Efficacy of indocyanine green fluoroscopy for sentinel node biopsy in head and neck melanoma: a systematic review and meta-analysis

The objective of this review was to conduct a systematic review and meta-analysis on the efficacy of ICG (indocyanine green) for sentinel lymph node (SLN) detection in head and neck melanoma. The Preferred Reporting Items for Systematic reviews and Meta-Analyses statement standards (PRISMA) were followed when conducting this review with a comprehensive search of the following online databases; Google Scholar, PubMed, MEDLINE, CINAHL, and CENTRAL, World Health Organization International Clinical Trials Registry (http://apps.who.int/trialsearch/), ClinicalTrials.gov (http://clinical-trials.gov/), and the ISRCTN registry (http://www.isrctn.com/). Nine studies met the inclusion criteria and results were reported with forest plots at 95% confidence intervals. Primary outcomes of interest included the localisation rate for sentinel node biopsies in head and neck melanoma using ICG and compared with other adjunct modalities. Secondary outcome measures included false negative rates as well as sensitivity rates for nodal detection with radiocolloid as well as blue dye. ICG reported an overall sensitivity rate of 95% with an untransformed proportion metric analysis (0.950, 0.922, 0.978 (95% CI)). It demonstrated a superior detection rate to blue dye (Odds ratio 15.417, 95% CI, 4.652 to 51.091, p < 0.001) and a comparable localisation efficacy to radiocolloid (Odds ratio 1.425, 95% CI, 0.535 to 3.794, p = 0.478). The sensitivity rate for radiocolloid utilisation in isolation was 90.6% (untransformed proportion metric, 0.906, 0.855, 0.957) and blue dye was 48.7% (untransformed proportion metric, 0.487, 0.364, 0.610). This is the first meta-analysis on the efficacy of ICG for sentinel node detection in head and neck melanoma. The authors advocate for a dual modality approach with ICG and radiocolloid to mitigate the inherent limitations of both methods when conducting sentinel node retrieval for head and neck melanoma. Further high-quality randomised trials are needed to improve the current evidence base.

Detection of Sentinel Lymph Nodes Using Indocyanine Green After Failing Scintigraphy in Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare but highly aggressive skin cancer that carries a high rate of lymph node involvement and death. The National Comprehensive Cancer Network recommends sentinel lymph node (SLN) biopsy for the staging of the disease. Scintigraphy using radioactive isotopes (RI) such as technetium 99m (Tc99) remains the gold standard for the detection of SLNs, however, recently indocyanine green (ICG) fluorescence imaging has been used to aid in the detection of SLNs.We present the case of a patient who presented with MCC of the face and two SLNs successfully identified with ICG fluorescence despite the fact that they were not detected by intraoperative scintigraphy using Tc99. The use of ICG fluorescence imaging in MCC is safe and improves the ability to detect SLNs when combined with RI.

Sentinel Lymph Node Procedure in Pediatric Patients with Melanoma, Squamous Cell Carcinoma, or Sarcoma Using Near-Infrared Fluorescence Imaging with Indocyanine Green: A Feasibility Trial

BACKGROUND

Standard sentinel lymph node procedure (SNP) in pediatric cancer consists of a preoperative injection with ^99mtechnetium nanocolloid in combination with an optional intraoperative injection with blue dye. However, blue dye has disadvantages, and the detection rate is low, with only 60% of sentinel lymph nodes (SLNs) staining blue. In adult oncology, fluorescence imaging using indocyanine green (ICG) has been shown to be a safe and accurate method for visual detection of SLNs, with a higher sensitivity (up to 97%) compared with blue dye. Therefore, our aim is to determine the feasibility of the addition of ICG to ^99mtechnetium nanocolloid (ICG-TC) for visual detection of SLN in pediatric patients.

METHODS

A total of 15 pediatric patients with melanoma, squamous cell carcinoma, and sarcoma were prospectively included. Preoperatively, patients were injected with ICG-TC and imaging with lymphoscintigraphy and single-photon emission computed tomography- computed tomography was performed. Intraoperatively, SLN was detected with fluorescence and the gamma probe. Postoperatively, fluorescence was quantified by tumor-to-background ratio (TBR) and surgeons evaluated the use of ICG using a standardized questionnaire.

RESULTS

In 10/15 (67%) patients, SLNs were visible transcutaneously. Of all intraoperatively detected SLNs, 35/37 (95%) were fluorescent and 37/37 (100%) were radioactive. Furthermore, ICG-TC led to the identification of six additional SLNs as compared with preoperative imaging. The median TBR in vivo was 6.5 (IQR 5.3). The surgical evaluation showed that ICG assisted in SLN detection and was easy to use.

CONCLUSIONS

ICG-TC for the SNP is a feasible procedure in pediatric patients. It showed an accurate detection rate, was helpful for visual guidance, and no adverse events occurred.

Technologic (R)Evolution Leads to Detection of More Sentinel Nodes in Patients with Melanoma in the Head and Neck Region

Sentinel lymph node (SN) biopsy (SNB) has proven to be a valuable tool for staging melanoma patients. Since its introduction in the early 1990s, this procedure has undergone several technologic refinements, including the introduction of SPECT/CT, as well as radioguidance and fluorescence guidance. The purpose of the current study was to evaluate the effect of this technologic evolution on SNB in the head and neck region. The primary endpoint was the false-negative (FN) rate. Secondary endpoints were number of harvested SNs, overall operation time, operation time per harvested SN, and postoperative complications. Methods: A retrospective database was queried for cutaneous head and neck melanoma patients who underwent SNB at The Netherlands Cancer Institute between 1993 and 2016. The implementation of new detection techniques was divided into 4 groups: 1993-2005, with preoperative lymphoscintigraphy and intraoperative use of both a γ-ray detection probe and patent blue (n = 30); 2006-2007, with addition of preoperative road maps based on SPECT/CT (n = 15); 2008-2009, with intraoperative use of a portable γ-camera (n = 40); and 2010-2016, with addition of near-infrared fluorescence guidance (n = 192). Results: In total, 277 patients were included. At least 1 SN was identified in all patients. A tumor-positive SN was found in 59 patients (21.3%): 10 in group 1 (33.3%), 3 in group 2 (20.0%), 6 in group 3 (15.0%), and 40 in group 4 (20.8%). Regional recurrences in patients with tumor-negative SNs resulted in an overall FN rate of 11.9% (group 1, 16.7%; group 2, 0%; group 3, 14.3%; group 4, 11.1%). The number of harvested nodes increased with advancing technologies (P = 0.003), whereas Breslow thickness and operation time per harvested SN decreased (P = 0.003 and P = 0.017, respectively). There was no significant difference in percentage of tumor-positive SNs, overall operation time, and complication rate between the different groups. Conclusion: The use of advanced detection technologies led to a higher number of identified SNs without an increase in overall operation time, possibly indicating an improved surgical efficiency. Operation time per harvested SN decreased; the average FN rate remained 11.9% and was unchanged over 23 y. There was no significant change in postoperative complication rate.

The utility of ICG fluorescence for sentinel lymph node identification in head and neck melanoma

PURPOSE

Perform an evidence-based review to determine the utility of indocyanine green fluorescence (ICG) to detect sentinel lymph nodes (SLN) in patients with head and neck melanoma compared to blue dye or radiocolloid injection (RI).

MATERIALS AND METHODS

A systematic review of the literature was performed to identify patients with head and neck melanoma managed with ICG fluorescence. PubMed, Embase, and Cochrane Library databases were searched. Included studies were assessed for level of evidence. Patient demographics and data on SLN identification were determined.

RESULTS

Twenty-two studies encompassing 399 patients (75% male, 25% female, average age 57.1 years) met inclusion criteria. Publications comprised of two case reports, four retrospective case series, twelve cohort studies, and four clinical trials. Most common site of melanoma was scalp/temple/forehead (35%), cheek/midface (22%), and ear (17%) with an average Breslow thickness of 3.32 mm. SLN was identified in 80.7% (n = 201/249) of patients using ICG-RI, 85.2% (n = 75/88) using RI alone, and 63.4% (n = 52/82) using blue dye-RI.

CONCLUSIONS

ICG-^99mTc-nanocolloid hybrid tracer may be a superior alternative to blue dye + adiocolloid and has theoretical advantages compared to RI alone. Additional prospective randomized controlled trials are needed to further compare these methods and obtain data on false negative rates, operating room time, and cost effectiveness to fully elucidate the utility of ICG-^99mTc-nanocolloid over current methods used for SLN identification in this patient population.