional lymph nodes is the most important prognostic factor in early-stage melanoma patients. Sentinel lymph node biopsy (SLNB) was introduced in the early 1990s as a less invasive procedure than complete lymph node dissection to allow histopathologic evaluation of the "sentinel lymph node" (SLN), which is the first node along the lymphatic pathway from a primary tumor. Sentinel lymph node biopsy has minimal complication risks compared with standard complete lymph node dissection. Currently, SLNB is the accepted method for staging patients with clinically node-negative cutaneous melanoma and provides the most powerful prognostic information by evaluating the nodal basin status. The current practice of SLNB consists of the injection of Tc-labeled radiopharmaceutical, preoperative lymphoscintigraphy with the possibility of using the SPECT/CT hybrid imaging, and intraoperative SLN localization using a handheld gamma probe with or without the use of blue dye. Recently, the SLN localization and detection have been enhanced with the use of new tracers and new intraoperative devices, which have demonstrated to be particularly useful in melanomas of the head and neck region and in area of complex anatomy. Despite these important advances in the technology and the increasing experience in SLN mapping, major research centers have reported a false-negative rate higher than 15%. This relatively high false-negative rate, greater than those reported in the initial validation studies, points out the importance for the nuclear medicine community to continuously improve their knowledge on the biological behavior of melanoma and to improve the technical aspects that may allow more precise staging. For the SLNB procedure to be accurate, it is of critical importance that all "true" SLNs are identified and removed for examination. The aim of this article is to provide general information about the SLNB procedure in clinical practice highlighting the importance of standardization and accuracy of SLN identification in the light of the most recent technical innovations.

Predictors and patterns of melanoma recurrence following a negative sentinel lymph node biopsy

To analyse the patient demographics, tumour characteristics and follow-up data of patients with recurrence of melanoma following a negative sentinel lymph node biopsy. A retrospective review of a prospectively maintained melanoma database was conducted. Melanoma patients who had a negative sentinel lymph node were identified and we performed statistical analysis on their respective demographics, tumour histology characteristics and follow-up data. Of 164 patients studied, 40 (24%) had a recurrence of melanoma at a median of 39.5 months following diagnosis (range 1-92 months). Distant metastases were the most common form of disease recurrence (40% of all recurrences). Increasing tumour thickness was an independent predictor of recurrence on multivariate analysis while nodular histology approached significance. Median survival of 6 months was seen following disease recurrence (range 1-126 months). In the setting of a negative sentinel lymph node biopsy, there remains a risk of melanoma recurrence. Distant metastases were the most common form of recurrence. Disease recurrence occurred more frequently in those with thick primary tumours. Recurrences occurred at long intervals from diagnosis indicating the need to consider prolonged patient follow-up.

Regression in thin melanoma is associated with nodal recurrence after a negative sentinel node biopsy

Prognostic markers for nodal metastasis in thin melanoma patients are debated. We present a single institution study looking at factors predictive of nodal disease in thin melanoma patients. Retrospective review from 1997 to 2012 identified 252 patients with thin melanoma (≤1 mm) who underwent a sentinel lymph node biopsy (SLNB). Node‐positive patients included positive SLNB patients and negative SLNB patients who developed a nodal recurrence (false‐negative SLNB). Clinicopathologic characteristics were correlated with nodal status and outcome. Median follow‐up was 45.5 months. Twelve of 252 patients (4.8%) were node‐positive including six positive SLNB (2.4%) and six false‐negative SLNB (2.4%) patients. No clinicopathologic factors were significantly correlated with nodal disease. For the six false‐negative SLNB patients, median time to nodal recurrence was 37.5 months. Regression was seen in only 16% of cases, but the rate increased to 60% for false‐negative SLNB cases. Both age (odds ratio [OR]: 1.09, 95% CI: 1.01–1.17; P = 0.02) and regression (OR: 8.33, 95% CI: 1.34–52.63; P = 0.02) were significantly associated with nodal recurrence after a negative SLNB on univariable analysis. Nodal disease in thin melanoma patients was seen in 4.8% of cases. Although regression was not correlated with nodal metastasis, it was correlated with a false‐negative SLNB. Patients with thin melanoma and regression may need more intensive surveillance after a negative SLNB. Further study is needed to determine if the same immune mechanisms that result in regression in primary tumors also lead to regression in lymph nodes, which may decrease detection of melanoma nodal metastases.

Sentinel node biopsy in patients with primary cutaneous melanoma of any thickness: A cost-effectiveness analysis

OBJECTIVE

To assess the cost-effectiveness of the sentinel node biopsy with lymphadenectomy for nodal metastases (SNB) in patients with primary cutaneous melanoma (CM) of different Breslow thickness (intermediate, thick, thin).

METHODS

Decision tree models were constructed to compare two different strategies of management of patients with CM, wide excision of the primary lesion and SNB and wide excision only (WE). Tree models were created for every Breslow thickness over 1-, 5- and 10-year time horizons. Mean and total direct healthcare costs, life years saved (LYSs), quality-adjusted life years (QALYs), cost effectiveness ratio (CER), and incremental cost effectiveness ratio (ICER) were estimated. Every model was considered as a base case, and its results tested with sensitivity analyses.

RESULTS

Base case analyses showed that the best results were obtained for intermediate CM over 10-year time horizon. In this case, ICER for SNB was 130,508€/QALY, well over the threshold of acceptance (30,000€/QALY). In patients with intermediate CM over 1 and 5 years, and for those with thick and thin CM at any time horizon, negative ICER values were estimated since SNB was proved to be more expensive and less effective than WE. Sensitivity analyses confirmed the robustness of our results.

CONCLUSIONS

SNB caused no improvement in health outcomes in terms of LYSs and QALYs in patients with thick and thin CM, and only a slight benefit in those with intermediate CM. WE was more cost-effective compared with SNB for any CM thickness over any time horizon up to 10 years.

SPECT/CT Improves Detection of Metastatic Sentinel Lymph Nodes in Patients with Head and Neck Melanoma

BACKGROUND

A positive sentinel lymph node (SLN) is the most important prognostic factor for predicting survival in cutaneous melanoma. This study aimed to evaluate how the addition of single-photon emission computed tomography (SPECT) and computed tomography (CT) to planar lymphoscintigraphy (PL) alters SLN identification, yield, and localization of metastatic nodes in head and neck melanoma.

METHODS

This retrospective review examined patients undergoing SLN biopsy for cutaneous melanoma of the head and neck between July 2003 and December 2015. Patient demographics and pathologic outcomes were compared for patients undergoing SPECT-CT versus PL. A multivariable logistic regression analysis was used to identify factors associated with the identification of a positive SLN.

RESULTS

Among 176 patients undergoing SLN biopsy, 91 underwent PL and 85 underwent SPECT-CT and PL. The patients in the SPECT-CT group were older than the PL patients (p = 0.050) but the groups did not differ in gender (p = 0.447), Breslow thickness (p = 0.744), or total number of SLNs identified (p = 0.633). As shown by the multivariate regression analysis, only Breslow thickness [odds ratio (OR) 1.47; 95 % confidence interval (CI) 1.17-1.84] and SPECT-CT (OR 3.58; 95 % CI 1.24-10.4) were associated with a positive SLN.

CONCLUSION

The use of SPECT-CT for patients with head and neck cutaneous melanoma significantly increases the likelihood of retrieving a positive SLN. Long-term follow-up evaluation is needed for further definition of the impact that SPECT-CT has on recurrence and survival.

Localization of the Sentinel Lymph Node in Melanoma Without Blue Dye

OBJECTIVE

The purpose of this study was to assess regional recurrence rates of patients who underwent sentinel lymph node biopsy (SLNB) using radiocolloid guidance alone.

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Lymph Node Micrometastases and In-Transit Metastases from Melanoma: In Vivo Detection with Multispectral Optoacoustic Imaging in a Mouse Model

Purpose To study whether multispectral optoacoustic tomography (MSOT) can serve as a label-free imaging modality for the detection of lymph node micrometastases and in-transit metastases from melanoma on the basis of the intrinsic contrast of melanin in comparison to fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT). Materials and Methods The study was approved by the institutional animal care and use committee. Sequential MSOT was performed in a mouse B16F10 melanoma limb lymph node metastasis model (n = 13) to survey the development of macro-, micro- and in-transit metastases (metastases that are in transit from the primary tumor site to the local nodal basin) in vivo. The in vitro limit of detection was assessed in a B16F10 cell phantom. Signal specificity was determined on the basis of a simultaneous lymphadenitis (n = 4) and 4T1 breast cancer lymph metastasis (n = 2) model. MSOT was compared with intravenous FDG PET/CT. The diagnosis was assessed with histologic examination. Differences in the signal ratio (metastatic node to contralateral limb) between the two modalities were determined with the two-tailed paired t test. Results The mean signal ratios acquired with MSOT in micrometastases (2.5 ± 0.3, n = 6) and in-transit metastases (8.3 ± 5.8, n = 4) were higher than those obtained with FDG PET/CT (1.1 ± 0.5 [P < .01] and 1.3 ± 0.6 [P < .05], respectively). MSOT was able to help differentiate even small melanoma lymph node metastases from the other lymphadenopathies (P < .05 for both) in vivo, whereas FDG PET/CT could not (P > .1 for both). In vitro, the limit of detection was at an approximate cell density of five cells per microliter (P < .01). Conclusion MSOT enabled detection of melanoma lymph node micrometastases and in-transit metastases undetectable with FDG PET/CT and helped differentiate melanoma metastasis from other lymphadenopathies. (©) RSNA, 2016 Online supplemental material is available for this article.

Prognostic factors in melanoma patients with tumor-negative sentinel lymph nodes

BACKGROUND

Sentinel lymph node (SLN) biopsy for melanoma results in accurate nodal staging, which guides treatment decisions. Patients with a negative SLN biopsy in general have a favorable prognosis, but certain subsets are at increased risk for recurrence and death. This study aimed to identify risk factors predictive of prognosis in patients with a tumor-negative SLN biopsy for cutaneous melanoma.

METHODS

In this post-hoc analysis of data from a multicenter prospective randomized trial, clinicopathologic data of patients with cutaneous melanoma ≥1.0 mm Breslow thickness and tumor-negative SLN were analyzed. Disease-free survival, overall survival (OS), and local and in-transit recurrence-free survival were compared by Kaplan-Meier analysis. Risk factors for worse survival were identified with Cox proportional hazard models.

RESULTS

This analysis included 1,998 patients with tumor-negative SLN with a median follow-up of 70 months. Ulceration, Breslow thickness, nonextremity tumor location, and age ≥45 years were independent risk factors for worse disease-free survival and OS. Breslow thickness and ulceration were the only factors on multivariate analysis that predicted local and in-transit recurrence-free survival. Estimated 5-year OS rates ranged from 55.5 to 95.4% on the basis of the defined risk factors.

CONCLUSION

There is a wide range of prognosis among patients with tumor-negative SLN. Breslow thickness, ulceration, age, and anatomic location of the primary melanoma are important independent factors predicting survival and recurrence among such patients. These factors can be used to stratify prognosis among patients with tumor-negative SLN to formulate rational long-term follow-up strategies as well as identify high-risk, SLN-negative patients for clinical trials of adjuvant therapy.

Predictors and Survival Impact of False-Negative Sentinel Nodes in Melanoma

BACKGROUND

The status of the sentinel lymph node in melanoma is an important prognostic factor. The clinical predictors and implications of false-negative (FN) biopsy remain debatable.

METHODS

We compared patients with positive sentinel lymph node biopsy (SNB) [true positive (TP)] and negative SNB with and without regional recurrence [FN, true negative (TN)] from our prospective institutional database.

RESULTS

Among 2986 patients (84 FN, 494 TP, and 2408 TN; median follow-up 93 months), the incidence of FN-SNB was 2.8%. While calculated FN rate was 14.5% [84 FN/(494 TP + 84 FN) × 100], when we accounted for local/in-transit recurrence (LITR) this rate was 8.5% [46 FN/(494 TP + 46 FN) × 100 %]. On multivariate analysis, male gender (OR 2.0, 95% CI 1.1-3.6, p = 0.018), head/neck primaries (OR 2.5, 95% CI 1.3-4.8, p < 0.006), and LITR (OR 3.5, 95% CI 2.1-5.8, p < 0.001) were associated with FN-SNB. Melanoma-specific survival (MSS) for the FN group was similar to the TP group at 5 years (68 vs. 73%, p = 0.539). However, MSS declined more for the FN group with a longer follow up and was significantly worse at 10 years (44 vs. 64%, p < 0.001). On multivariate analysis, FN-SNB was a significant predictor of worse MSS in melanomas <4 mm in Breslow thickness (HR 1.6; 95% CI 1.1-2.5, p = 0.021).

CONCLUSIONS

Male gender, LITR, and head and neck tumors were associated with FN-SNB. FN-SNB was an independent predictor of worse MSS in melanomas <4 mm in thickness, but this survival difference did not become apparent until after 5 years of follow-up.

Nodal Basin Recurrence After Sentinel Lymph Node Biopsy for Melanoma: A Retrospective Multicenter Study in 2653 Patients

The objective of this study was to analyze different types of nodal basin recurrence after sentinel lymph node biopsy (SLNB) for melanoma.

PATIENTS AND METHODS

Kaplan-Meier estimates and the Cox proportional hazards model were used to study 2653 patients from 3 German melanoma centers retrospectively.The estimated 5-year negative predictive value of SLNB was 96.4%. The estimated false-negative (FN) rates after 1, 2, 3, 5, and 10 years were 2.5%, 4.6%, 6.4%, 8.7%, and 12.6%, respectively. Independent factors associated with false negativity were older age, fewer SLNs excised, and head or neck location of the primary tumor. Compared with SLN-positive patients, the FNs had a significantly lower survival. In SLN-positive patients undergoing completion lymphadenectomy (CLND), the 5-year nodal basin recurrence rate was 18.3%. The recurrence rates for axilla, groin, and neck were 17.2%, 15.5%, and 44.1%, respectively. Significant factors predicting local relapse after CLND were older age, head, or neck location of the primary tumor, ulceration, deeper penetration of the metastasis into the SLN, tumor-positive CLND, and >2 lymph node metastases. All kinds of nodal relapse were associated with a higher prevalence of in-transit metastases.The FN rate after SLNB steadily increases over the observation period and should, therefore, be estimated by the Kaplan-Meier method. False-negativity is associated with fewer SLNs excised. The beneficial effect of CLND on nodal basin disease control varies considerably across different risk groups. This should be kept in mind about SLN-positive patients when individual decisions on prophylactic CLND are taken.

Analysis of melanoma recurrence following a negative sentinel lymph node biopsy

Little attention has been paid to the characteristics and outcomes of patients who experience distant, local or regional recurrence of melanoma following a negative sentinel lymph node biopsy. This article aims to review the published literature on the topic and presents some general summaries regarding this patient population. Patients who experience a disease recurrence following a negative sentinel lymph node biopsy have a worse overall survival compared with patients with a positive sentinel lymph node biopsy. The implications and possible explanations for these findings are discussed in order to both underscore the need for in-depth investigation of local, regional or distant melanoma recurrence among patients following a true negative sentinel lymph node biopsy, as well as increased efforts to minimize the rate of false negative sentinel lymph node biopsies.