Tips and tricks to improve sentinel lymph node mapping with Indocyanin green in endometrial cancer

Predictors for sentinel lymph node mapping failure using indocyanine green injection in apparent early stages of endometrial cancer: A single-center prospective study

OBJECTIVE

The current study aimed to analyze predictive factors of sentinel lymph node mapping failure in apparently early stages of endometrial cancer using intracervical indocyanine green injection.

METHODS

A single-center prospective study was conducted between June 2019 and August 2023 at the Department of Gynecology and Obstetrics, University Hospital Brno, Czech Republic. All patients with apparently early stage (I or II according to FIGO [International Federation of Gynecology & Obstetrics] 2009) endometrial cancer, who were indicated for sentinel node biopsy were consecutively included. The injection of 4-6 mL of indocyanine green was applied superficially and deeply into cervical tissue at the 3- and 9-o'clock positions. Patients' clinical data, surgical characteristics, and histopathological information were recorded. Univariable and multivariable regression analyses were applied.

RESULTS

A total of 225 patients were eligible during the study period. Considering bilateral and unilateral failed mapping together, the only statistically significant factors for risk of failure in univariable analysis were body mass index (BMI; P = 0.036), FIGO 2009 stage (P = 0.019), and the presence of a myoma (P = 0.017). Nevertheless, when the multivariable logistic regression analysis was applied, all factors became statistically insignificant except for myoma (P = 0.031). Regarding only bilateral mapping failure, in univariable analysis, BMI (P = 0.021) and FIGO 2009 stage (P = 0.046) were significant predictors of failure. Interestingly, multivariable logistic regression analysis revealed that in addition to BMI (P = 0.007), age (P = 0.004) was also an independent predictor of bilateral failure.

CONCLUSIONS

Higher BMI and age were statistically significant independent factors for bilateral sentinel node mapping failure in early-stage endometrial cancer.

The Assessment of Sentinel Lymph Node Mapping Methods in Endometrial Cancer

Background/Objectives: Sentinel lymph node biopsy (SLNB) is a minimally invasive technique used to assess lymphatic involvement in endometrial cancer (EC), offering reduced surgical morbidity compared to routine lymphadenectomy. Despite its widespread use, the optimal combination of tracers for SLN detection remains a subject of debate. Methods: This retrospective cohort study included 119 patients with early-stage EC treated at the Maria Skłodowska-Curie National Research Institute of Oncology between 2016 and 2021. SLNB was performed using technetium-99m (Tc99m), indocyanine green (ICG), Patent Blue, or combinations of these tracers. Detection rates for unilateral and bilateral SLNs and the accuracy of metastasis identification were analyzed. Results: The overall SLN detection rate was 97.5%. Individual tracer detection rates were 100% for ICG, 100% for Patent Blue, and 96% for Tc99m. Combined tracers achieved detection rates of 96.9% (Tc99m and ICG) and 97.3% (Tc99m and Patent Blue). Bilateral detection was highest with Tc99m and ICG (90.6%) and Patent Blue alone (91%). Metastases were identified in 12% of cases, with combined methods improving metastatic detection. Tc99m yielded no "empty nodes", compared to 1.7% with Patent Blue and 0.8% with ICG. Conclusions: While combining Tc99m with dyes did not significantly improve overall SLN detection rates, it enhanced metastatic identification and reduced false-negative results. These findings suggest that combined tracer methods optimize SLNB accuracy in endometrial cancer. Prospective studies are needed to confirm these results.

Indocyanine green in gynecologic surgery: Where do we stand? A literature review and meta-analysis

The main objective of this study was to review and perform a meta-analysis of current literature on the use of indocyanine green for sentinel lymph node detection in pelvic gynecologic cancer. We included all studies focusing on indications and procedures associated with the use of ICG in gynecologic surgery and available on the Medline and Pubmed database. For the meta-analysis, random effect models were used for estimation of the 95 % detection rate and 95 % confidence interval, and stratified analyses by cancer type, concentration and localization of injection were performed. A total of 147 articles were included, of which 91 were studied in a meta-analysis. Results concerning detection rate by indocyanine green injection site were found to be 95.1 % and 97.3 % respectively for intracervical injection in 2 or 4 quadrants, and 77.0 % and 94.8 % for hysteroscopic and intradermal injection respectively. Results concerning detection rate by cancer type were 95.8 %, 95.2 %, 94.7 % and 95.7 % respectively for cervical, endometrial, vulvar and endometrial/cervical cancers. Finally, the results concerning detection rate by indocyanine green concentration were 91.2 %, 95.7 %, 96.7 % and 97.7 % for concentrations of <1.25 mg/ml, 1.25 mg/ml, 2.5 mg/ml and 5 mg/ml respectively. In conclusion, indocyanine green is shown to allow highlighting of sentinel lymph nodes with good reliability with an overall indocyanine green detection rate of 95.5 %. Our literature review revealed that indocyanine green feasibility has also been demonstrated in several surgical contexts, notably for reconstructive surgery and detection of endometriosis.

Analysis of Predictive Factors Associated with Unsuccessful Sentinel Lymph Node Mapping in Endometrial Carcinoma

BACKGROUND

Sentinel lymph node (SLN) biopsy is recommended over systematic lymphadenectomy in early-stage endometrial cancer due to its lower morbidity and comparable detection rate. The objective of this study was to identify clinical factors associated with unsuccessful mapping.

METHODS

Between April 2020 and June 2024, 120 patients over the age of 18 and diagnosed with early-stage endometrial cancer were enrolled in this prospective study at a single institution. Demographic, clinicopathologic, and treatment data were collected and analyzed using descriptive statistics. Univariate and multiple linear regressions were performed to identify predictors of failed mapping.

RESULTS

The mean age of the patient cohort was 62.5 years (range 33 to 83), and the mean body mass index (BMI) was 32 kg/m2 (range 18 to 50). Patients underwent intracervical injections with methylene blue (MB), indocyanine green (ICG), or a combination of both tracers, with 40 patients in each group. A total of 108 patients (90.0%) were diagnosed with endometrioid carcinoma and 12 (10.0%) with non-endometrioid cancers. Additionally, 110 patients (91.7%) were diagnosed in early stages of the disease. The overall SLN detection rate was 73.4%, with bilateral detection at 49.2% and unilateral detection at 24.2%. Univariate analysis showed that older age (p < 0.001), menopause (p = 0.001), the use of MB as the sole tracer (p = 0.006), a shorter tumor-to-serosa distance (p = 0.048), and bulky lymph nodes (p = 0.18) were associated with unsuccessful mapping. Multiple linear regression model analysis identified age (p = 0.007), tracer type (p = 0.013), and enlarged lymph nodes (p = 0.013) as independent predictors of SLN mapping failure.

CONCLUSIONS

Advanced age, tracer type, and intraoperative detection of enlarged lymph nodes were identified as independent risk factors for unsuccessful mapping in patients undergoing laparoscopic SLN mapping.

Sentinel Lymph Node Assessment in Endometrial Cancer: A Review

As the number of patients diagnosed with endometrial cancer rises, so does the number of patients who undergo surgical treatment, consisting of radical hysterectomy, bilateral salpingo-oophorectomy, and bilateral pelvic lymphadenectomy or lymph node sampling. The latter entail intra- and post-surgical complications, such as lymphedema and increased intra-operative bleeding, which often outweigh their benefits. Sentinel Lymph Node (SLN) sampling is now common practice in surgical management of breast cancer, as it provides important information about the disease without jeopardizing surgical radicality and patient outcomes. While this technique has also been shown to be feasible in patients with endometrial cancer, there is little consensus on several aspects, such as tracer injection volume and site, pathological ultrastaging, and result interpretation. The aim of this review is to analyze the current literature on SLN assessment in order to help standardize the procedure.

Pelvic Sentinel Lymph Node Biopsy for Endometrial Cancer with Multi-Modal Infrared Signal Technology: A Video Article

This video article summarizes a case study involving the use of pelvic sentinel lymph node (SLN) biopsy for endometrial cancer (EC) staging and treatment utilizing a multi-modal infrared signal technology. This innovative approach combines cervical injection of fluorescent dye indocyanine green (ICG) and near-infrared imaging to enhance SLN detection rates in early-stage EC patients. The study showcases the successful application of advanced technology in improving surgical staging procedures and reducing postoperative morbidity for patients. Multi-modal infrared signal technology consists of different modes of fluorescence imaging used to identify lymph nodes based on near-infrared signals. Each mode serves a specific purpose: overlay image combines white light and near-infrared signals in green, monochromatic visualization shows near-infrared signal in greyscale, and intensity map combines signals in a color scale to differentiate signal intensity. Yellow denotes strong near-infrared signals while blue represents weaker signals. By utilizing a multi-modal approach, surgeons can accurately identify and remove SLN, thus avoiding unnecessary removal of secondary or tertiary echelons.

Risk factors associated with false negative rate of sentinel lymph node biopsy in endometrial cancer: a systematic review and meta-analysis

Objective

Currently, sentinel lymph node biopsy (SLNB) is increasingly used in endometrial cancer, but the rate of missed metastatic lymph nodes compared to systemic lymph node dissection has been a concern. We conducted a systematic review and meta-analysis to evaluate the false negative rate (FNR) of SLNB in patients with endometrial cancer and to explore the risk factors associated with this FNR.

Data sources

Three databases (PubMed, Embase, Web of Science) were searched from initial database build to January 2023 by two independent reviewers.

Research eligibility criteria

Studies were included if they included 10 or more women diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage I or higher endometrial cancer, the study technique used sentinel lymph node localization biopsy, and the reported outcome metrics included false negative and/or FNR.

Study appraisal and synthesis methods

Two authors independently reviewed the abstracts and full articles. The FNR and factors associated with FNR were synthesized through random-effects meta-analyses and meta-regression.

The results

We identified 62 eligible studies. The overall FNR for the 62 articles was 4% (95% CL 3-5).There was no significant difference in the FNR in patients with high-risk endometrial cancer compared to patients with low-risk endometrial cancer. There was no difference in the FNR for whether frozen sections were used intraoperatively. The type of dye used intraoperatively (indocyanine green/blue dye) were not significantly associated with the false negative rate. Cervical injection reduced the FNR compared with alternative injection techniques. Indocyanine green reduced the FNR compared with alternative Tc-99m. Postoperative pathologic ultrastaging reduced the FNR.

Conclusions

Alternative injection techniques (other than the cervix), Tc-99m dye tracer, and the absence of postoperative pathologic ultrastaging are risk factors for a high FNR in endometrial cancer patients who undergo SLNB; therefore, we should be vigilant for missed diagnosis of metastatic lymph nodes after SLNB in such populations.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023433637.

Sentinel lymph node biopsy in endometrial cancer: When, how and in which patients

The role of nodal dissection in patients with endometrial cancer has been intensively studied in several studies. Historically, systematic pelvic and para-aortic lymphadenectomy represented the gold standard surgical treatment to assess potential nodal involvement and consequently define the appropriate stage of the tumor. Over the last years, sentinel node biopsy (SLNB) has been introduced as a more targeted alternative to lymph node dissection for lymph node staging and it has become popular among gynecologic oncologists. However, no level A evidence is still available, and several features of the SLNB technique have been matter of discussion among clinicians and a universally accepted methodology is still not currently available. This narrative review aims to summarize the body of knowledge on SLNB to offer the reader a complete picture about the evolution of this technique over the last decades.

Hysteroscopic endometrial tumor localization and sentinel lymph node mapping. An upgrade of the hysteroscopic role in endometrial cancer patients

INTRODUCTION

Given the growing interest in sentinel node mapping (SLN) biopsy in Endometrial Cancer (EC) patients, many efforts have been made to maximize the SLN bilateral detection rate. However, at present, no previous research assessed the potential correlation between primary EC location in the uterine cavity and SLN mapping. In this context, this study aims to investigate the possible role of intrauterine EC hysteroscopic localization in predicting SLN nodal placement.

MATERIALS AND METHODS

EC patients surgically treated from January 2017 to December 2021 were retrospectively analyzed. All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and SLN mapping. During hysteroscopy, the location of the neoplastic lesion was described as follows: uterine fundus (comprising the most cranial portion of the uterine cavity up to the tubal ostium including the cornual areas), corpus uteri (from the tubal ostium to the inner uterine orifice), and diffuse (when the tumor invades more than 50% of the uterine cavity).

RESULTS

Three hundred ninety patients met the inclusion criteria. The tumor pattern diffused to the whole uterine cavity was statistically associated with SLN uptake on common iliac lymph nodes (OR 2.4, 95%CI 1-5.8, p = 0.05). Patients'age is an independent factor associated with SLN failure (OR: 0.95, 95%CI 0.93-0.98, p < 0.001).

CONCLUSIONS

The study showed a statistically significant association between EC hysteroscopically spread throughout the whole uterine cavity and SLN uptake at the common iliac lymph nodes. Furthermore, patient age negatively affected the SLN detection rate.

Morbid obesity increases the failure rate of sentinel lymph node mapping for endometrial carcinoma

The goal of this study was to examine the relationship between body mass index (BMI) and the success rate of sentinel lymph node (SLN) mapping using indocyanine green and near-infrared imaging. Sentinel lymph node mapping is recommended for patients with endometrial carcinoma to reduce the rate of full lymphadenectomy and its associated morbidity such as lymphedema. A retrospective review was conducted of robotic hysterectomy procedures for patients with a coded diagnosis of endometrial cancer and a cost code for indocyanine green discharged between March, 2016 and August, 2019. Preoperative characteristics included age, BMI, and number of prior abdominal surgeries (includes cervical, adnexal, uterine or rectal procedures, caesarian section, or appendectomy). Intra and postoperative characteristics included procedure time (incision to close), estimated blood loss, the American Society of Anesthesiologists (ASA) physical status classification, uterine weight, uterine diameter, FIGO Grade, myometrial depth, and depth of myometrial invasion. SLN and non-SLN number, location, and pathology were recorded. The primary outcome was the bilateral success rate for SLN mapping. Patients with class III obesity (BMI > 40) were found to have a significantly lower success rate for SLN mapping when compared with all other BMI categories (54.1% vs. 76.1%, respectively, p < 0.01).

Endometrial Cancer. Guideline of the DGGG, DKG and DKH (S3-Level, AWMF Registry Number 032/034-OL, September 2022) - Part 2 with Recommendations on the Therapy of Precancerous Lesions and Early-stage Endometrial Cancer, Surgical Therapy, Radiotherapy and Drug-based Therapy, Follow-up Care, Recurrence and Metastases, Psycho-oncological Care, Palliative Care, Patient Education, and Rehabilitative and Physiotherapeutic Care

Summary The S3-guideline on endometrial cancer, first published in April 2018, was reviewed in its entirety between April 2020 and January 2022 and updated. The review was carried out at the request of German Cancer Aid as part of the Oncology Guidelines Program and the lead coordinators were the German Society for Gynecology and Obstetrics (DGGG), the Gynecology Oncology Working Group (AGO) of the German Cancer Society (DKG) and the German Cancer Aid (DKH). The guideline update was based on a systematic search and assessment of the literature published between 2016 and 2020. All statements, recommendations and background texts were reviewed and either confirmed or amended. New statements and recommendations were included where necessary. Aim The use of evidence-based risk-adapted therapies to treat low-risk women with endometrial cancer prevents unnecessarily radical surgery and avoids non-beneficial adjuvant radiation therapy and/or chemotherapy. For women with endometrial cancer and a high risk of recurrence, the guideline defines the optimum level of radical surgery and indicates whether chemotherapy and/or adjuvant radiation therapy is necessary. This should improve the survival rates and quality of life of these patients. The S3-guideline on endometrial cancer and the quality indicators based on the guideline aim to provide the basis for the work of certified gynecological cancer centers. Methods The guideline was first compiled in 2018 in accordance with the requirements for S3-level guidelines and was updated in 2022. The update included an adaptation of the source guidelines identified using the German Instrument for Methodological Guideline Appraisal (DELBI). The update also used evidence reviews which were created based on selected literature obtained from systematic searches in selected literature databases using the PICO process. The Clinical Guidelines Service Group was tasked with carrying out a systematic search and assessment of the literature. Their results were used by interdisciplinary working groups as a basis for developing suggestions for recommendations and statements which were then modified during structured online consensus conferences and/or additionally amended online using the DELPHI process to achieve a consensus. Recommendations Part 2 of this short version of the guideline provides recommendations on the treatment of precancerous lesions and early-stage endometrial cancer, surgical treatment, radiotherapy and drug-based therapy, follow-up, recurrence, and metastasis of endometrial cancer as well as the state of psycho-oncological care, palliative care, patient education, rehabilitative and physiotherapeutic care.

Predictive factors of sentinel lymph node failed mapping in endometrial carcinoma patients: a systematic review and meta-analysis

OBJECTIVE

In endometrial carcinoma patients, sentinel lymph node bilateral mapping fails in 20-25% of cases, with several factors affecting the likelihood of detection. However, pooled data about predictive factors of failure are lacking. The aim of this systematic review and meta-analysis was to assess the predictive factors of sentinel lymph node failed mapping in endometrial cancer patients undergoing sentinel lymph node biopsy.

METHODS

A systematic review and a meta-analysis was performed searching all studies assessing predictive factors of sentinel lymph node failed mapping in apparent uterine-confined endometrial cancer patients undergoing sentinel lymph node biopsy through the cervical injection of indocyanine green. The associations between sentinel lymph node failed mapping and predictive factors of failure were assessed, calculating the odds ratio (OR) with 95% confidence intervals.

RESULTS

Six studies with a total of 1345 patients were included. Compared with patients with sentinel lymph node bilateral successful mapping, patients with sentinel lymph node failed mapping showed: OR 1.39 (p=0.41) for body mass index >30 kg/m2; OR 1.72 (p=0.24) for menopausal status; OR 1.19 (p=0.74) for adenomyosis; OR 0.86 (p=0.55) for prior pelvic surgery; OR 2.38 (p=0.26) for prior cervical surgery; OR 0.96 (p=0.89) for prior Cesarean section; OR 1.39 (p=0.70) for lysis of adhesions during surgery before sentinel lymph node biopsy; OR 1.77 (p=0.02) for indocyanine green dose <3 mL; OR 1.28 (p=0.31) for deep myometrial invasion; OR 1.21 (p=0.42) for International Federation of Gynecology and Obstetrics (FIGO) grade 3; OR 1.89 (p=0.01) for FIGO stages III-IV; OR 1.62 (p=0.07) for non-endometrioid histotype; OR 1.29 (p=0.25) for lymph-vascular space invasion; OR 4.11 (p<0.0001) for enlarged lymph nodes; and OR 1.71 (p=0.022) for lymph node involvement.

CONCLUSION

Indocyanine green dose <3 mL, FIGO stage III-IV, enlarged lymph nodes, and lymph node involvement are predictive factors of sentinel lymph node failed mapping in endometrial cancer patients.

Lymphatic Mapping and Sentinel Node Biopsy in High-Grade Uterine Cancers

PURPOSE OF REVIEW

Sentinel lymph node (SLN) mapping has been adopted as an acceptable method of lymph node evaluation in the surgical staging for low-grade endometrial cancer. In this review, we analyze the literature on the utility of SLN mapping in high-grade endometrial cancer.

RECENT FINDINGS

SLN mapping in high-grade endometrial cancer demonstrates similar high detection rates and diagnostic accuracy as seen in low-grade endometrial cancers. However, obtaining sufficient operator experience (at least 30 cases) and following SLN mapping algorithm continues to be essential to preserving diagnostic accuracy. Although limited in retrospective study design and short-term follow-up, current studies have not demonstrated inferior survival outcomes of SLN mapping compared to traditional lymphadenectomy. SLN mapping is an acceptable and accurate method of lymph node evaluation in high-grade endometrial cancer. Future prospective studies are needed to evaluate long-term oncologic outcomes between SLN mapping and systematic lymphadenectomy in this patient population.

Efficacy and safety of indocyanine green tracer-guided lymph node dissection in minimally invasive radical gastrectomy for gastric cancer: A systematic review and meta-analysis

Background

The implementation of indocyanine green (ICG) tracer-guided lymph node dissection is still in the preliminary stages of laparoscopic surgery, and its safety and efficacy for gastric cancer remain unclear.

Methods

A systematic review was conducted in PubMed, Embase, Web of Science, the Cochrane Library, and Scopus to identify relevant subjects from inception to June 2022. The core indicators were the total number of harvested lymph nodes and the safety of the laparoscopic gastrectomy with ICG. A meta-analysis was performed to estimate the pooled weighted mean difference (WMD) and 95% confidence interval (CI).

Results

Thirteen studies and 2,027 participants were included (642 for the ICG-group and 1,385 for the non-ICG group). The mean number of lymph nodes dissected in the ICG group was significantly greater than that in the non-ICG group (WMD = 6.24, 95% CI: 4.26 to 8.22, P <0.001). However, there was no significant difference in the mean number of positive lymph nodes dissected between the ICG and the non-ICG groups (WMD = 0.18, 95% CI: −0.70 to 1.07, P = 0.879). Additionally, ICG gastrectomy did not increase the risk in terms of the operative time, estimated blood loss, and postoperative complications.

Conclusion

ICG tracer with favorable safety increases the number of harvested lymph nodes but not the number of positive lymph nodes in laparoscopic gastrectomy. More high-quality, large-sample-size randomized controlled trials are still needed to enhance this evidence.

Failure of scintigraphy lymphatic mapping in endometrial cancer. Causes and solutions

AIM

To evaluate the effect of technical problems and patient characteristics on sentinel lymph node (SLN) scintigraphic detection and mapping success in early stages of endometrial cancer (EC).

METHODS

Patients with clinical early stage EC (IA-IB) underwent SLN mapping using technetium-99m-nanocolloid,between September 2011 and February 2020. were included. There were excluded cases with technical problems, 92 patients were included for the analysis of the diagnostic performance and the relation of mapping failure (pelvic unilateral or not detected SLN) with patient (age, body mass index, previous pelvic disease or surgery) and disease characteristics (histology, grade, myometrial invasion, lymphovascular space infiltration, tumor size, and lymphatic infiltration risk).

RESULTS

The overall detection rate was 79%. Lymph node metastases were diagnosed in 7 patients. Age (p=0.01), depth of myometrial invasion ≥ 50% (p=0.04) and high risk of lymphatic infiltration (p=0.02) were positively associated with mapping failure. In multivariate analysis, age was significantly associated with mapping failure [odds ratio=1.63, 95%CI: 1.06-2.50; p=0.027].

CONCLUSIONS

Age, depth of myometrial invasion and high risk of lymphatic infiltration were the factors associated with higher mapping failure. An individualized injection technique, optimizing the methodology, could minimize the detection failures.

Sentinel node biopsy for diagnosis of lymph node involvement in endometrial cancer

BACKGROUND

Pelvic lymphadenectomy provides prognostic information for those diagnosed with endometrial (womb) cancer and provides information that may influence decisions regarding adjuvant treatment. However, studies have not shown a therapeutic benefit, and lymphadenectomy causes significant morbidity. The technique of sentinel lymph node biopsy (SLNB), allows the first draining node from a cancer to be identified and examined histologically for involvement with cancer cells. SLNB is commonly used in other cancers, including breast and vulval cancer. Different tracers, including colloid labelled with radioactive technetium-99, blue dyes, e.g. patent or methylene blue, and near infra-red fluorescent dyes, e.g. indocyanine green (ICG), have been used singly or in combination for detection of sentinel lymph nodes (SLN).

OBJECTIVES

To assess the diagnostic accuracy of sentinel lymph node biopsy (SLNB) in the identification of pelvic lymph node involvement in women with endometrial cancer, presumed to be at an early stage prior to surgery, including consideration of the detection rate.

SEARCH METHODS

We searched MEDLINE (1946 to July 2019), Embase (1974 to July 2019) and the relevant Cochrane trial registers.

SELECTION CRITERIA

We included studies that evaluated the diagnostic accuracy of tracers for SLN assessment (involving the identification of a SLN plus histological examination) against a reference standard of histological examination of removed pelvic +/- para-aortic lymph nodes following systematic pelvic +/- para-aortic lymphadenectomy (PLND/PPALND) in women with endometrial cancer, where there were sufficient data for the construction of two-by-two tables.

DATA COLLECTION AND ANALYSIS

Two review authors (a combination of HN, JM, NW, RG, and WH) independently screened titles and abstracts for relevance, classified studies for inclusion/exclusion and extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We calculated the detection rate as the arithmetic mean of the total number of SLNs detected out of the total number of women included in the included studies with the woman as the unit of analysis, used univariate meta-analytical methods to estimate pooled sensitivity estimates, and summarised the results using GRADE.

MAIN RESULTS

The search revealed 6259 unique records after removal of duplicates. After screening 232 studies in full text, we found 73 potentially includable records (for 52 studies), although we were only able to extract 2x2 table data for 33 studies, including 2237 women (46 records) for inclusion in the review, despite writing to trial authors for additional information. We found 11 studies that analysed results for blue dye alone, four studies for technetium-99m alone, 12 studies that used a combination of blue dye and technetium-99m, nine studies that used indocyanine green (ICG) and near infra-red immunofluorescence, and one study that used a combination of ICG and technetium-99m. Overall, the methodological reporting in most of the studies was poor, which resulted in a very large proportion of 'unclear risk of bias' ratings. Overall, the mean SLN detection rate was 86.9% (95% CI 82.9% to 90.8%; 2237 women; 33 studies; moderate-certainty evidence). In studies that reported bilateral detection the mean rate was 65.4% (95% CI 57.8% to 73.0%) . When considered according to which tracer was used, the SLN detection rate ranged from 77.8% (95% CI 70.0% to 85.6%) for blue dye alone (559 women; 11 studies; low-certainty evidence) to 100% for ICG and technetium-99m (32 women; 1 study; very low-certainty evidence). The rates of positive lymph nodes ranged from 5.2% to 34.4% with a mean of 20.1% (95% CI 17.7% to 22.3%). The pooled sensitivity of SLNB was 91.8% (95% CI 86.5% to 95.1%; total 2237 women, of whom 409 had SLN involvement; moderate-certainty evidence). The sensitivity for of SLNB for the different tracers were: blue dye alone 95.2% (95% CI 77.2% to 99.2%; 559 women; 11 studies; low-certainty evidence); Technetium-99m alone 90.5% (95% CI 67.7% to 97.7%; 257 women; 4 studies; low-certainty evidence); technetium-99m and blue dye 91.9% (95% CI 74.4% to 97.8%; 548 women; 12 studies; low-certainty evidence); ICG alone 92.5% (95% CI 81.8% to 97.1%; 953 women; 9 studies; moderate-certainty evidence); ICG and blue dye 90.5% (95% CI 63.2.6% to 98.1%; 215 women; 2 studies; low-certainty evidence); and ICG and technetium-99m 100% (95% CI 63% to 100%; 32 women; 1 study; very low-certainty evidence). Meta-regression analyses found that the sensitivities did not differ between the different tracers used, between studies with a majority of women with FIGO stage 1A versus 1B or above; between studies assessing the pelvic lymph node basin alone versus the pelvic and para-aortic lymph node basin; or between studies that used subserosal alone versus subserosal and cervical injection. It should be noted that a false-positive result cannot occur, as the histological examination of the SLN is unchanged by the results from any additional nodes removed at systematic lymphadenectomy.

AUTHORS' CONCLUSIONS

The diagnostic test accuracy for SLNB using either ICG alone or a combination of a dye (blue or ICG) and technetium-99m is probably good, with high sensitivity, where a SLN could be detected. Detection rates with ICG or a combination of dye (ICG or blue) and technetium-99m may be higher. The value of a SLNB approach in a treatment pathway, over adjuvant treatment decisions based on uterine factors and molecular profiling, requires examination in a high-quality intervention study.

Carbon nanoparticles combined with indocyanine green for sentinel lymph node detection in endometrial carcinoma

OBJECTIVE

To evaluate the feasibility and clinical value of the combination of carbon nanoparticles (CNPs) and indocyanine green (ICG) for identifying sentinel lymph nodes (SLNs) in endometrial cancer.

MATERIALS AND METHODS

About 153 patients with endometrial cancer were recruited from July 2015 to May 2019. All patients underwent SLN biopsy according to the SLN algorithm for surgical staging with ICG and/or CNPs. The detection rate, factors associated with the detection rate, sensitivity, and negative predictive value (NPV) of SLNs were analyzed.

RESULTS

The detection rates of SLNs with the combined method were the highest among the different methods. As calculated per hemipelvis, the sensitivity and NPV with ICG alone or with ICG plus CNPs were 100%. With CNP, tumor Grade 3 and laparoscopy were related to unsuccessful overall SLN mapping while tumor diameter greater than 2 cm and laparoscopy were statistically associated with failed bilateral mapping. With ICG, a higher body mass index was significantly associated with unsuccessful bilateral detection of SLN.

CONCLUSION

SLN assessment in endometrial cancer is feasible and safe with high sensitivity and high NPV when ICG and CNPs are combined and in low-risk patients. It is a superior option to use CNPs in laparotomy for patients with endometrial cancer.

Sentinel lymph node detection in endometrial cancer with indocyanine green: laparoscopic versus robotic approach

BACKGROUND

The aims of the present study were to assess bilateral sentinel lymph node (SLN) mapping with laparoscopic versus robotic approach, to assess variables affecting bilateral detection rates and to assess survival difference in patients with no/unilateral, compared to bilateral SLN detection.

METHODS

This is a retrospective, single-centre, observational cohort study, including patients with endometrial cancer FIGO stage IA-IVB, treated with minimally invasive primary surgery and undergoing indocyanine green (ICG) injection to detect SLN, between January 2015 and December 2019.

RESULTS

Of the 549 included patients, 286 (52.1%) and 263 (47.9%) underwent the laparoscopic and robotic approach respectively. 387 (70.5%) patients had bilateral SLN mapping, 102 (18.6%) and 60 (10.9%) had unilateral and no mapping, respectively. Patients who underwent the robotic approach were older (median 61 versus 64 years, p=0.046) and had a higher BMI (median 26.0 versus 34.8 kg/m2, p<0.001). No difference in any SLN mapping or in SLN bilateral detection was evident between the laparoscopic or robotic approach (p=0.892 and p=0.507 respectively). Patients with bilateral SLN detection in the entire cohort were younger (p<0.001) and had a better 3-year disease-free survival (DFS) compared to patients with no/unilateral SLN mapping (77.0% versus 66.3%, respectively, p=0.036). No 3-year overall survival (OS) difference was reported (p=0.491).

CONCLUSION

SLN mapping and bilateral SLN detection with ICG in endometrial cancer was not different in the laparoscopic and robotic approach, even though patients undergoing the robotic approach were older and more obese. Bilateral SLN detection was associated with improved 3-year DFS, but not with 3-year OS, compared to no and unilateral SLN detection.

Lymphadenectomy in endometrial cancer - achieving more with less?

The lymph node status of patients with endometrial cancer is known to be a crucial determinant for the prognosis of the disease. It also provides the indication for further adjuvant treatment. The staging of endometrial cancer by surgery has been a controversial issue for more than 30 years. The significant complication rate after lymphadenectomy and the development of minimally invasive surgery have led to the use of sentinel lymph node (SLN) mapping. In the present review, we present the development of surgical staging procedures in patients with endometrial cancer and summarize the recently expanding body of published literature on the subject. SLN mapping is a safe and accurate technique, especially when indocyanine green is used as a tracer. SLN mapping appears to reduce complication rates as well as costs without affecting the oncologic outcome. Large prospective studies are needed to establish the effects of SLN mapping on the outcome of disease, especially in high-risk patients with endometrial cancer. Furthermore, the need for additional systematic lymphadenectomy prior to adjuvant radio-chemotherapy in patients diagnosed with isolated lymph node metastasis during SLN biopsy must be investigated further. This might pave the way for a new surgical approach in patients with endometrial cancer.

Is It Possible to Develop a Prediction Model for Lymphovascular Space Invasion in Endometrioid Endometrial Cancer?

OBJECTIVE

The purpose of this retrospective study was to define a risk index that would serve as a surrogate marker of lymphovascular space invasion (LVSI) in women with endometrioid endometrial cancer (EC).

MATERIALS AND METHODS

Final pathology reports of 498 women who underwent surgery with curative intent for endometrioid EC between January 2008 and June 2018 were retrospectively reviewed. Logistic regression was used to investigate clinicopathologic factors associated with positive LVSI status. Independent risk factors for LVSI were used to build a risk model and "risk of LVSI index" was defined as "tumor grade×primary tumor diameter×percentage of myometrium involved." The scores used in the "risk of LVSI index" were weighted according to the odds ratios assigned for each variable. The risk of LVSI index was noted for each patient. The diagnostic performance of the model was expressed as sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio.

RESULTS

According to the "risk of LVSI index," presence of LVSI was correctly estimated in 89 of 104 LVSI-positive women at a cutoff of 161.0 (sensitivity 85.5%, specificity 79.4%, negative predictive value 95.4%, positive predictive value 52.3%, positive likelihood ratio 4.15, negative likelihood ratio 0.18). The area under curve of the receiver-operating characteristics was 0.90 (95% confidence interval, 0.87-0.93) at this cutoff.

CONCLUSIONS

It seems possible to predict the presence of LVSI in women with endometrioid EC when the "risk of LVSI index" is calculated. However, external validation of this model is warranted.

Differential Impact of Systemic Lymphadenectomy Upon the Survival of Patients with Type I vs Type II Endometrial Cancer: A Retrospective Observational Cohort Study

PURPOSE

To determine whether systemic lymphadenectomy exerts a similar effect on the survival of patients with either type I or type II endometrial cancer (EC).

PATIENTS AND METHODS

In this retrospective study, 682 eligible patients diagnosed with EC were typed according to the pathological reports. The thoroughness of lymphadenectomy was evaluated by the lymph node number of which the cut-off value was determined by the receiver operator characteristic (ROC) curve and Youden index. The impact of thoroughness on the survival of both types was analyzed, respectively, by Kaplan Meier (K-M) method and further evaluated in subgroups with and without lymphatic metastasis. Independent prognostic factors of survival were selected by proportional hazard regression (Cox) model.

RESULTS

The cut-off level of lymph node number was 20. The differential impact of the lymph node number removed on survival was noted when patients with different types were analyzed separately. Among type II EC, those with >20 lymph nodes removed presented better overall survival (OS) than those with ≤20 (p=0.002). The number of lymph nodes removed >20 was proved as an independent factor for improved OS in type II EC (HR=0.329,95% CI: 0.123-0.881, p=0.0027). In the subgroup of type II with >20 lymph nodes resected, similar 5-year OS rates were observed in those with or without identified positive node (90.9% vs 92.9%, p=0.965). Type I EC seemed unbeneficial from such a procedure.

CONCLUSION

Systemic lymphadenectomy could enhance the OS of type II EC other than type I.

Sentinel Lymph Nodes in Endometrial Cancer Update 2018

There are no established data about lymphadenectomy during treatment of endometrial cancers (ECs) and to what extent lymphadenectomy should be performed. In addition, retroperitoneal lymphadenectomy increases the intraoperative and postoperative complications. Sentinel lymph node (SLN) mapping has the lowest costs and highest quality-adjusted survival. SLN is the most cost-effective strategy in the management of low-risk ECs. Women staged with SLN mapping were more likely to receive adjuvant treatment compared with women staged with systemic lymphadenectomy. This review article designed to evaluate the diagnostic accuracy and the methods of SLN detection in ECs.

Robotic sentinel node mapping in clinical stage 1 endometrial cancer using methylene blue dyes using the robotic platform

PURPOSE

Endometrial cancer is a surgically staged cancer. We examined our preliminary experience with sentinel lymph node (SLN) mapping in early stage endometrial cancer using methylene blue dyes.

METHOD

Retrospective review of all clinically stage 1 endometrial cancer staged surgically using the robotic platform. Logistic regression models were built to predict nodal metastasis taking into account age, grade, histology, depth of myometrial invasion, cervical involvement, and use of SLN mapping.

RESULTS

Four hundred sixty-nine patients were reviewed. Sixty patients had SLN mapping (13%). Four hundred nine patients underwent standard lymphadenectomy with five documented nodal metastasis (1.2%). Five nodal metastasis (8.3%) were seen in the SLN patients. In the logistic model, the application of SLN mapping was significantly associated with diagnosed nodal metastasis (OR 7.74; 95% CI, 2.04-29.3; P = .003) together with nonendometroid histology (OR 5.05; 95% CI, 1.27-20.12; P = .022).

CONCLUSION

SLN mapping protocol using methylene blue significantly identifies more nodal metastasis than standard lymphadenectomy.

Adipose-only sentinel lymph nodes: a finding during the adaptation of a sentinel lymph node mapping algorithm with indocyanine green in women with endometrial cancer

OBJECTIVE

To identify factors that affect successful adaptation of sentinel lymph node mapping and those that lead to unintended adipose-only sentinel lymph node identification.

METHODS

Surgical and pathological data were prospectively collected on patients with endometrial cancer who underwent sentinel lymph node mapping with indocyanine green with or without pelvic and/or para-aortic lymph node dissection between November 2013 and April 2017. All mapping cases were performed with the robotic system. Adipose-only specimens were defined as a sentinel lymph node without a pathologically identified lymph node after ultrastaging.

RESULTS

A total of 202 patients were included: 83% had endometrioid pathology, 12% serous, 3% carcinosarcoma, and 2% clear cell, with mixed pathology noted in 2%. The bilateral sentinel lymph node detection rate was 66%, and the rate of mapping at least a unilateral sentinel lymph node was 86%. Neither the bilateral nor the unilateral sentinel lymph node mapping rate changed with increased surgeon experience. The rate of adipose-only sentinel lymph node identification was more frequent when comparing the first 10 cases (37%), cases 11 - 30 (28%), and > 30 cases (9%) (P = 0.006). Body mass index > 30 kg/m2, uterine fibroids, The International Federation of Gynecology and Obstetrics (FIGO) grade, and histology were not found to have a statistically significant impact on either sentinel lymph node identification or adipose-only sentinel lymph node identification. Adipose-only sentinel lymph nodes were more likely with increased time from cervical injection to identification of the sentinel lymph node in the right hemipelvis. The median range was 28 min (14-73) for true sentinel lymph node identification vs 33 min (23-74) for adipose-only sentinel lymph node identification (P = 0.02).

CONCLUSION

Patient and surgeon factors did not impact the identification of sentinel lymph nodes over time. Adipose-only sentinel lymph nodes were more frequently identified in the initial cases and represent a potential complication to adapting sentinel lymph node biopsy without lymphadenectomy. The increase in adipose-only sentinel lymph node identification that was associated with time from cervical injection may represent delayed or disrupted uptake of indocyanine green.

Comparison Study of Laparoscopic Sentinel Lymph Node Mapping in Endometrial Carcinoma Using Carbon Nanoparticles and Lymphatic Pathway Verification

STUDY OBJECTIVE

To evaluate the detection rate and accuracy of sentinel lymph node (SLN) mapping using cervical and fundal injections of carbon nanoparticles (CNPs) in laparoscopic surgery of endometrioid endometrial cancer (EC) and to identify uterine lymphatic drainage pathways validated by mapping.

DESIGN

A prospective consecutive study (Canadian Task Force classification II-2).

SETTING

An academic research center.

PATIENTS

Consecutive patients with a pathologic diagnosis of early-stage EC scheduled for primary laparoscopic-assisted staging surgery (laparoscopic hysterectomy, bilateral salpingo-oophorectomy, or comprehensive lymphadenectomy).

INTERVENTIONS

Enrolled patients underwent laparoscopic SLN mapping with a 50-mg CNP tracer injection. Fifty patients received fundal subserosal injections at 4 sites (the fundal group), whereas 65 patients received cervical submucosal injections at 2 sites (the cervical group). After SLN mapping, all patients underwent laparoscopic staging surgery.

MEASUREMENTS AND MAIN RESULTS

No allergic reactions to CNPs were observed in either group. The overall SLN detection rates were 100% and 92% in the cervical and fundal groups, and the bilateral SLN detection rates were 97% and 68% (p < .001), respectively. A total of 12 metastatic SLNs were accurately detected in 5 patients. The sensitivity of metastatic lymph node detection was 100% in the cervical group, which is higher than that in the fundal group (80%). The false-negative rates were 0% and 20%, respectively, in the cervical and fundal groups. Furthermore, we verified 3 uterine lymphatic pathways using the 2 injection methods. The upper paracervical pathway was the most common drainage pathway in both groups (91.4% in the cervical group vs 80.24% in the fundal group), whereas the infundibulopelvic pathway was observed only in the fundal group (15.11%).

CONCLUSION

SLN mapping by CNPs in laparoscopic surgery for EC is a safe and effective alternative, with a higher detection rate and better accuracy with cervical injections than fundal injections. The upper paracervical pathway was the most common lymphatic pathway, whereas the infundibulopelvic pathway was only displayed in fundal injections.