Sentinel lymph node procedure in endometrial cancer: A systematic review and proposal for standardization of future research

Evaluation of One Step Nucleic Acid Amplification for detection of lymph node metastases compared to histopathological ultrastaging in women with endometrial cancer: a protocol for a diagnostic accuracy study

BACKGROUND

This is a multicentre, European, prospective trial evaluating the diagnostic accuracy of One Step Nucleic Acid Amplification (OSNA) compared to sentinel lymph nodes histopathological ultrastaging in endometrial cancer patients.

METHODS

Centres with expertise in sentinel lymph node mapping in endometrial cancer patients in Europe will be invited to participate in the study. Participating units will be trained on the correct usage of the OSNA RD-210 analyser and nucleic acid amplification reagent kit LYNOAMP CK19 E for rapid detection of metastatic nodal involvement, based on the cytokeratin 19 (CK19) mRNA detection. Endometrial cancer patients ≥ 18 years listed for surgical treatment with sentinel lymph node mapping, with no history of other types of cancer and who provide a valid written consent will be considered potentially eligible for the study. However, they will only be enrolled if a successful sentinel lymph node mapping is retrieved. Each node will be processed according to the study protocol and assessed by both OSNA and ultrastaging.

DISCUSSION

The accuracy of OSNA (index test) will be assessed against sentinel lymph node histopathological ultrastaging (reference test). This European study has the potential to be the largest study on the use of OSNA in endometrial cancer to date. OSNA could represent a modern diagnostic alternative to sentinel lymph node ultrastaging with the added benefits of standardisation and fast results.

TRIAL REGISTRATION

The study was registered in the German Clinical Trial Register - Nr. DRKS00021520, registration date 25th of May 2020, URL of the trial registry record: https://drks.de/search/en/trial/DRKS00021520 .

[Nuclear medicine procedure guideline for sentinel lymph node localization]

The authors present a procedure guideline for scintigraphic detection of sentinel lymph nodes in malignant melanoma, in breast cancer, in penile and vulva tumors, in head and neck cancer, and in prostate carcinoma. Important goals of sentinel lymph node scintigraphy comprise reduction of the extent of surgery, lower postoperative morbidity and optimization of histopathological examination focussing on relevant lymph nodes. Sentinel lymph node scintigraphy itself does not diagnose tumorous lymph node involvement and is not indicated when lymph node or distant metastases have been definitely diagnosed before sentinel lymph node scintigraphy. Procedures are compiled with the aim to reliably localise sentinel lymph nodes with a high detection rate typically in early tumour stages. New aspects in this guideline are new radiopharmaceuticals such as tilmanocept and Tc-99m-PSMA and SPECT/CT allowing an easier anatomical orientation. Initial dynamic lymphoscintigraphy in breast cancer is of little significance nowadays. Radiation exposure is low so that pregnancy is not a contraindication for sentinel lymph node scintigraphy. A one-day protocol should preferentially be used. Even with high volumes of scintigraphic sentinel lymph node procedures surgeons, theatre staff and pathologists receive a radiation exposure < 1 mSv/year so that they do not require occupational radiation surveillance. Aspects of quality control were included (scintigraphy, quality control of gamma probe, 6 h SLN course for surgeons, certified breast centers, medical surveillance center).

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.

Additional Value of FDG-PET/MRI Complementary to Sentinel Lymphonodectomy for Minimal Invasive Lymph Node Staging in Patients with Endometrial Cancer: A Prospective Study

BACKGROUND

Lymph node metastases (LNM) are rare in early-stage endometrial cancer, but a diagnostic systematic lymphadenectomy (LNE) is often performed to achieve reliable N-staging. Therefore, this prospective study aimed to evaluate the benefit of [18F]-Fluorodeoxyglucose (FDG) PET/MRI complementary to SPECT/CT guided sentinel lymphonodectomy (SLNE) for a less invasive N-staging Methods: 79 patients underwent a whole-body FDG-PET/MRI, SLN mapping with 99mTc-Nanocolloid SPECT/CT and indocyanine green (ICG) fluoroscopy followed by LNE which served as ground truth.

RESULTS

FDG-PET/MRI was highly specific in N-staging (97.2%) but revealed limited sensitivity (66.7%) due to missed micrometastases. In contrast, bilateral SLN mapping failed more often in patients with macrometastases. The combination of SLN mapping and FDG-PET/MRI increased the sensitivity from 66.7% to 77.8%. Additional SLN labeling with dye (ICG) revealed a complete SLN mapping in 80% (8/10) of patients with failed or incomplete SLN detection in SPECT/CT, reducing the need for diagnostic systematic LNE up to 87%. FDG-PET/MRI detected para-aortic LNM in three out of four cases and a liver metastasis.

CONCLUSIONS

The combination of FDG-PET/MRI and SLNE can reduce the need for diagnostic systematic LNE by up to 87%. PET/MRI complements the SLN technique particularly in the detection of para-aortic LNM and occasional distant metastases.

Recent management of endometrial cancer: a narrative review of the literature

Endometrial cancer is a common female gynecological neoplasia and its incidence rate has increased in the past years. Due to its predominant symptoms, most women will present uterine bleeding. It is usually diagnosed at an early stage and surgery has an important role in the treatment plan. The prognosis and quality of life of these patients can be quite favorable, if proper treatment is offered by surgeons. Traditionally, more invasive approaches and procedures were offered to these patients, but recent data suggest that more conservative and minimal invasive choices can be adopted in the treatment algorithm. Minimal invasive surgery, such as laparoscopy and robotic surgery, should be considered as an acceptable alternative, compared to laparotomy with less comorbidities and similar oncological and survival outcomes. Furthermore, sentinel lymph node biopsy has emerged in the surgical staging of endometrial cancer, in order to replace comprehensive lymphadenectomy. It is associated with less intra- and postoperative complications, while preliminary data show no difference in survival rates. However, sentinel lymph node biopsy should be offered within a strict algorithm, to avoid residual metastatic disease. The aim of this review is to analyze all the available data for the application of minimal invasive surgery in early endometrial cancer and especially the role of sentinel lymph node biopsy.

Robotic para-aortic sentinel lymph node mapping in endometrial, cervical, and ovarian cancer

The concept of pelvic sentinel lymph node mapping has been well-investigated in endometrial and cervical cancer. A variety of tracers have been used including blue dye, technetium-99-m (Tc-99 m), and fluorescent tracer indocyanine green. Pelvic sentinel lymph node mapping has shown its safety, efficacy, and diagnostic accuracy, with high sensitivity and negative predictive value of more than 90%, in retrospective cohort studies as well as in prospective trials for robotic surgery. The concept of pelvic sentinel lymph node biopsy has been incorporated in several international guidelines in early-stage endometrial cancer and a subgroup of early-stage cervical cancer, although survival data are still needed to confirm its standard use. The application of para-aortic sentinel lymph node mapping is still in a development phase, but its detection rate and diagnostic accuracy seem to be promising in initial studies. Here, an overview is given of the recent developments in the different methodologies used for identifying para-aortic sentinel lymph nodes in endometrial, cervical, and ovarian cancer.

AORTIC SENTINEL NODE DETECTION IN ENDOMETRIAL CANCER: 6 YEAR PROSPECTIVE STUDY

OBJECTIVE

The aim of this study was to describe our final results using dual cervical and fundal indocyanine green injection for the detection of sentinel lymph nodes (SLNs) in endometrial cancer along parametrial and infundibular drainage pathways.

METHODS

We conducted a prospective observational study between 26 June 2014 and 31 December 2020 enrolling 332 patients that underwent laparoscopic surgery for endometrial cancer at our hospital. In all cases, we performed SLN biopsy with dual cervical and fundal indocyanine green injection identifying pelvic and aortic SLNs. All SLNs were processed with an ultrastaging technique. A total of 172 patients also underwent total pelvic and para-aortic lymphadenectomy.

RESULTS

The detection rates were as follows: 94.0% overall for SLNs; 91.3% overall for pelvic SLNs; 70.5% for bilateral SLNs; 68.1% for para-aortic SLNs, and 3.0% for isolated paraaortic SLNs. We found lymph node involvement in 56 (16.9%) cases, macrometastasis in 22, micrometastasis in 12 and isolated tumor cells in 22. Fourteen patients had isolated aortic nodal involvement, representing 25% of the positive cases. There was one false negative (SLN biopsy negative but lymphadenectomy positive). Applying the SLN algorithm, the sensitivity of the dual injection technique for SLN detection was 98.3% (95% CI 91-99.7), specificity 100% (95% CI 98.5-100), negative predictive value 99.6% (95% CI 97.8-99.9), and positive predictive value 100% (95% CI 93.8-100). Overall survival at 60 months was 91.35%, with no differences between patients with negative nodes, isolated tumor cells and treated nodal micrometastasis.

CONCLUSIONS

Dual sentinel node injection is a feasible technique that achieves adequate detection rates. Additionally, this technique allows a high rate of aortic detection, identifying a non-negligible percentage of isolated aortic metastases. Aortic metastases in endometrial cancer account for as many as a quarter of the positive cases and should be considered, especially in high-risk patients.

Uterine Neoplasms, Version 1.2023, NCCN Clinical Practice Guidelines in Oncology

Adenocarcinoma of the endometrium (also known as endometrial cancer, or more broadly as uterine cancer or carcinoma of the uterine corpus) is the most common malignancy of the female genital tract in the United States. It is estimated that 65,950 new uterine cancer cases will have occurred in 2022, with 12,550 deaths resulting from the disease. Endometrial carcinoma includes pure endometrioid cancer and carcinomas with high-risk endometrial histology (including uterine serous carcinoma, clear cell carcinoma, carcinosarcoma [also known as malignant mixed Müllerian tumor], and undifferentiated/dedifferentiated carcinoma). Stromal or mesenchymal sarcomas are uncommon subtypes accounting for approximately 3% of all uterine cancers. This selection from the NCCN Guidelines for Uterine Neoplasms focuses on the diagnosis, staging, and management of pure endometrioid carcinoma. The complete version of the NCCN Guidelines for Uterine Neoplasms is available online at NCCN.org.

Personalized Sentinel Node Mapping in Endometrial Cancer by the Indocyanine Green Implementation as Single Tracer: A Case Control Study

The main objective was to analyze the rate of bilateral sentinel lymph node (SLN) detection in endometrial cancer using indocyanine green (ICG) as a unique tracer compared to Technetium99 + ICG. As secondary objectives, we analyzed the drainage pattern and factors that might affect the oncological outcomes. A case-control ambispective study was carried out on consecutive patients at our center. Data on the SLN biopsy with ICG collected prospectively were compared to retrospective data on the use of a double-tracer technique including Technetium99 + ICG. In total, 194 patients were enrolled and assigned to both groups, in which the group with both tracers (controls) included 107 (54.9%) patients and the ICG-alone group (cases) included 87 (45.1%) patients. The rate of bilateral drainage was significantly higher in the ICG group (98.9% vs. 89.7%; p = 0.013). The median number of nodes retrieved was higher in the control group (three vs. two nodes; p < 0.01). We did not find survival differences associated with the tracer used (p = 0.85). We showed significant differences in terms of disease-free survival regarding the SLN location (p < 0.01), and obturator fossa retrieved nodes showed better prognosis compared to external iliac. The use of ICG as a single tracer for SLN detection in endometrial cancer patients seemed to obtain higher rates of bilateral detection with similar oncological outcomes.

The Role of Sentinel Lymph Node Mapping in High-grade Endometrial Cancer

OPINION STATEMENT

Total hysterectomy with lymph node assessment is the current standard-of-care for surgical staging in apparent early-stage endometrial cancer. Compared to the traditional complete pelvic lymphadenectomy with or without para-aortic lymphadenectomy, sentinel lymph node (SLN) mapping results in fewer surgical complications, decreased operative time, and lower rates of chronic lymphedema. The technique is endorsed by the National Comprehensive Cancer Network and the Society of Gynecologic Oncology guidelines, and over the past two decades the majority of gynecologic oncologists worldwide have adopted SLN mapping into their practice. However, as the results of the initial SLN studies were mostly based on low-grade tumors, adoption of the technique in high-grade tumors has been slower and more controversial. In this review, we discuss the most recent studies evaluating the SLN mapping in high-grade endometrial cancers. The results of these studies suggest that the SLN detection rate is acceptably high and the negative predictive value is sufficiently low to support the use of SLN mapping in high-grade endometrial tumors to replace complete lymphadenectomy. Validity of SLN mapping techniques does, however, require following a standard algorithm, and success depends also on surgeon expertise. Moreover, the impact of SLN mapping on overall survival in high-grade tumors requires future prospective randomized studies. Finally, a transition toward near-universal SLN mapping techniques for endometrial cancers could significantly impact on the adequacy of gynecologic oncology fellows' surgical training and competency in lymphadenectomy.

Lymph Node Mapping for Tumor Micrometastasis

Lymph node mapping for tumor micrometastasis is of great significance for the prevention, prognosis, and treatment of cancer. Currently, the traditional clinical detection methods (computed tomography, magnetic resonance imaging, or positron emission tomography/computed tomography) in clinical lymph node mapping still have some inherent disadvantages, which have prompted the development of various fluorescent probes for lymph node mapping. However, the conventional fluorescent probes such as indocyanine green or methylene blue in lymph node mapping are still accompanied by several problems such as impaired surgical field vision due to dye staining or less accumulation and shorter retention time in the lymph node. In a recent achievement, newly designed nanoparticles are prepared with novel properties that could be attractive for lymph node mapping. In this review, we will provide details on the progress of various nanoparticles for lymph node mapping and emphasize other multivariant properties in different nanoparticles, including strong tumor-targeting affinity and specificity, self-luminescence, and even with the function to kill metastatic cancer cells.

Sentinel Lymph Node Biopsy in Endometrial Cancer: Dual Injection, Dual Tracer—A Multidisciplinary Exhaustive Approach to Nodal Staging

Simple Summary

Since clinical guidelines accepted the utilization of sentinel lymph node (SLN) in apparent uterine-confined endometrial cancer (EC), many centers have already used it as a standard staging surgery. The most widely accepted tracer is ICG alone, but several studies comment on the importance of surgeon experience in order not to lose sensitivity in the first 30-40 cases. This is a prospective, observational single-center trial designed to improve SLN detection rate specially during learning curve. The application of dual tracer (indocyanine green (ICG) and Technetium99 (Tc99) injected separately) helps us to reach a very good overall and bilateral SLN pelvic detection rate in early-stage endometrial cancer patients. Dual injection (cervical and fundal) improves para-aortic SLN detection rate.

Abstract

Introduction: Sentinel lymph node (SLN) has recently been introduced as a standard staging technique in endometrial cancer (EC). There are some issues regarding team experience and para-aortic detection. Objective: to report the accuracy of SLN detection in EC with a dual tracer (ICG and Tc99) and dual injection site (cervix and fundus) during the learning curve. Methods: A prospective, observational single-center trial including 48 patients diagnosed with early-stage EC. Dual intracervical tracer (Tc99 and ICG) was injected at different times. High-risk patients had a second fundus injection with both tracers. Results: the detection rates were as follows: 100% (48/48) overall for SLNs; 98% (47/48) overall for pelvic SLNs; 89.5% (43/48) for bilateral SLNs; and 2% (1/48) for isolated para-aortic SLNs. In high-risk patients, the para-aortic overall DR was 66.7% (22/33); 60.7% (17/28) with ICG and 51.5% (17/33) with Tc99 (p = 0.048)). Overall rate of lymph node involvement was 14.6% (7/48). Macroscopic pelvic metastasis was found in four patients (8.3%) and microscopic in one case (2%). No metastasis was found in any para-aortic SLNs. Half of the patients with positive pelvic SLNs had positive para-aortic nodes. In high-risk patients, when para-aortic SLNs mapped failed, 36.4% (4/11) had positive nodes in para-aortic lymphadenectomy. The sensitivity and negative predictive value (NPV) of SLN pelvic detection was 100%. Conclusions: Multidisciplinary exhaustive approach gives a suitable accuracy of SLN during learning curve. Dual injection (cervical and fundal) with dual tracer (ICG and Tc99) offers good overall detection rates and increases para-aortic SLN detection.

Sentinel Lymph Node Sampling in Robot-Assisted Staging of Endometrial Cancer

OBJECTIVE

Sentinel lymph node (SLN) sampling in endometrial cancer staging has become an acceptable standard. Indocyanine green dye injected into the cervix and detected by near-infrared light is technically simple and sensitive. We aimed to evaluate SLN sampling in robot-assisted surgical staging of endometrial cancer at a university-affiliated teaching hospital.

METHODS

A retrospective chart review, from January 2016 to December 2017, of patients who underwent robot-assisted surgical staging with cervical injection of indocyanine green dye detected by near-infrared light. The map rate, sensitivity, false negatives, and negative predictive value were calculated.

RESULTS

A total of 105 charts were reviewed; 79 patients met inclusion criteria. The mean age was 65 (range 38-93) and the mean body mass index was 33.3 (range 16-49). Most patients (72.2%) had stage I disease and grade 1 or 2 histology (77.1%). Eight (10.1%) patients had lymph node metastasis. Seventy-two (91.1%) patients had positive mapping to at least 1 SLN. Sixty-two (78.5%) patients had bilateral mapping. Forty-four patients had concurrent pelvic ± para-aortic lymph node dissection and were included in the sensitivity analysis. Five of 44 cases had LN metastasis. The sensitivity was 80%, and the negative predictive value of SLN sampling was 97.5%.

CONCLUSIONS

SLN mapping and sampling at a university-affiliated teaching hospital have comparable map rate, sensitivity, and negative predictive value as demonstrated in multiple trials. The technique has the potential to standardize endometrial cancer staging across different practice settings.

Sentinel lymph node biopsy in high-grade endometrial cancer: a systematic review and meta-analysis of performance characteristics

OBJECTIVE

A sentinel lymph node biopsy is widely accepted as the standard of care for surgical staging in low-grade endometrial cancer, but its value in high-grade endometrial cancer remains controversial. The aim of this systematic review and meta-analysis was to evaluate the performance characteristics of sentinel lymph node biopsy in patients with endometrial cancer with high-grade histology (registered in the International Prospective Register of Systematic Reviews with identifying number CRD42020160280).

DATA SOURCES

We systematically searched the MEDLINE, Epub Ahead of Print, MEDLINE In-Process & Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Embase databases all through the OvidSP platform. The search was performed between January 1, 2000, and January 26, 2021. ClinicalTrials.gov was searched to identify ongoing registered clinical trials.

STUDY ELIGIBILITY CRITERIA

We included prospective cohort studies in which sentinel lymph node biopsy were evaluated in clinical stage I patients with high-grade endometrial cancer (grade 3 endometrioid, serous, clear cell, carcinosarcoma, mixed, undifferentiated or dedifferentiated, and high-grade not otherwise specified) with a cervical injection of indocyanine green for sentinel lymph node detection and at least a bilateral pelvic lymphadenectomy as a reference standard. If the data were not reported specifically for patients with high-grade histology, the authors were contacted for aggregate data.

METHODS

We pooled the detection rates and measures of diagnostic accuracy using a generalized linear mixed-effects model with a logit and assessed the risk of bias using the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

RESULTS

We identified 16 eligible studies of which the authors for 9 of the studies provided data on 429 patients with high-grade endometrial cancer specifically. The study-level median age was 66 years (range, 44-82.5 years) and the study-level median body mass index was 28.6 kg/m² (range, 19.4-43.7 kg/m²). The pooled detection rates were 91% per patient (95% confidence interval, 85%-95%; I²=59%) and 64% bilaterally (95% confidence interval, 53%-73%; I²=69%). The overall node positivity rate was 26% (95% confidence interval, 19%-34%; I²=44%). Of the 87 patients with positive node results, a sentinel lymph node biopsy correctly identified 80, yielding a pooled sensitivity of 92% per patient (95% confidence interval, 84%-96%; I²=0%), a false negative rate of 8% (95% confidence interval, 4%-16%; I²=0%), and a negative predictive value of 97% (95% confidence interval, 95%-99%; I²=0%).

CONCLUSION

Sentinel lymph node biopsy accurately detect lymph node metastases in patients with high-grade endometrial cancer with a false negative rate comparable with that observed in low-grade endometrial cancer, melanoma, vulvar cancer, and breast cancer. These findings suggest that sentinel lymph node biopsy can replace complete lymphadenectomies as the standard of care for surgical staging in patients with high-grade endometrial cancer.

One-Step Nucleic Acid Amplification (OSNA) of Sentinel Lymph Node in Early-Stage Endometrial Cancer: Spanish Multicenter Study (ENDO-OSNA)

The objective of this study was to evaluate the efficacy of one-step nucleic acid amplification (OSNA) for the detection of sentinel lymph node (SLN) metastasis compared to standard pathological ultrastaging in patients with early-stage endometrial cancer (EC). A total of 526 SLNs from 191 patients with EC were included in the study, and 379 SLNs (147 patients) were evaluated by both methods, OSNA and standard pathological ultrastaging. The central 1 mm portion of each lymph node was subjected to semi-serial sectioning at 200 μm intervals and examined by hematoxylin-eosin and immunohistochemistry with CK19; the remaining tissue was analyzed by OSNA for CK19 mRNA. The OSNA assay detected metastases in 19.7% of patients (14.9% micrometastasis and 4.8% macrometastasis), whereas pathological ultrastaging detected metastasis in 8.8% of patients (3.4% micrometastasis and 5.4% macrometastasis). Using the established cut-off value for detecting SLN metastasis by OSNA in EC (250 copies/μL), the sensitivity of the OSNA assay was 92%, specificity was 82%, diagnostic accuracy was 83%, and the negative predictive value was 99%. Discordant results between both methods were recorded in 20 patients (13.6%). OSNA resulted in an upstaging in 12 patients (8.2%). OSNA could aid in the identification of patients requiring adjuvant treatment at the time of diagnosis.

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.

Update on Sentinel Lymph Node Biopsy in Surgical Staging of Endometrial Carcinoma

Sentinel lymph node (SLN) biopsy has emerged as an alternative staging approach in women with assumed early-stage endometrial carcinoma. Through image-guided surgery and pathologic ultrastaging, the SLN approach is introducing “precision medicine” to the surgical management of gynecologic cancers, providing a comprehensive evaluation of high-yield lymph nodes. This approach improves the surgeons’ ability to detect small-volume metastatic disease while reducing intraoperative and postoperative morbidity associated with lymphadenectomy. Although the majority of clinicians in Europe and the USA have recognized the value of SLN biopsy in endometrial carcinoma and introduced this as part of clinical practice, there is ongoing debate regarding its role in very low-risk patients as well as in patients at high risk of nodal metastasis. The significance of low-volume metastasis is not fully understood, and there is no consensus in regard to how the presence of isolated tumor cells should guide adjuvant therapy. Standardized protocols for histopathologic evaluation of SLNs are lacking. In this review article we aim to provide a framework for the introduction of SLN biopsy in endometrial cancer, give an updated overview of the existing literature, as well as discuss potential controversies and unanswered questions regarding this approach and future directions.

Major clinical research advances in gynecologic cancer in 2020

In 2020 series, we summarized the major clinical research advances in gynecologic oncology with providing representative figures of the most influential study for 1 of each 3 gynecologic cancers: cervix, ovary, and uterine corpus. Review for cervical cancer covered targeted agents and immune checkpoint inhibitors, adjuvant radiation therapy or concurrent/sequential chemoradiation therapy after radical hysterectomy in early cervical cancer, radical surgery in early cervical cancer; and prevention and screening. Ovarian cancer research included studies of various combinations of poly (ADP-ribose) polymerase inhibitors with chemotherapy, immune checkpoint inhibitors, and/or vascular endothelial growth factor inhibitors according to the clinical setting. For uterine corpus cancer, molecular classification upon which the decision of adjuvant treatments might be based, World Health Organization recommendation of 2-tier grading system (low grade vs. high grade), sentinel lymph node assessment and ovarian preservation in clinically early-stage endometrial cancer were reviewed. Molecular targeted agents including immune checkpoint inhibitors which showed promising anti-tumor activities in advanced/recurrent endometrial cancer were also included in this review.

Sentinel Lymph Node Mapping in Endometrial Cancer: A Comprehensive Review

Endometrial cancer (EC) is known as a common gynecological malignancy. The incidence rate is on the increase annually. Lymph node status plays a crucial role in evaluating the prognosis and selecting adjuvant therapy. Currently, the patients with high-risk (not comply with any of the following: (1) well-differentiated or moderately differentiated, pathological grade G1 or G2; (2) myometrial invasion< 1/2; (3) tumor diameter < 2 cm are commonly recommended for a systematic lymphadenectomy (LAD). However, conventional LAD shows high complication incidence and uncertain survival benefits. Sentinel lymph node (SLN) refers to the first lymph node that is passed by the lymphatic metastasis of the primary malignant tumor through the regional lymphatic drainage pathway and can indicate the involvement of lymph nodes across the drainage area. Mounting evidence has demonstrated a high detection rate (DR), sensitivity, and negative predictive value (NPV) in patients with early-stage lower risk EC using sentinel lymph node mapping (SLNM) with pathologic ultra-staging. Meanwhile, SLNM did not compromise the patient’s progression-free survival (PFS) and overall survival (OS) with low operative complications. However, the application of SLNM in early-stage high-risk EC patients remains controversial. As revealed by the recent studies, SLNM may also be feasible, effective, and safe in high-risk patients. This review aims at making a systematic description of the progress made in the application of SLNM in the treatment of EC and the relevant controversies, including the application of SLNM in high-risk patients.

The Advantage of Pinpoint Camera System With Indocyanine Green for Sentinel Lymph Node Micrometastasis Detection in Low Risk Endometrial Cancer

BACKGROUND/AIM

This report outlines our experience in the management of 10 cases of low-risk endometrial cancer with Indocyanine Green for sentinel lymph node (SLN) mapping using the Pinpoint 30-degree 4K S1 SPY real-time camera system (Stryker). This system offers simultaneous, real-time, high-definition white light and fluorescence imaging through a single laparoscope, without the need to change camera filters.

PATIENTS AND METHODS

In our retrospective case series we included all endometrioid endometrial cancers of grade G1 and pre-operative radiological staging FIGO 1A reported on magnetic resonance imaging (MRI) that were treated laparoscopically from October 2019 to April 2020.

RESULTS

Bilateral sentinel lymph node excision was achieved in 9 out of 10 cases. In one patient, one sentinel lymph node featuring a micrometastasis of <2 mm was identified.

CONCLUSION

A specialist minimal access team can safely and reliably reproduce this technique for sentinel lymph node excision.

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.

Maximizing sentinel node detection in endometrial cancer with dual cervical and transcervical fundal indocyanine green injection: 5-year single-center prospective study

OBJECTIVE

The aim of this study was to describe our latest results using dual cervical and fundal indocyanine green injection for detection of sentinel lymph node (SLN) in endometrial cancer.

METHODS

A prospective observational study was conducted between 26 June 2014 and 31 December 2019 with 278 patients that underwent laparoscopic surgery for endometrial cancer at our institution. In all cases, we performed SLN biopsy with dual cervical and fundal indocyanine green injection. All SLNs were processed with an ultrastaging technique. A total of 128 patients also underwent total pelvic and paraaortic lymphadenectomy.

RESULTS

The detection rates were as follows: 93.5 % (260/278) overall for SLNs; 90.7 % (252/278) overall for pelvic SLNs; 68.0 % (189/278) for bilateral SLNs; 66.9 % (186/278) for paraaortic SLNs, and 2.9 % (8/278) for isolated paraaortic SLNs. We found macroscopic lymph node metastasis in 26 patients (10.0 %) and microdisease in lymph nodes in another 48 patients, raising the overall rate of lymph node involvement to 16.2 %. There was one false negative (negative SLN biopsy but positive lymphadenectomy). Applying the SLN algorithm, the sensitivity of detection was 97.9 % (95 % CI 89.1-99.6), specificity 100 % (95 % CI 98.2-100), negative predictive value 99.5 % (95 % CI 97.4-99.9), and positive predictive value 100 % (95 % CI 92.4-100).

CONCLUSIONS

Dual sentinel node injection is a feasible technique that achieves adequate detection rates. Additionally, this technique allows a high rate of aortic detection, identifying a non-negligible percentage of isolated aortic metastases. Aortic metastases in endometrial cancer are possible and we should not give up actively looking for them.

Paucity of data evaluating patient centred outcomes following sentinel lymph node dissection in endometrial cancer: A systematic review

•

SLND has potentially favourable patient-centred outcomes over systematic LND.

•

High-quality evidence comparing SLND with other methods of staging is lacking.

•

SLND was associated with shorter operating times and lower estimated blood loss.

•

Intraoperative and postoperative complications were not conclusively different.

Sentinel lymph node dissection (SLND) is presently used by the majority of gynaecologic oncologists for surgical staging of endometrial cancer. SLND assimilated into routine surgical practice because it increases precision of surgical staging and may reduce morbidity compared to a full, systematic LND. Previous research focussed on the accuracy of SLND. Patient centred outcomes have never been conclusively demonstrated. The objective of this systematic review was to evaluate patient centred outcomes of SLND for endometrial cancer patients. Literature published in the last five years (January 2015 to April 2020) was retrieved from PubMed, EMBASE, and Cochrane library, across five domains: (1) perioperative outcomes; (2) adjuvant treatment; (3) patient-reported outcomes (PROs); (4) lymphedema, and (5) cost. Covidence software ascertained a standardised and monitored review process. We identified 21 eligible studies. Included studies were highly heterogeneous, with widely varying outcome measures and reporting. SLND was associated with shorter operating times and lower estimated blood loss compared to systematic LND, but intra-operative and post-operative complications were not conclusively different. There was either no impact, or a trend towards less adjuvant treatment used in patients with SLND compared to systematic LND. SLND had lower prevalence rates of lymphedema compared to systematic LND, although this was shown only in three retrospective studies. Costs of surgical staging were lowest for no node sampling, followed by SLND, then LND. PROs were unable to be compared because of a lack of studies. The quality of evidence on patient-centred outcomes associated with SLND for surgical staging of endometrial cancer is poor, particularly in PROs, lymphedema and cost. The available studies were vulnerable to bias and confounding.

Registration of Systematic Review: PROSPERO (CRD42020180339)

Paraaortic sentinel lymph node detection in intermediate and high-risk endometrial cancer by transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR)

Objective

We aimed to evaluate the accuracy of sentinel lymph node (SLN) mapping with transvaginal ultrasound-guided myometrial injection of radiotracer (TUMIR) to detect lymph node (LN) metastases, in patients with intermediate and high-risk endometrial cancer (EC), focusing on its performance to detect paraaortic involvement.

Methods

Prospective study including women with preoperative intermediate or high-risk EC, according to ESMO-ESGO-ESTRO consensus, who underwent SLN mapping using the TUMIR approach. SLNs were preoperatively localized by planar and single photon emission computed tomography/computed tomography images, and intraoperatively by gamma-probe. Immediately after SLN excision, all women underwent systematic pelvic and paraaortic lymphadenectomy by laparoscopy.

Results

The study included 102 patients. The intraoperative SLN detection rate was 79.4% (81/102). Pelvic and paraaortic drainage was observed in 92.6% (75/81) and 45.7% (37/81) women, respectively, being exclusively paraaortic in 7.4% (6/81). After systematic lymphadenectomy, LN metastases were identified in 19.6% (20/102) patients, with 45.0% (9/20) showing paraaortic involvement, which was exclusive in 15.0% (3/20). The overall sensitivity and negative predictive value (NPV) of SLNs by the TUMIR approach to detect lymphatic involvement were 87.5% and 97.0%, respectively; and 83.3% and 96.9%, for paraaortic metastases. After applying the MSKCC SLN mapping algorithm, the sensitivity and NPV were 93.8% and 98.5%, respectively.

Conclusion

The TUMIR method provides valuable information of endometrial drainage in patients at higher risk of paraaortic LN involvement. The TUMIR approach showed a detection rate of paraaortic SLNs greater than 45% and a high sensitivity and NPV for paraaortic metastases in women with intermediate and high-risk EC.

Sentinel node mapping using indocyanine green and near-infrared fluorescence imaging technology for endometrial cancer: A prospective study using a surgical algorithm in Indian patients

Background:

Indocyanine green (ICG) fluorescence with high-definition, three-dimensional imaging systems is emerging as the latest strategy to reduce trauma and improve surgical outcomes during oncosurgery.

Materials and Methods:

This is a prospective study involving 100 patients with carcinoma endometrium who underwent robotic-assisted Type 1 pan-hysterectomy, with ICG-directed sentinel lymph node (SLN) biopsy from November 2017 to December 2019. The aim was to assess the feasibility and diagnostic accuracy of SLN algorithm and to evaluate the location and distribution of SLN in pelvic, para-aortic and unusual areas and the role of frozen section.

Results:

The overall SLN detection rate was 98%. Bilateral detection was possible in 92% of the cases. Right side was detected in 98% of the cases and left side was visualised in 92% of the cases. Complete node dissection was done where SLN mapping failed. The most common location for SLN in our series was obturator on the right hemipelvis and internal iliac on the left hemipelvis. SLN in the para-aortic area was detected in 14% of cases. In six cases, SLN was found in atypical locations, that is pre-sacral area. Eight patients had SLN positivity for metastasis and underwent complete retroperitoneal lymphadenectomy. Comparison of final histopathological report with frozen section reports showed no false negatives.

Conclusions:

SLN mapping holds a great promise as a modern staging strategy for endometrial cancer. In our experience, cervical injection was an optimal method of mapping the pelvis. ICG showed a high overall detection rate, and bilateral mapping appears to be a feasible alternative to the more traditional methods of SLN mapping in patients with endometrial cancer. The ICG fluorescence imaging system is simple and safe and may become a standard in oncosurgery in view of its staging and anatomical imaging capabilities. This approach can reduce the morbidity, operative times and costs associated with complete lymphadenectomy while maintaining prognostic and predictive information.

Assessment of Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging

Question

What is the diagnostic accuracy of sentinel lymph node biopsy (SLNB) compared with lymphadenectomy in women with intermediate- and high-grade endometrial cancer?

Findings

In this cohort study of 156 patients with endometrial cancer (126 with high-grade histologic subtypes), SLNB had a sensitivity of 96% and a negative predictive value of 99% for the detection of nodal metastasis. A total of 26% of patients with node-positive cancer were identified outside lymphadenectomy boundaries or required immunohistochemistry for diagnosis.

Meaning

In this study, SLNB had similar diagnostic accuracy and prognostic ability as lymphadenectomy in patients with high-grade endometrial cancer at greatest risk for nodal metastasis.

Importance

Whether sentinel lymph node biopsy (SLNB) can replace lymphadenectomy for surgical staging in patients with high-grade endometrial cancer (EC) is unclear.

Objective

To examine the diagnostic accuracy of, performance characteristics of, and morbidity associated with SLNB using indocyanine green in patients with intermediate- and high-grade EC.

Design, Setting, and Participants

In this prospective, multicenter cohort study (Sentinel Lymph Node Biopsy vs Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging [SENTOR] study), accrual occurred from July 1, 2015, to June 30, 2019, with early stoppage because of prespecified accuracy criteria. The study included patients with clinical stage I grade 2 endometrioid or high-grade EC scheduled to undergo laparoscopic or robotic hysterectomy with an intent to complete staging at 3 designated cancer centers in Toronto, Ontario, Canada.

Exposures

All patients underwent SLNB followed by lymphadenectomy as the reference standard. Patients with grade 2 endometrioid EC underwent pelvic lymphadenectomy (PLND) alone, and patients with high-grade EC underwent PLND and para-aortic lymphadenectomy (PALND).

Main Outcomes and Measures

The primary outcome was sensitivity of the SLNB algorithm. Secondary outcomes were additional measures of diagnostic accuracy, sentinel lymph node detection rates, and adverse events.

Results

The study enrolled 156 patients (median age, 65.5 years; range, 40-86 years; median body mass index [calculated as weight in kilograms divided by height in meters squared], 27.5; range, 17.6-49.3), including 126 with high-grade EC. All patients underwent SLNB and PLND, and 101 patients (80%) with high-grade EC also underwent PALND. Sentinel lymph node detection rates were 97.4% per patient (95% CI, 93.6%-99.3%), 87.5% per hemipelvis (95% CI, 83.3%-91.0%), and 77.6% bilaterally (95% CI, 70.2%-83.8%). Of 27 patients (17%) with nodal metastases, 26 patients were correctly identified by the SLNB algorithm, yielding a sensitivity of 96% (95% CI, 81%-100%), a false-negative rate of 4% (95% CI, 0%-19%), and a negative predictive value of 99% (95% CI, 96%-100%). Only 1 patient (0.6%) was misclassified by the SLNB algorithm. Seven of 27 patients with node-positive cancer (26%) were identified outside traditional PLND boundaries or required immunohistochemistry for diagnosis.

Conclusions and Relevance

In this prospective cohort study, SLNB had acceptable diagnostic accuracy for patients with high-grade EC at increased risk of nodal metastases and improved the detection of node-positive cases compared with lymphadenectomy. The findings suggest that SLNB is a viable option for the surgical staging of EC.

Sentinel lymph node biopsy in endometrial cancer: state of the art

Endometrial cancer (EC) is the most common gynecological neoplasm in developed countries. In literature, there are discordant data regarding the therapeutic value of systematic lymphadenectomy whereas the importance of lymph node status for determining prognosis and the need for adjuvant treatment is undoubted. Given the low risk of lymph-node metastases in the apparent early-stage disease and the significant surgical and postoperative risks when performing a complete pelvic lymphadenectomy, the surgical approach in these patients is controversial, ranging from no nodal evaluation to comprehensive pelvic and aortic lymphadenectomy. The recent introduction of sentinel node mapping represents the mid-way between the execution and omission of node dissection in EC patients. Indeed, the sentinel node mapping has rapidly emerged as an alternative to complete lymphadenectomy to reduce morbidity. In the present review, we discuss the role of sentinel node mapping in the surgical management of EC evaluating all aspects of this procedure.

Diagnostic Accuracy and Clinical Impact of Sentinel Lymph Node Sampling in Endometrial Cancer at High Risk of Recurrence: A Meta-Analysis

Purpose. To assess the value of sentinel lymph node (SLN) sampling in high risk endometrial cancer according to the ESMO-ESGO-ESTRO classification. Methods. We performed a comprehensive search on PubMed for clinical trials evaluating SLN sampling in patients with high risk endometrial cancer: stage I endometrioid, grade 3, with at least 50% myometrial invasion, regardless of lymphovascular space invasion status; or stage II; or node-negative stage III endometrioid, no residual disease; or non-endometrioid (serous or clear cell or undifferentiated carcinoma, or carcinosarcoma). All patients underwent SLN sampling followed by pelvic with or without para-aortic lymphadenectomy. Results. We included 17 original studies concerning 1322 women. Mean detection rates were 89% for unilateral and 68% for bilateral. Pooled sensitivity was 88.5% (95%CI: 81.2–93.2%), negative predictive value was 96.0% (95%CI: 93.1–97.7%), and false negative rate was 11.5% (95%CI: 6.8; 18.8%). We noted heterogeneity in SLN techniques between studies, concerning the tracer and its detection, the injection site, the number of injections, and the surgical approach. Finally, we found a correlation between the number of patients included and the SLN sampling performances. Discussion. This meta-analysis estimated the SLN sampling performances in high risk endometrial cancer patients. Data from the literature show the feasibility, the safety, the limits, and the impact on surgical de-escalation of this technique. In conclusion, our study supports the hypothesis that SLN sampling could be a valuable technique to diagnose lymph node involvement for patients with high risk endometrial cancer in replacement of conventional lymphadenectomy. Consequently, randomized clinical trials are necessary to confirm this hypothesis.

Utility of Intraoperative Fluorescence Imaging in Gynecologic Surgery: Systematic Review and Consensus Statement

BACKGROUND

This study aimed to review the current knowledge on the utility of intraoperative fluorescence imaging in gynecologic surgery and to give evidence-based recommendations to improve the quality of care for women who undergo gynecologic surgery.

METHODS

A computer-based systematic review of the MEDLINE, CENTRAL, Pubmed, EMBASE, and SciSearch databases as well as institutional guidelines was performed. The time limit was set at 2000-2019. For the literature search, PRISMA guidelines were followed. A modified-Delphi method was performed in three rounds by a panel of experts to reach a consensus of conclusions and recommendations.

RESULTS

Indocyanine green (ICG) is used primarily in gynecology for sentinel node-mapping. In endometrial and cervical cancer, ICG is a feasible, safe, time-efficient, and reliable method for lymphatic mapping, with better bilateral detection rates. Experience in vulvar cancer is more limited, with ICG used together with Tc-99 m as a dual tracer and alone in video endoscopic inguinal lymphadenectomy. In early ovarian cancer, results are still preliminary but promising. Indocyanine green fluorescence imaging also is used for ureteral assessment, allowing intraoperative ureteral visualization, to reduce the risk of ureteral injury during gynecologic surgery.

CONCLUSIONS

For most gynecologic cancers, ICG fluorescence imaging is considered the tracer of choice for lymphatic mapping. The use of this new technology expands to a better ureteral assessment.

Hysteroscopic versus cervical injection for sentinel node detection in endometrial cancer: A multicenter prospective randomised controlled trial from the Multicenter Italian Trials in Ovarian cancer (MITO) study group

AIM

During the last years, the role of sentinel lymph node mapping (SLNM) for endometrial cancer (EC) surgical treatment has increased in popularity. However, several controversies remain about different technical steps of SLNM. Thus, a randomised control trial was designed to compare cervical (CI) and hysteroscopic (HI) indocyanine green (ICG) injection for SLNM of newly diagnosed EC undergoing surgical staging. The primary end-point of the study was to compare these two techniques in terms of para-aortic detection rate.

METHODS

Patients with apparent stage I or II histologically confirmed EC undergoing surgery were included in the study. This randomised trial distinguished patients in two study groups according to two different techniques of ICG SLNM: CI versus HI injection. Patients who met the inclusion criteria were randomly assigned to CI or HI injection in a 1:1 ratio. The central randomisation system allocated patient randomisation numbers sequentially in the order in which the patients were enrolled. This randomised trial was not blinded for either patients or the surgeons.

RESULTS

From March 2017 until April 2019, a total of 165 patients were randomised in this study: 85 (51.5%) in the CI group and 80 (48.5%) in the HI group. After randomisation, 14 (8.5%) patients were excluded from the study. Finally, 151 patients were included in the analysis: 82 (54.3%) in the CI group and 69 (45.7%) in the HI group. Hysteroscopy injection shows an ability to detect Sentinel nodes (SNLs) in the para-aortic area of about 10% greater compared with CI injection, although this difference did not reach statistical significance. The HI technique was superior in detecting isolated para-aortic SLNs (5.8% Versus 0%). The CI injection was correlated with higher SLN detection rates at the pelvic level compared with HI injection. Pelvic and overall detection was higher in the CI group.

CONCLUSIONS

The present study supports the adoption of CI instead of HI injection because the former allows better identification of sentinel nodes (especially in the pelvic area). Detection of SLN in the para-aortic area was slightly higher in patients receiving a HI injection, but the difference with the CI route was not statistically significant.

The role of sentinel lymph node mapping in endometrial carcinoma

Endometrial cancer is the most commonly diagnosed gynecological malignancy in developing countries, and the second malignancy after cervical cancer in developing countries. The primary treatment is based on surgical and pathologic staging including extrafascial type A radical hysterectomy bilateral salpingo-oophorectomy and pelvic and latero-aortic lymphadenectomy. Minimally invasive surgery is the most widely used technique. Sentinel node biopsy is part of this concept and has reached the management of endometrial cancer. The aim of this review was to describe the history, the different injection techniques and results of sentinel node biopsy, and analyze the future role of this technique in endometrial carcinoma.

Para-aortic lymphadenectomy did not improve overall survival among women with type I endometrial cancer

OBJECTIVE

To compare outcomes and prognosis among women with type I endometrial cancer undergoing hysterectomy and bilateral salpingo-oophorectomy (H-BSO) with or without systematic pelvic lymphadenectomy (PLD) or para-aortic lymphadenectomy (PALD).

METHODS

Retrospective review of women postoperatively diagnosed with type I endometrial cancer who underwent H-BSO at a university hospital in Chengdu, China (January 2010 to June 2012). Women were divided into no lymphadenectomy (PLD-/PALD-), systematic pelvic lymphadenectomy (PLD+/PALD-), or combined pelvic and para-aortic lymphadenectomy (PLD+/PALD+) groups. Follow-up was by telephone. Postoperative outcomes and prognosis were compared and risk factors were analyzed.

RESULTS

In total, 333 women met the inclusion criteria: 121 underwent PLD+/PALD-, 166 underwent PLD+/PALD+, and 46 underwent PLD-/PALD-. There were no differences in pre-operative characteristics among the groups (all P>0.05). The PLD+/PALD+ group had a higher laparotomy rate (P=0.001), the PLD-/PALD- group had shorter operation time (P=0.001) and lower blood loss (P<0.001). There were no differences between the PLD+/PALD- and PLD+/PALD+ groups. Overall, 291 women had sufficient follow-up data; there was no difference in overall survival, and PALD was not a predictor of survival.

CONCLUSION

Postoperative outcomes were similar among all surgical groups; a survival benefit of PALD was not demonstrated.

UPDATE ON SENTINEL LYMPH NODE MAPPING IN ENDOMETRIAL CANCER PATIENTS WITH A HIGH RISK FOR NODAL METASTASIS

Surgery is the mainstay of treatment for the majority of patients diagnosed with endometrial carcinoma. Systematic lymphadenectomy has traditionally been considered a standard part of surgical therapy. More recently, however, the value of this has been a subject of much debate. The sentinel lymph node (SLN) mapping algorithm has emerged as an acceptable alternative to conventional pelvic and para-aortic lymph node dissection in endometrial cancer. Clinical trials have demonstrated the accuracy of SLN mapping in detecting nodal spread in patients with endometrial cancer. However, data regarding the oncological outcomes of this approach, particularly in the setting of endometrial cancer with a high risk of nodal spread, is still lacking. In this review, we provide an overview of SLN mapping in endometrial cancer. We will specifically discuss its use in patients with a high risk for nodal metastasis. Controversies and future directions for research will also be discussed.

Comparison of outcomes between the one-step and two-step sentinel lymph node mapping techniques in endometrial cancer

INTRODUCTION

Fluorescence image-guided sentinel lymph node (SLN) biopsy using a two-step mapping technique incorporates sequential injection of indocyanine green into the bilateral uterine cornus, followed by cervical injection. Outcomes were compared with the conventional cervical (one-step) method .

METHODS

Patients with FIGO stage I-III endometrial cancer who underwent laparoscopic or robotic staging, including SLN biopsy, from May 2014 to December 2018, were retrospectively reviewed. Patient characteristics, pre-operative imaging, SLN detection pattern, pathologic result, adjuvant, and recurrence locations were analyzed.

RESULTS

A total of 199 patients received one-step (n=123) and two-step (n=76) SLN biopsy. Para-aortic SLN were more frequently identified in the two-step group. Lower and upper para-aortic SLN were identified in 67.1% and 38.2%, respectively, in the two-step group and in 18.7% and 5.7% in the one-step group (p<0.001). The number of para-aortic SLN harvested was superior in the two-step group (p<0.001). Metastatic para-aortic SLN were found in 7.9% of the two-step group and 2.4% of the one-step group (p=0.070). In detecting nodal metastasis, the sensitivities of the one- and two-step methods were 91.7% and 100.0%, negative predictive values were 99.0% and 100.0%, false-negative rates were 8.3% and 0%, and accuracy rates were 99.1% and 100.0%, respectively. The one-step method identified only three out of eight para-aortic lymph node metastases and missed five para-aortic lymph node metastases. There was no missed para-aortic lymph node metastasis in the two-step group. Recurrence was observed in two patients (2.6%; vaginal vault and adrenal gland) in the two-step group and seven patients (5.7%) including three nodal recurrences in the one-step group (p=0.307).

DISCUSSION

Two-step SLN mapping improved the para-aortic SLN detection rate, a known pitfall of conventional cervical injection. Proper evaluation of aortic nodal status will assist in the tailoring of adjuvant and prevent undertreatment of patients with isolated para-aortic metastasis.

Robotic sentinel lymph node (SLN) mapping in endometrial cancer: SLN symmetry and implications of mapping failure

PURPOSE

To establish the bilateral pelvic concordance rate of the sentinel lymph node (SLN) and determine the likelihood of lymph node metastasis in cases of mapping failure.

METHODS

A database analysis was performed on 414 patients with clinical stage I endometrial cancer who underwent SLN mapping followed by robotic hysterectomy and completion pelvic (n=414, 100%) and aortic (n=186, 44.9%) lymphadenectomy from March 2011 to August 2016. Stage, histology, SLN sites, and surgico-pathologic findings were analyzed. The bilateral concordance rate of SLN location, successful unilateral and bilateral mapping rates, false negative rate, and non-SLN metastasis associated with mapping failure were calculated.

RESULTS

Histologies included 354 (85.5%) endometrioid, 39 (9.4%) serous, 16 (3.9%) carcinosarcoma, 4 (1.0%) clear cell, and 1 (0.2%) undifferentiated. Final stages included 262 (63.3%) IA, 36 (8.7%) IB, 15 (3.6%) II, 6 (1.4%) IIIA, 68 (16.4%) IIIC1, and 27 (6.5%) IIIC2. Bilateral SLN mapping was successful in 355 (85.7%) patients, and 266 (74.9%) demonstrated mapping to the symmetrical lymphatic group contralaterally. The mapping failure rate was 13.5% (56/414) unilaterally and 0.7% (3/414) bilaterally. SLN locations were external iliac (69.1%), obturator (25.1%), internal iliac (2.2%), common iliac (1.9%), pre-sacral (0.9%), aortic (0.4%), parametrial (0.3%), and para-rectal (0.1%). Lymph node metastases were identified in 95 (22.9%) pelvic and 27 (6.5%) aortic nodes. 10 (16.9%) cases with mapping failure had lymph node metastasis on completion lymphadenectomy, similar to the proportion of SLNs with metastases (p=0.35). However, macro-metastases were more common in mapping failure completion lymphadenectomies than in the positive SLNs (80% vs 22.3%, p<0.001).

CONCLUSION

The contralateral SLN location concordance rate was 75%. Most SLNs were along the medial external iliac or obturator locations. The rate of positive lymph nodes associated with SLN mapping failure was 16.9%, similar to the overall node-positive rate. The detection of pelvic node metastasis with SLN mapping failure was largely populated with macro-metastases and confirms the necessity of completion lymphadenectomy with mapping failure.

A Prospective Study of Sentinel Lymph Node Mapping for Endometrial Cancer: Is It Effective in High-Risk Subtypes?

BACKGROUND

The efficacy of sentinel lymph node (SLN) mapping for high-risk endometrial cancer remains unclear. This prompted us to evaluate the sensitivity, negative predictive value (NPV), and false-negative (FN) rate of cervical injection of indocyanine green (ICG) SLN mapping in patients with endometrial cancer.

MATERIALS AND METHODS

This prospective interventional study was performed at a single university teaching hospital. Consecutive patients with early-stage endometrial cancer who underwent laparoscopic surgical staging were included. Cervical injection of ICG and near-infrared SLN identification and biopsy were performed for all study patients followed by systematic pelvic lymphadenectomy, whereas para-aortic lymphadenectomy was performed in all patients with high-risk histologies. SLN detection rates, sensitivity, NPV, and FN rates were calculated.

RESULTS

Between July 2016 and July 2018, 131 patients were enrolled. The overall SLN detection rate was 93.1%, with a bilateral detection rate of 61.8%. Four positive SLNs were identified in four patients. Lymph node metastasis was observed in four additional patients without positive SLNs. These four patients belonged to a group of patients with a high-risk subtype. Three of the four patients had isolated para-aortic node metastases. In low-risk endometrial cancers, the sensitivity of the SLN technique to identify nodal metastatic disease was 100% (95% confidence interval [CI] 31.0-100), with an NPV and FN rate of 100% (95% CI 95.1-100) and 0%, respectively. In high-risk endometrial cancers, the sensitivity, NPV, and FN rate were 20% (95% CI 1.0-70.1), 83.3% (95% CI 61.8-94.5), and 80%, respectively.

CONCLUSION

Cervical injection of ICG and SLN mapping yielded a low sensitivity and a high FN rate for the identification of node metastasis in endometrial cancer with high-risk histologies.

IMPLICATIONS FOR PRACTICE

The efficacy of sentinel lymph node (SLN) mapping for high-risk endometrial cancer remains unclear. This study enrolled 131 patients with early-stage endometrial cancer who underwent cervical injection of indocyanine green SLN mapping followed by systematic pelvic lymphadenectomy and para-aortic lymphadenectomy. The key result was that SLN mapping yielded a low sensitivity and a high false-negative rate for the identification of node metastasis in endometrial cancer with high-risk histologies. The SLN strategy in these patients may increase the risk of missed diagnosis of isolated para-aortic node metastases and seems to be unacceptable in clinical practice.

Clinical management of early-stage cervical cancer: The role of sentinel lymph node biopsy in tumors ≤2 cm

OBJECTIVE

To evaluate the experience with sentinel lymph node (SLN) biopsy in patients with early-stage cervical cancer at our hospital, and to analyze factors influencing the rate of false negatives.

STUDY DESIGN

This study was carried out at the Vall d'Hebron Hospital (Barcelona, Spain) between September 2000 and October 2016. All patients underwent SLN biopsy and systematic and bilateral pelvic lymphadenectomy, followed by radical hysterectomy. SLNs were analyzed by the pathologist by staining with hematoxylin-eosin and immunohistochemistry.

RESULTS

Patients (N = 128) had been diagnosed with early-stage cervical cancer (FIGO-2009 stages 1A2, IB1, and IIA1). The combined SLN detection rate (99-technecium and a blue dye) was 98.4%, bilateral in 76% of the patients. Positive SLNs were found in 19 patients (14.8%). Sensitivity of detection was 79.2% (CI95, 57.9-92.9), false negative rate 20.8% (CI95, 7.1-42.2), and negative predictive value 95.4% (CI95, 89.6-98.5). False negative cases were observed in 5 patients with tumors >2 cm and presenting lymphovascular space invasion. Micrometastases were detected during SLN ultrastaging in 3 patients (2.3%). The median follow-up was 8.24 years and the 5-year overall survival (OS) was 88.4% (CI95, 80.9-93.1).

CONCLUSION

SLN mapping and biopsy in early-stage cervical cancer is feasible and has high sensitivity to detect patients with initial metastases. The risk of false negatives could be lower in certain groups of patients, such as those with tumors ≤2 cm and no lymphovascular space invasion, but future studies will be required to test this hypothesis.

The Basics of Sentinel Lymph Node Biopsy: Anatomical and Pathophysiological Considerations and Clinical Aspects

Sentinel lymph node (SLN) is the first node to receive the drainage directly from a tumor. Detection and pathological examination of the SLN is an important oncological procedure that minimizes morbidity related to extensive nodal dissection. SLN biopsy was first reported in 1960 but took approximately 40 years to come into general practice following reports of good outcomes in patients with melanoma. After many years of observation and research on its use in various malignancies SLN biopsy has become the standard surgical treatment in patients with malignant melanoma, breast, vulvar, and cervical cancers. Along with the introduction of new technologies, such as the fluorescent dyes indocyanine green (ICG) and near-infrared fluorescence (NIR), and pathologic ultrastaging, SLN detection rate has increased and false-negative rate has decreased. This literature review aimed to present an overview of the basic concepts and clinical aspects of SLN biopsy in the light of the current research.