Optimal Detection of Sentinel Lymph Node Metastases by Intraoperative Radioactive Threshold and Molecular Analysis in Patients with Melanoma

Abstract

The aim of this study was to optimize a protocol for radioguided biopsy of the sentinel lymph node (SLN) in patients with melanoma. The protocol was based on a combination of ex vivo counting of the nodes detected intraoperatively and analysis of the harvested nodes by hematoxylin and eosin staining plus immunohistochemistry (conventional histopathology [PATH]) and by molecular biology (reverse-transcriptase polymerase chain reaction [RT-PCR]). Methods: A total of 124 patients with primary clinical stage I-II (according to the American Joint Committee on Cancer) cutaneous melanoma underwent successful radioguided SLN biopsy. SLNs harvested for analysis included any additional nodes whose ex vivo counting rate exceeded 20% of the hottest node. All removed SLNs were examined by conventional PATH and with RT-PCR analysis for the expression of messenger RNA for tyrosinase and the melanoma antigens recognized by T cells. Complete lymph node dissection (CLND) was performed only in the case of SLN metastasis detected by PATH. Different combinations of the intraoperative parameters (only the hottest node and all nodes harvested) and of analysis (PATH and RT-PCR) were tested as predictors of clinical outcome on the basis of long-term follow-up (12-81 mo; median, 55 mo). Results: A total of 197 SLNs were harvested, 41 of which harbored metastasis as detected by RT-PCR analysis; PATH detected metastasis in only 24 of 41 metastatic SLNs. In 5 of 41 instances, metastasis was not in the hottest SLN. The main factor determining correct classification of the SLN status was RT-PCR, which significantly improved detection of metastasis, even if applied only to the hottest node (P , 0.0001 vs. PATH analysis of either the hottest SLN or all nodes above the 20% threshold). Metastatic disease recurred locally in 5 patients who had not undergone CLND; RT-PCR analysis showed metastasis in 4 of these patients. The false-negative rate of SLN biopsy progressively decreased when applying PATH only to the hottest node (32.1%), additional RT-PCR to the hottest node (21.4%), PATH to all nodes (17.9%), and RT-PCR to all nodes (3.6%, P 5 0.015 vs. PATH analysis of only the hottest SLN). Conclusion: On the basis of long-term follow-up (the gold standard for final clinical outcome of SLN biopsy), both 20% threshold and RT-PCR analysis should be applied for optimal detection of nodal metastases in patients with melanoma.

Meta-analysis of completion lymph node dissection in sentinel lymph node-positive melanoma

“…A further five studies were excluded because they either had a missing intervention or control group, or the population of interest was not studied. After review, 15 articles were included in the qualitative synthesis ( Fig . ).…”

“…Two cohort studies were excluded from the meta‐analysis after failing the NOS tool bias analysis for lack of comparability of groups. The remaining 13 studies (11 cohort studies and 2 RCTs) were found to be suitable for analysis ( Fig.…”

Lymphatic Path of the Inguinal Lymph Node Metastases in Anorectal Cancer

“…In other malignant tumors, such as breast cancer or melanoma where SLN biopsy is also widely applied, the lymphatic path is not always assessed, and it is usually not included in the resected specimen. 8,9 In tumors of the anal canal that exceed the dentate line though, the excision of the anoinguinal lymphatic path, which corresponds to the inguinal crease, is indicated because it carries a significant malignant cellular load, otherwise treated with local radiotherapy. 10 The springbok pattern puts on the map the aggregate of local metastasis in anal cancer and leads the surgeon to include the related lymphatic path in the inguinal SLN dissection.…”

Lymphoscintigraphy and clinic

“…Lymphatic mapping using radio colloid reveals ways unexpected of lymphatic drainage, it finds all the stations limph node at a greater risk of metastasis and for each of them, locates the sentinel lymph node; it also allows the identification and biopsy of the lymph nodes in-transit (the lymph nodes under the skin spots between the seat skin of the melanoma and the station lymph node Res Rev Insights, 2017 doi: 10.15761/RRI.1000105 main) [49,50]. With the new generation of large -field of view gamma cameras, SPECT/TC has been incorporated in the SLN procedure.…”