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

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.

Role of sentinel lymph node biopsy with indocyanine green and site of injection in endometrial cancer

PURPOSE OF REVIEW

The aim of the present narrative review is to summarize the state of art on sentinel lymph node biopsy (SLNB) in endometrial cancer, with a special focus on indocyanine green (ICG) as adopted tracer.

RECENT FINDINGS

Over the years, the surgical nodal staging in patients with endometrial cancer has been intensively investigated. Traditionally, systematic pelvic and para-aortic lymphadenectomy represented the gold standard surgical treatment to assess nodal involvement of the tumor. Through the last two decades, SLNB has gradually replaced lymphadenectomy as a more targeted procedure. A great heterogeneity of tracers and injection techniques have been proposed to perform SLNB. However, no universally accepted recommendations are still available.

SUMMARY

SLNB has nowadays almost replaced pelvic lymphadenectomy in low-risk endometrial cancers, offering a better safety profile while being related to a comparable nodal involvement sensitivity. Currently, ICG is considered to be the most used tracer among others. Different injection sites have been proposed, with different detection features. While ICG cervical injection is nowadays the suggested technique for SLNB, noncervical injection techniques, such as hysteroscopic and combined procedures, seem to have a better accuracy in para-aortic nodal assessment, which have a role in high-risk endometrial cancers.

Comparison of Single-Port Laparoscopy with Other Surgical Approaches in Endometrial Cancer Surgical Staging: Propensity-Score-Matched Analysis

This single-institution, retrospective study aimed to compare the surgical outcomes of single-port, multi-port, and robot-assisted laparoscopy, as well as laparotomy, in patients with endometrial cancer who underwent surgical staging between January 2006 and December 2017. This study evaluated various parameters, including disease-free survival (DFS), overall survival (OS), recurrence rate (RR), recurrence site, and intra- and postoperative complications. Propensity score matching was performed to account for baseline characteristics, and a total of 881 patients were included in the analysis. The 3-year DFS of single-port laparoscopy was similar to that of the other groups, but laparotomy exhibited a lower 3-year DFS compared to multi-port (p = 0.001) and robot-assisted (p = 0.031) laparoscopy. Single-port laparoscopy resulted in a significantly higher 3-year OS than laparotomy (p = 0.013). After propensity score matching, the four groups demonstrated similar survival outcomes (3-year DFS: p = 0.533; 3-year OS: p = 0.328) and recurrence rates (10.3%, 12.1%, 10.3%, and 15.9% in the single-port, multi-port, and robot-assisted laparoscopy and laparotomy groups, respectively, p = 0.552). Recurrence most commonly occurred in distant organs. The single-port laparoscopy group had the longest operative time (205.1 ± 76.9 min) but the least blood loss (69.5 ± 90.8 mL) and the shortest postoperative hospital stay (5.2 ± 2.3 days). In contrast, the laparotomy group had the shortest operative time (163.4 ± 51.0 min) but the highest blood loss (368.3 ± 326.4 mL) and the longest postoperative hospital stay (10.3 ± 4.6 days). The transfusion rate was 0% in the single-port laparoscopy group and 3.7% in the laparotomy group. Notably, the laparotomy group had the highest wound complication rate (p = 0.001), whereas no wound hernias were observed in the three minimally invasive approaches. In conclusion, the survival outcomes were comparable between the methods, with the benefit of lower blood loss and shorter hospital stay observed in the single-port laparoscopy group. This study suggests that single-port laparoscopy is a feasible approach for endometrial cancer surgical staging.

Comparison of progression-free survival outcome of sentinel node biopsy without ultrastaging versus lymphadenectomy in endometrial cancer: a propensity-matched analysis

OBJECTIVE

We aimed to investigate the oncologic outcomes of patients with endometrial cancer who underwent sentinel lymph node (SLN) biopsy without ultrastaging compared with that of those who underwent lymphadenectomy (LND).

METHODS

Patients with endometrial cancer who underwent staging with SLN biopsy or LND during 2006 - 2021 were analyzed using propensity score matching (PSM). SLN metastasis was examined using hematoxylin and eosin staining, without ultrastaging. Progression-free survival (PFS) was compared between the two groups before and after PSM using age, histology, and stage as covariates. Clinical variables such as recurrence patterns and lymphatic complications, were assessed.

RESULTS

After excluding 213 patients who underwent validation LND with SLN biopsy, 902 were identified. The demographics of the remaining patients differed according to histology, myometrial invasion depth, and stage. Lymph node metastasis was less frequent in the SLN group than in the LND group (9.4% vs. 3.8%, p=0.004). The recurrence rates within 2 years were lower in the SLN group. The SLN group exhibited significantly superior 2-year and overall PFS than the LND group. Among patients with uterus-confined disease, overall PFS was favorable for SLN biopsy. After matching, differences in PFS were no longer observed, although the lymphocele and lymphedema rates were significantly lower in the SLN group.

CONCLUSION

In patients with endometrial cancer, SLN biopsy without ultrastaging did not compromise survival outcomes and was associated with significantly reduced lymphatic complication rates compared with LND. Therefore, SLN biopsy can be recommended for patients with endometrial cancer without definitive preoperative evidence of distant metastasis.

Surgical technique of two-step pelvic and para-aortic sentinel lymph node mapping in early-stage endometrial cancer: laparoscopic, robotic, and open method

Since sentinel lymph node mapping in endometrial cancer is becoming more widely used, the need of standardizing surgical technique is growing [1, 2]. The objective of this surgical video is to describe the procedure of two-step pelvic and para-aortic sentinel lymph node mapping using indocyanine green and fluorescent camera in endometrial cancer, in three versions of surgical modality of laparoscopic, robotic, and open laparotomy. The patients in the surgical video are diagnosed with biopsy-proven endometrial cancer in its early stage determined by the preoperative imaging study. After collecting washing cytology, bilateral salpinges were clamped with Endo Clip™ to minimize tumor spillage. Gauze packing in posterior cul-de-sac was done to minimize the spillage of indocyanine green dye during paraaortic sentinel lymph node mapping. Indocyanine green dye was injected in bilateral uterine fundus, to detect isolated paraaortic sentinel lymph node pathway. After bilateral paraaortic sentinel lymph node was sampled, cervical injection of Indocyanine green dye was done in 3 o'clock and 9 o'clock directions, both superficially and deeply, 2 mL in each side. After dissecting off the obliterated umbilical ligament, para-vesical and para-rectal spaces were developed. The ureter, uterine artery, and internal and external iliac vessels were identified before bilateral pelvic sentinel lymph nodes were sampled. Asan Medical Center's Institutional Review Board exempted this project. Sentinel paraaortic and pelvic lymph nodes were successfully harvested by two-step method of sentinel lymph node mapping through laparoscopic, robotic, and open laparotomy methods. This surgical video provides specific steps of pelvic and para-aortic sentinel lymph node mapping.

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.

Sentinel lymph node biopsy in high-risk endometrial cancer: performance, outcomes, and future avenues

Endometrial cancer is the second most common gynecological malignancy worldwide, with an overall favorable prognosis. However, a subgroup of patients has a high risk of recurrence and poor prognosis. This review summarizes recently published articles that examined sentinel lymph node (SLN) biopsy in patients with high-risk endometrial cancer. We focused on the performance and outcomes of SLN biopsy, and examined potential methods for improving the management of this high-risk subset. Few studies have examined the long-term outcomes of SLN in patients with high-risk endometrial cancer. Thus, we reviewed recently published retrospective studies that have adopted statistical techniques, such as inverse probability weighting or propensity score matching, to examine the outcome of SLN biopsy compared to conventional lymphadenectomy. Potential avenues for future research to fine-tune decision making for this patient subgroup were also discussed.

Usefulness and potential pitfalls of pre-operative PET-CT in patients with endometrial cancer undergoing one- and two-step sentinel lymph node mapping: Do negative findings on PET-CT negativity really indicate node negativity?

OBJECTIVE

We investigated the utility of Positron emission tomography-Computed tomography (PET-CT) in the setting of two different sentinel lymph node (SLN) mapping techniques; the conventional cervical injection method (one-step) and the two-step method, which involves fundal injection followed by cervical injection.

METHODS

Patients with endometrial cancer undergoing FDG PET-CT followed by laparoscopic or robotic surgical staging with SLN mapping at the Yonsei Cancer Center between July 2014 and April 2021 were stratified into the PET-positive group (with suspected or likely lymph nodes metastasis) and PET-negative group. A chart review was performed for the number of harvested SLNs, patterns of SLN metastases, and recurrence.

RESULTS

Among 466 patients undergoing one-step (n = 276) and two-step (n = 190) SLN mapping, LN metastasis was identified in 21 of 434 PET-negative and 18 of 32 PET-positive patients. The sensitivity and specificity of PET-CT for diagnosing lymph node metastasis were 46.2% and 96.7%, respectively. Among PET-positive patients with LN metastasis, anatomical distribution was concordant in 14/18 patients (77.8%). Among PET-negative patients, four (2.3%) had metastatic para-aortic SLNs, including three (1.7%) with isolated para-aortic metastases; metastatic para-aortic SLNs were exclusively found in the two-step group. Among PET-positive patients, para-aortic SLN metastasis was identified in 35.7% of two-step and 16.7% of one-step group. Among the 21 PET false-negative patients, recurrence was seen in four patients (19%) after a median follow-up of 34 months (range: 7-70 months).

CONCLUSIONS

PET-CT served as a useful guide to clinicians with high anatomical concordance rate in patients with LN metastasis. However, despite high specificity, sensitivity was limited. SLN metastasis pattern, especially at the para-aortic level, indicates that the two-step SLN technique might be useful in PET-negative and PET-positive patients.

Robotic Staging of Cervical Cancer With Simultaneous Detection of Primary Pelvic and Secondary Para-Aortic Sentinel Lymph Nodes: Reproducibility in a First Case Series

Objective

Discrepancies exist among international guidelines on the surgical staging of para-aortic lymph nodes in locally advanced cervical cancer (LACC), varying from considering a para-aortic lymph node dissection, at least up to the inferior mesenteric artery, to a complete para-aortic lymph node dissection. In this study, we aim to assess the reproducibility of our recently reported robotic technique using indocyanine green for identifying besides primary pelvic sentinel lymph nodes (SLNs), secondary para-aortic SLNs in a first case-cohort of cervical cancer patients.

Methods

A retrospective case series of LACC patients with/without suspicious pelvic lymph nodes (LNs) on imaging (including two patients with an additional suspicious para-aortic LN) is reported. All patients underwent a robotic pelvic SLN and para-aortic sentinel/nonsentinel LN dissection using the da Vinci Xi platform. Indocyanine green was used as a fluorescent tracer, at a concentration of 1.9 mg/mL, and injected as 0.5 mL in each quadrant of the cervix.

Results

In a total of 10 cases, primary pelvic SLNs (90% bilateral) with subsequent secondary para-aortic SLNs were identified in all cases. Lower para-aortic SLNs were present in all cases, and upper para-aortic SLNs were found in 9 out of 10 cases. The mean age of the cervical cancer patients was 49.8 years (SD ± 6.89), and the mean body mass index (BMI; kg/m²) was 23.96 (SD ± 4.60). The median total operative time was 105.5 min (range: 89–141 min). The mean numbers of primary pelvic SLNs and secondary lower and upper para-aortic SLNs were 3.10 (SD ± 1.10), 2.90 (SD ± 0.74), and 2.30 (SD ± 1.57), respectively. The median number of total para-aortic LNs (PALNs) dissected per patient was 11.5. Six patients had positive primary pelvic SLNs, and two had secondary positive para-aortic SLNs. The nonsentinel para-aortic LNs were negative in all cases. There were no intra- or postoperative complications.

Conclusion

Our preliminary experience demonstrates the reproducibility of identifying, besides primary pelvic SLNs, secondary lower and upper para-aortic SLNs during robotic staging in LACC. A surgical approach limiting a complete para-aortic LN dissection could reduce the potential risks and morbidity associated with this procedure. To determine the sensitivity and negative predictive value of this new surgical approach, and whether the lower para-aortic SLNs under the inferior mesenteric artery are representative of the whole para-aortic region, large prospective observational studies are needed in LACC and/or those with suspicious pelvic LNs but apparent normal para-aortic LNs on imaging.

Indocyanine green guidance for combined robotic pelvic and para-aortic sentinel node mapping in cervical cancer

BACKGROUND

Indocyanine green (ICG) for pelvic sentinel lymph node (SLN) mapping is well established in endometrial cancer (Persson et al., 2019 Jul). However, the application for para-aortic SLNs is less reported; and the detection rate of para-aortic SLNs, mainly after cervical injection of ICG, varies between 14% and 71% (Rossi et al., 2013 Nov; Kim et al., 2020 Mar; Gallotta et al., 2019 Mar). One recent report differentiates between lower and upper para-aortic SLNs in endometrial cancer (Kim et al., 2020 Mar). Here we describe a technique using ICG for identifying pelvic SLNs, lower and upper para-aortic SLNs in cervical cancer.

VIDEO

A 46-year old female presented with high grade cervical dysplasia/carcinoma in situ on cervical smear. Cervical cone biopsy revealed a grade two squamous cell carcinoma (depth of invasion 6.8mm, width 20.8mm). Clinically she was staged as an early FIGO-stage IB2 cervical cancer. NMR revealed bilaterally enlarged iliac lymph nodes. Additional PET-CT revealed FDG-uptake in the enlarged pelvic lymph nodes. In view of the imaging findings a staging Robotic pelvic and para-aortic SLN procedure was planned, prior to select the primary treatment (radical hysterectomy or chemo-radiation). ICG was injected into the cervical stroma, and a robotic pelvic and para-aortic SLN dissection (using Firefly System ®, Intuitive Surgical Inc.) was initiated 15 minutes and 35 minutes, respectively, after cervical injection.

RESULTS

This video demonstrates the application of ICG for mapping bilateral primary pelvic SLNs, secondary and tertiary para-aortic SLNs in the lower and upper para-aortic region respectively, in cervical cancer. Pathology revealed one metastatic pelvic SLN on the left side, other four pelvic SLNs were negative; both the secondary/lower (n = 3) and tertiary/upper (n = 5) para-aortic SLNs were negative, as well as the non-SLNs (n = 8).

CONCLUSION

The application of ICG for para-aortic SLN mapping should further be investigated and validated in staging surgically locally advanced cervical cancer and those with suspicious lymph nodes on imaging.

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.

The efficiency of a combined injection technique for sentinel lymph node mapping in intermediate-high-risk endometrial cancer

BACKGROUND AND OBJECTIVES

Sentinel lymph node (SLN) mapping was considered for treating endometrial cancer (EC) which was apparent confined to the uterus. Nevertheless, intermediate-high-risk EC patients have super high risk to undergo isolated para-aortic lymph node metastases comparing with low-risk patients. Therefore, this investigation aimed to compare the efficacy of two SLN methods in detecting para-aortic lymph node metastases.

METHODS

According to SLN mapping injection methods, intermediate-high-risk EC patients who received both SLN mapping and systematic lymphadenectomy were divided into the combined group (fundal and cervical injections) and the cervical group (cervical injection only).

RESULTS

The para-aortic SLN detection rate in the combined group (40.4%) was higher than that in the cervical group (4.4%) with p < 0.001. While the differences concerning the sensitivity, false-negative rate, and negative predictive value between the two groups were not significant. The survival outcomes of patients were comparable between the two groups.

CONCLUSION

Our data showcased that the combined (fundal and cervical) injection had a higher detection rate of para-aortic SLNs than cervical injection only. The efficiency of SLN mapping and the survival outcomes were not significantly different between the two groups. Further investigations are warranted to assess the value of combined injection regarding SLN technique.

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.

Pattern of Lymph Node Metastasis in Endometrial Cancer: a Single Institution Experience

Surgical staging remains the standard primary treatment of endometrial cancer. Lymph node metastasis is the most important prognostic factor which helps in deciding adjuvant treatment. Extensive lymphadenectomy is associated with increased incidence of morbidity. The role of lymphadenectomy in surgical staging is still controversial especially in early stage disease. The surgico-pathological pattern of 155 patients with apparently stage 1 cancer endometrium who had undergone pelvic alone or pelvic and para-aortic lymph node dissection and its correlation to the grade of the tumour, myometrial infiltration and presence of peritoneal disease and incidence of peri-operative morbidity are analysed and described.