489 The Role of Sentinel Lymph Node Biopsy in Cutaneous Head and Neck Melanoma: A Systematic Review and Meta-Analysis

Introduction and Aims The aim of this systematic review is to provide an up-to-date evaluation of the role and test performance of sentinel lymph node biopsy (SLNB) in the head and neck. Method This review follows the PRISMA guidelines. Database searches for MEDLINE and EMBASE were constructed to retrieve human studies published between 1st January 2010 and 1st July 2020 assessing the role and accuracy of sentinel lymph node biopsy in cutaneous malignant melanoma of the head and neck. Articles were independently screened by two reviewers and critically appraised using the MINORS criteria. The primary outcomes consisted of the sentinel node identification rate and test-performance measures, including the false-negative rate and the posttest probability negative. Results A total of 27 studies, including 4688 patients, met the eligibility criteria. Statistical analysis produced weighted summary estimates for the sentinel node identification rate of 97.3% (95% CI, 95.9% to 98.6%), the false-negative rate of 21.3% (95% CI, 17.0% to 25.4%) and the posttest probability negative of 4.8% (95% CI, 3.9% to 5.8%). Discussion Sentinel lymph node biopsy is accurate and feasible in the head and neck. Despite technical improvements in localisation techniques, the false negative rate remains disproportionately higher than for melanoma in other anatomical sites.

Meta-analysis Comparing Fluorescence Imaging with Radioisotope and Blue Dye-Guided Sentinel Node Identification for Breast Cancer Surgery

Introduction Conventional methods for axillary sentinel lymph node biopsy (SLNB) are fraught with complications such as allergic reactions, skin tattooing, radiation, and limitations on infrastructure. A novel technique has been developed for lymphatic mapping utilizing fluorescence imaging. This meta-analysis aims to compare the gold standard blue dye and radioisotope (BD-RI) technique with fluorescence-guided SLNB using indocyanine green (ICG). Methods This study was registered with PROSPERO (CRD42019129224). The MEDLINE, EMBASE, Scopus, and Web of Science databases were searched using the Medical Subject Heading (MESH) terms ‘Surgery’ AND ‘Lymph node’ AND ‘Near infrared fluorescence’ AND ‘Indocyanine green’. Studies containing raw data on the sentinel node identification rate in breast cancer surgery were included. A heterogeneity test (using Cochran’s Q) determined the use of fixed- or random-effects models for pooled odds ratios (OR). Results Overall, 1748 studies were screened, of which 10 met the inclusion criteria for meta-analysis. ICG was equivalent to radioisotope (RI) at sentinel node identification (OR 2.58, 95% confidence interval [CI] 0.35–19.08, p < 0.05) but superior to blue dye (BD) (OR 9.07, 95% CI 6.73–12.23, p < 0.05). Furthermore, ICG was superior to the gold standard BD-RI technique (OR 4.22, 95% CI 2.17–8.20, p < 0.001). Conclusion Fluorescence imaging for axillary sentinel node identification with ICG is equivalent to the single technique using RI, and superior to the dual technique (RI-BD) and single technique with BD. Hospitals using RI and/or BD could consider changing their practice to ICG given the comparable efficacy and improved safety profile, as well as the lesser burden on hospital infrastructure.

Sentinel Node Identification in Melanoma: Current Clinical Impact, New Emerging SPECT Radiotracers and Technological Advancements. An Update of the Last Decade

Background: Melanoma is the most lethal skin cancer with a mortality rate of 262 cases per 100.000 cases. The sentinel lymph node (SLN) is the first lymph node draining the tumor. SLN biopsy is a widely accepted procedure in the clinical setting since it provides important prognostic information, which helps patient management, and avoids the side effects of complete lymph node dissection. The rationale of identifying and removing the SLN relies on the low probability of subsequent metastatic nodes in case of a negative histological exam performed in the SLN. Discussion: Recently, new analytical approaches, based on the evaluation of scintigraphic images are also exploring the possibility to predict the metastatic involvement of the SLN. 99mTc-labeled colloids are still the most commonly used radiotracers but new promising radiotracers, such as 99mTc- Tilmanocept, are now on the market. In the last decades, single photon emission computed tomography- computerized tomography (SPECT/CT) has gained wider diffusion in clinical departments and there is large evidence about its superior diagnostic accuracy over planar lymphoscintigraphy (PL) in the detection of SLN in patients with melanoma. Scientists are also investigating new hybrid techniques combining functional and anatomical images for the depiction of SLN but further evidence about their value is needed. Conclusion: This review examined the predictive and prognostic factors of lymphoscintigraphy for metastatic involvement of SLN, the currently available and emerging radiotracers and the evidence of the additional value of SPECT/CT over PL for the identification of SLN in patients with melanoma. Finally, the review discussed the most recent technical advances in the field.

Can Sentinel Lymph Node Biopsy Predict Various Levels of Echelon Nodes in Oral Cancers?

Introduction The efficacy of sentinel node biopsy in early stage oral cancer is well established. Its evolving role can be reinforced by further studies. Objective Analyzing the predictability of the levels of echelon nodes for various oral cavity tumor subsites on sentinel node biopsy. Methods A prospective study of 20 patients with stage I/II oral squamous cell carcinoma who underwent sentinel node biopsy-guided neck dissection between January 2017 and 2018 at our institute. The procedure included radiotracer injection, imaging (lymphoscintigraphy, single photon emission computed tomography-computed tomography), and gamma probe application. Sentinel node detection on imaging and gamma probe were compared. Results Out of 20 patients, 13 (65%) had carcinoma of the tongue, 6 (30%) had buccal mucosa carcinoma, and 1 (5%) had retromolar trigone carcinoma. The mean age of the patients was 52.3 years. A total of 13 (65%) patients were male, and 7 (35%) were female. The sentinel node identification rates with imaging and gamma probe were of 70% and 100% respectively. In tongue and retromolar trigone primaries, the most common first-echelon nodes in both modalities were levels IIA and IB respectively. For buccal mucosa primaries, first-echelon nodes were detected only with the gamma probe, which was level IB. On imaging, second-echelon nodes were detected only for tongue primaries, and had equivalent incidence of levels II, III, and IV. On the gamma probe, level IIA, followed by III, and IV for the tongue, and level IIA were the most common second-echelon nodes for the buccal mucosa. Third-echelon nodes were detected only with the gamma probe for tongue carcinoma at level IV. Conclusion The combined use of imaging and gamma probe provides the best results, with high identification rate and predictability of echelon levels.