Lymphoscintigraphy Using Tilmanocept Detects Multiple Sentinel Lymph Nodes in Melanoma Patients.

BACKGROUND: Technetium-99m-labeled Tilmanocept, a multivalent mannose, is readily internalized by the CD206 surface receptor on macrophages and dendritic cells which are abundantly present in lymph nodes. We want to examine the drainage patterns of Technetium-99m-labeled Tilmanocept to sentinel lymph nodes (SLNs) in melanoma patients following the 10% rule. METHODS: Multi-center retrospective review of patients with cutaneous melanoma undergoing SLN biopsy using Technetium-99m-labeled Tilmanocept between 2008 and 2014 was conducted. Statistical methods were used for data analyses. RESULTS: Of the 564 patients (mean age of 60.3 and 62% male) with preoperative lymphoscintigraphy showing at least one SLN, several primary tumor sites were included: 27% head/neck, 33% trunk, 21% upper extremity and 19% lower extremity. For the head/neck primary site, 36.5% of patients had multiple draining basins; for the trunk site, 36.4% of patients; for the upper extremity site, 13% of patients; and for the lower extremity, 27.4% of patients. A median of 3 (range 1-18) SLNs were identified and resected. Overall, 78% of patients had >1 SLN identified by Technetium-99m-labeled Tilmanocept. In a multivariate model, patients with >1 SLN were significantly associated with age, Breslow depth, tumor location and higher AJCC tumor stage. A total of 17.7% of patients (100/564) had a positive SLN identified. A total of 145 positive SLNs were identified out of 1,812 SLNs with a positive SLN rate of 8%. Positive SLN status was significantly associated with younger age, greater Breslow depth, mitosis rate, higher AJCC tumor stage, presence of ulceration and angiolymphatic invasion. CONCLUSIONS: Using the 10% rule, Technetium-99m-labeled Tilmanocept detects multiple SLNs in most melanoma patients.

Correction to: Intraoperative Imaging with a Portable Gamma Camera May Reduce the False-Negative Rate for Melanoma Sentinel Lymph Node Surgery.

The article "Intraoperative Imaging with a Portable Gamma Camera May Reduce the False-Negative Rate for Melanoma Sentinel Lymph Node Surgery," written by Stanley P. Leong et al., was originally published electronically on the publisher's internet portal (currently SpringerLink) on August 13, 2018, without open access.

Intraoperative Imaging with a Portable Gamma Camera May Reduce the False-Negative Rate for Melanoma Sentinel Lymph Node Surgery.

BACKGROUND: Preoperative imaging and intraoperative gamma probe (GP) localization is standard for identifying sentinel lymph nodes (SLNs) in melanoma patients. The aim of this prospective Institutional Review Board-approved study was to investigate whether an intraoperative portable gamma camera (PGC) improves SLN detection over the GP. METHODS: Lymphoscintigraphy and single photon emission computed tomography/computed tomography were performed after injection of 99mTc-Tilmanocept in melanoma patients (≥ 18 years, Breslow thickness ≥ 1.0 mm). A GP was used to localize the SLNs in each basin, which was explored by the GP to ensure that the operative field was < 10% counts of the hottest SLN. The PGC was then used after a negative GP screening. Any residual hotspots identified by the PGC were considered as additional SLNs and were removed following the 10% rule. RESULTS: Preoperative imaging of 100 patients identified 138 SLN basins, with 306 SLNs being identified by conventional surgery. The PGC localized 89 additional SLNs in 54 patients. Thus, the PGC identified an additional 23% of SLNs [95% confidence interval (CI) 18-27%]. Four of these 89 SLNs showed micrometastasis in four patients, in two of whom the only tumor-positive SLN was identified by the PGC, preventing two false-negative cases. Thus, the null hypothesis that the PGC did not detect additional positive SLNs was rejected (p = 0.000). The overall SLN positive rate was 9.9% (39/395, 95% CI 6-12), and the overall patient positive rate was increased using the PGC, from 25 to 27% (27/100). CONCLUSIONS: Intraoperative PGC imaging yielded additional SLNs in a significant number of patients over GP alone. Identification of these additional SLNs resulted in upstaging of four patients with two patients being converted from a negative to a positive status, thus, preventing two false-negative cases.

Preoperative and Intraoperative Identification of Sentinel Lymph Nodes in Melanoma Surgery.

According to the American Joint Commission on Cancer (AJCC) 8th edition guidelines, SLN biopsy is recommended for primary melanomas with a Breslow thickness of at least 1 mm. Additionally, the National Comprehensive Cancer Network (NCCN) recommends that a SLN biopsy may be considered for melanoma patients with T1b lesions, which are 0.8-1 mm thick or less than 0.8 mm thick with ulceration. It can also be considered for T1a lesions that are less than 0.8 mm thick but have other adverse features, such as a high mitotic rate, lymphovascular invasion, or a positive deep margin. To reduce the false negative rate of melanoma SLN biopsy, we have introduced the intraoperative use of Sentinella, a gamma camera, to enhance the identification rate of SLNs beyond that of the traditional gamma hand-held probe. At the Center for Melanoma Research and Treatment at the California Pacific Medical Center, a multidisciplinary approach has been established to treat melanoma patients when the diagnosis of primary melanoma is made with a referral to our melanoma center. This comprehensive approach at the melanoma tumor board, including the efforts of pathologists, radiologists, dermatologists, surgical, medical and radiation oncologists, results in a consensus to deliver personalized and high-quality care for our melanoma patients. This multidisciplinary program for the management of melanoma can be duplicated for other types of cancer. This article consists of current knowledge to document the published methods of identification of sentinel lymph nodes. In addition, we have included new data as developed in our melanoma center as newly published materials in this article to demonstrate the utility of these methods in melanoma sentinel lymph node surgery. Informed consent has been waived by our IRB regarding the acquisition of clinical data as presented in this study.