Diagnostic accuracy of sentinel node in endometrial cancer by using hysteroscopic injection of radiolabeled tracer

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.

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.

A multicenter noninferior randomized controlled study of sentinel lymph node biopsy alone versus sentinel lymph node biopsy plus lymphadenectomy for patients with stage I endometrial cancer, INSEC trial concept

BACKGROUND

Up to the present time, there has remained a lack of strong evidence as to whether sentinel lymph node biopsy can replace lymphadenectomy for early endometrial cancer. The traditional surgery for endometrial cancer includes pelvic lymphadenectomy and paraaortic lymph node resection, but complications often seriously affect patients' quality of life. Two randomized controlled trials with large samples have proved that lymphadenectomy does not improve the overall recurrence rate and survival rate of patients. On the contrary, it increases the incidence of complications and even mortality. The current trial is designed to clarify whether sentinel lymph node biopsy can replace lymphadenectomy for early endometrial cancer patients with negative lymph nodes.

METHODS

This study is a randomized, open-label, multicenter and non-inferiority controlled clinical trial in China. Potential participants will be patients with pathologically confirmed endometrial cancer at the Zhejiang Cancer Hospital, Jiaxing Maternity and Child Health Care Hospital, and the First Hospital of Jiaxing in China. The total sample size for this study is 722. Patients will be randomly assigned in a 1:1 ratio to two groups. Patients in one group will undergo sentinel lymph node biopsy + total hysterectomy + bilateral salpingo-oophorectomy ± paraaortic lymph node resection. Patients in the other group will undergo sentinel lymph node biopsy + total hysterectomy + bilateral salpingo-oophorectomy + pelvic lymphadenectomy ± paraaortic lymph node resection. The 3-year disease-free survival rate, overall survival rate, quality of life (use EORTC QLQ-C30 + QLQ-CX24), and perioperative related indexes of the two groups will be compared.

RESULTS

We expect to find that for patients with early endometrial cancer, the 3-year disease-free survival rate following sentinel lymph node biopsy with indocyanine green combined with near-infrared fluorescence imaging is similar to that following lymphadenectomy. The operation time, as well as incidence of pelvic lymphocyst, lymphedema of lower limb, and edema of vulva in patients who only undergo sentinel lymph node biopsy are expected to be significantly lower than in patients who undergo lymphadenectomy. The quality of life of patients who undergo sentinel lymph node biopsy alone will be significantly better than that of patients who undergo lymph node dissection.

CONCLUSION

This will prove that the prognosis of sentinel lymph node biopsy alone with indocyanine green combined with near-infrared fluorescence imaging is not inferior to that of sentinel lymph node biopsy plus lymphadenectomy for early stage endometrial cancer with negative nodal assessment intraoperatively. In addition, sentinel lymph node biopsy alone with indocyanine green combined with near-infrared fluorescence imaging results in fewer surgical complications and gives patients better quality of life.

TRIAL REGISTRATION

chictr.org.cn, ChiCTR1900023161. Registered 14 May 2019, http://www.chictr.org.cn/edit.aspx?pid=38659&htm=4 .

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.

Comparison of radio-isotope method with 99m technetium and near-infrared fluorescent imaging with indocyanine green for sentinel lymph node detection in endometrial cancer

BACKGROUND

We aimed to compare the detection rate of pelvic sentinel lymph node between the radio-isotope with 99m technetium (99mTc)-labeled phytate and near-infrared fluorescent imaging with indocyanine green in patients with endometrial cancer.

METHODS

This study included 122 patients who had undergone sentinel lymph node mapping using 99mTc and indocyanine green. In the radio-isotope method, sentinel lymph nodes were detected using uterine cervix 99mTc injections the day before surgery. Following injection, the number and locations of the sentinel lymph nodes were evaluated by lymphoscintigraphy. In addition, indocyanine green was injected into the cervix immediately before surgery.

RESULTS

The overall pelvic sentinel lymph node detection rate (at least one pelvic sentinel lymph node detected) was not significantly different between 99mTc (95.9% [117/122]) and indocyanine green (94.3% [115/122]). Similarly, the bilateral sentinel lymph node detection rate was not significantly different between 99mTc (87.7% [107/122]) and indocyanine green (79.5% [97/122]). More than two sentinel lymph nodes per unilateral pelvic lymph node were found in 12.3% (15/122) and 27% (33/122) of cases with 99mTc and indocyanine green, respectively, in the right pelvic side, and 11.5% (14/122) and 32.8% (40/122) of cases with 99mTc and indocyanine green, respectively, in the left pelvic side. indocyanine green showed that there were significantly more than two sentinel lymph nodes in either the left or right pelvic sentinel lymph nodes (P < 0.0001). There was a significant difference in the mean number of total pelvic sentinel lymph nodes between 99mTc (2.2) and indocyanine green (2.5) (P = 0.028) methods.

CONCLUSION

Although indocyanine green is useful for sentinel lymph node identification, we believe it is better to use it in combination with 99mTc until the surgeon is accustomed to it.

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.

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.

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.

Gynaecological Cancer Diagnostics: 99mTc-Cisplatin Complex as a Future Approach for Early, Prompt and Efficient Diagnosis of Gynaecological Cancer

BACKGROUND

Gynaecological cancers (GCCa) are common and have a significant mortality rate all over the world. Early diagnosis of cancer can play a key role in the treatment and survival of a patient. Identification, staging, treatment, and monitoring of gynaecological malignancies is being done successfully by nuclear medicines.

DISCUSSION

Currently, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) centered imaging techniques are being developed for use in patients with GCCa as a diagnostic tool. The present work elucidates several clinical studies on the use of radiopharmaceuticals, based on their effectiveness, in the early detection and management of GCCa. It also highlights the importance of reconsidering the biology for nuclear imaging as a future modality for early, rapid and efficient diagnosis of gynecological cancers. This comprehensive review is a part of our study designed to detect gynaecological cancers at an early stage using radionuclide complex, 99m Tc-Cisplatin.

CONCLUSION

This article summarizes the significance of radioscintigraphy such as single-photon emission computed tomography (SPECT) and PET for identification of GCCa in the experimental humans and animals.

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.

Cervical versus endometrial injection for sentinel lymph node detection in endometrial cancer: a randomized clinical trial

OBJECTIVE

To evaluate the relationship between pelvic/para-aortic sentinel lymph node status and two different injection sites of 99m-technetium (^99mTc)-labeled phytate in patients with endometrial cancer.

METHODS

This was a randomized controlled trial involving 81 patients with endometrial cancer. In the cervical group (n=40), injections of ^99mTc were performed at the 3 and 9 o'clock positions of the uterine cervix. In the endometrial group (n=41), ^99mTc was injected into the fundal endometrium using a transcervical catheter. Sentinel lymph nodes were detected through pre-operative lymphoscintigraphy and intra-operatively using a handheld gamma probe. All patients underwent complete pelvic and para-aortic lymphadenectomy procedures. Pathologic ultra-staging was performed with immunostaining for cytokeratin in sentinel lymph nodes after routine hematoxylin and eosin histological examinations. The primary endpoint was the estimation of detection rates, sensitivity, false-negative rates, negative predictive value, and analysis of the distribution of pelvic and para-aortic sentinel lymph nodes.

RESULTS

The rate of detection of at least one sentinel lymph node, sensitivity, and the negative predictive value was 80%, 66.6%, 96.6% for the cervical group and 85%, 66.6%, 96.9% for the endometrial group, respectively. False-negative sentinel lymph nodes were detected in one patient from each group . There was no significant difference between the groups in terms of total sentinel lymph node count, sentinel pelvic lymph node count, and pelvic bilaterality, but the para-aortic sentinel lymph node count was significantly higher in the endometrial group (p<0.001). Ultra-staging examination of the pelvic sentinel lymph nodes revealed isolated tumor cells in one patient from each group.

CONCLUSION

Transcervical endometrial tracer injection in endometrial cancer revealed similar pelvic but significantly higher para-aortic sentinel lymph node detection.

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.

Sentinel lymph node mapping in endometrial cancer: performance of hysteroscopic injection of tracers

OBJECTIVE

To report on the performance of hysteroscopic injection of tracers (indocyanine green (ICG) and technetium-99m (Tc-99m)) for sentinel lymph node (SLN) mapping in endometrial cancer.

METHODS

Single-center retrospective evaluation of consecutive patients who underwent SLN mapping following hysteroscopic peritumoral injection of tracer. Detection rate (overall/bilateral/aortic) diagnostic accuracy, and oncologic outcomes were evaluated.

RESULTS

A total of 221 procedures met the inclusion criteria. Mean patient age was 60 (range 28-84) years and mean body mass index was 26.9 (range 15-47) kg/m² . In 164 cases (70.9%) mapping was performed laparoscopically. The overall detection rate of the technique was 94.1% (208/221 patients). Bilateral pelvic mapping was found in 62.5% of cases with at least one SLN detected and was more frequent using ICG than with Tc-99m (73.8% vs 53.3%; p<0.001). In 47.6% of cases SLNs mapped in both pelvic and aortic nodes, and in five cases (2.4%) only in the aortic area. In eight patients (3.8%) SLNs were found in aberrant (parametrial/presacral) areas. Mean number of detected SLNs was 3.7 (range 1-8). In 51.9% of cases at least one node other than SLNs was removed. Twenty-six patients (12.5%) had nodal involvement: 12 (46.2%) macrometastases, six (23.1%) micrometastases, and eight (30.7%) isolated tumor cells. In 12 cases (46.8%) the aortic area was involved. Overall, 6/221 (2.7%) patients had isolated para-aortic nodes. Three false-negative results were found, all in the Tc-99m group. All had isolated aortic metastases. Overall sensitivity was 88.5% (95% CI 71.7 to 100.0) and overall negative predictive value was 96.5% (95% CI 86.8 to 100.0). There were 10 (4.8%) recurrences: five abdominal/distant, four vaginal, and one nodal (in the aortic area following a unilateral mapping plus side-specific pelvic lymphadenectomy). Most recurrences (9/10 cases) were patients in whom a completion lymphadenectomy was performed. No deaths were reported after a mean follow-up of 47.7 months.

CONCLUSIONS

Hysteroscopic injection of tracers for SLN mapping in endometrial cancer is as accurate as cervical injection with a higher detection rate in the aortic area. ICG improves the bilateral detection rate. Adding lymphadenectomy to SLN mapping does not reduce the risk of relapse.

Value of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and Sentinel Lymph Node Biopsy in Endometrial Cancer Patients: A Prospective Study

The aim of this study is to define the role of preoperative positron emission tomography/computed tomography (PET/CT) scan and sentinel lymph node (SLN) biopsy for nodal metastasis detection in Endometrial Cancer (EC) patients. From January 2014 to August 2016 patients affected by EC scheduled for surgery underwent PET/CT scan and SLN mapping with indocyanine-green. Patients with suspicious lymph nodes at FDG-PET/CT underwent selective pelvic lymphadenectomy. In case of undetectable SLN, no further lymphadenectomy was performed if PET/CT scan was negative. Basic descriptive statistics were used to describe outcomes. A total of 83 patients were enrolled in the study. PET/CT scan was suggestive of nodal involvement in 15 patients. SLN were detected bilaterally in 78% of patients. Detection rate was influenced by patients' BMI and surgical learning curve. Five patients were node-positive: all of these had hypermetabolic nodes on PET/CT scan; in one patient SLN was not detected. Ten out of 15 patients with suspicious nodes on PET/CT scan were node-negative. After a median follow up of 24 months all patients are alive. Four patients experienced recurrent disease. No nodal relapse was recorded. Lymphatic mapping with sentinel node biopsy is able to reduce morbidity associated with pelvic lymphadenectomy. Sentinel node assessment is a feasible and appealing procedure and should be performed in a specialized center. Detection rate strongly improves with learning curve, while is reduced in morbidly obese patients. PET/CT scan shows high sensitivity but moderate specificity for nodal metastasis and may help to avoid nodal dissection in patients with sentinel node mapping failure.

Preoperative Prediction of Lymph Nodal Metastases in Endometrial Carcinoma: Is it Possible?: A Literature Review

BACKGROUND

Lymph node status is one of the most important prognostic factors in endometrial cancer and crucial for deciding adjuvant therapy.

OBJECTIVE

The aim of the study was to assess the different models used to predict lymphatic nodal disease.

SEARCH STRATEGY

A literature search was conducted to detect the relevant studies.

INCLUSION CRITERIA

Relevant papers comparing the preoperative modality with the final histopathological results including randomized clinical trials, case-control studies, and any publications with a minimum of 50 patients in the report.

RESULTS

Molecular-based predictors are still far from a practical application. Preoperative radiological scans (positron emission tomography, computed tomography, magnetic resonance imaging, and ultrasound) have shown the best predictor of lymphatic dissemination. However, there is currently no ideal model available, which can be used within standard clinical care.

CONCLUSIONS

Surgical staging still remains the criterion standard in the determination of lymph node status in endometrial cancer.

A feasibility study of sentinel lymph node mapping by cervical injection of a tracer in Japanese women with early stage endometrial cancer

OBJECTIVE

The aim of this study was to investigate the feasibility of sentinel lymph node mapping characterized by a cervical tracer injection in endometrial cancer.

MATERIALS AND METHODS

This retrospective study was carried out using data for 57 patients with endometrial carcinoma who had undergone intraoperative sentinel lymph node mapping and subsequent surgical staging. Technetium colloid and/or indocyanine green was injected into the uterine cervix and a gamma-detecting probe and/or photodynamic eye camera system was used intraoperatively to locate hot spots.

RESULTS

Of the 57 patients, 52 (91.2%) had FIGO Stage I disease. Successful unilateral or bilateral mapping occurred in 54 patients (94.7%) and 46 (80.7%), respectively. The median number of sentinel lymph nodes detected was two (range, 0-5). Following sentinel lymph node mapping, 41 patients (71.9%) underwent pelvic lymphadenectomy alone and 16 (28.1%) full lymphadenectomy. The median number of lymph nodes resected was 17 (range, 8-110). Sentinel lymph nodes were involved in four patients (7.0%), two with macrometastases and two with low-volume metastases. The sensitivity and negative predictive value for detecting lymph node metastasis were both 100%.

CONCLUSION

Sentinel lymph node mapping with the use of cervical tracer injection is highly feasible in Japanese women with early stage endometrial cancer.

Where Are We Going with Sentinel Lymph Node Mapping in Gynecologic Cancers?

PURPOSE OF REVIEW

Sentinel lymph node (SLN) mapping is a standard of care for lymphatic assessment of many early-stage gynecologic malignancies. We review the current data, emphasizing the utility of SLN mapping in the management of gynecologic cancers.

RECENT FINDINGS

Endometrial cancer: recent studies have focused on confirming the safety and efficacy of SLN mapping for high-risk patients. Cervical cancer: the LACC Trial demonstrated reduced survival with minimally invasive surgery, calling into question the validity of prior studies evaluating SLN mapping with a minimally invasive approach. Vulvar cancer: the ongoing GROINS-V-II trial is investigating whether patients with SLN metastasis < 2 mm in diameter can safely undergo adjuvant radiation ± chemotherapy without completion inguinal lymphadenectomy. NCCN guidelines have incorporated SLN mapping as a lymphatic assessment strategy for endometrial, cervical, and vulvar malignancies. SLN mapping appears to reduce morbidity while still maintaining an appropriate detection rate of lymphatic metastasis. Additional clinical trials will further our knowledge of these procedures.

Two-step sentinel lymph node mapping strategy in endometrial cancer staging using fluorescent imaging: A novel sentinel lymph node tracer injection procedure

OBJECTIVE

The current sentinel lymph node (SLN) tracer injection procedure for endometrial cancer commonly uses cervical injection, which can detect SLNs of the uterine cervix but not the uterine body. This study describes an SLN tracer injection procedure, titled two-step SLN mapping, which can identify SLNs of the uterine body and cervix using fluorescent imaging with indocyanine green (ICG) and results of SLN biopsy.

METHODS

In 50 consecutive patients with endometrial cancer, two-step SLN mapping was performed during laparoscopic surgical staging with the PINPOINT® real-time fluorescence imaging system. The first step was to identify SLNs of the uterine body. In total, 4-6 mL of ICG was injected into the bilateral uterine cornual areas, and lymphatic channels were traced, followed by identification and removal of paraaortic SLNs. The second step was to identify SLNs of the uterine cervix by injecting 4 mL of ICG into the cervix. After harvesting the mapped pelvic SLNs, complete pelvic and paraaortic lymphadenectomy was performed to validate the two-step SLN mapping strategy.

RESULTS

Our two-step SLN mapping strategy produced excellent SLN detection rates: 100% (50/50) overall for SLNs; 98.0% (49/50) for pelvic SLNs; 94.0% (47/50) for bilateral SLNs; and 86.0% (43/50) for paraaortic SLNs. We detected microscopic metastasis in harvested SLNs of 4 patients (8.0%). The sensitivity, specificity, and negative predictive value of SLN detection were all 100%. There was no false negative case.

CONCLUSION

The two-step SLN mapping strategy to identify lymph nodes from the uterine fundus and cervix was feasible. This strategy could be more accurate in identifying paraaortic lymph node metastasis than the cervical injection method.

Description of a reproducible anatomically based surgical algorithm for detection of pelvic sentinel lymph nodes in endometrial cancer

OBJECTIVE

To describe and evaluate a reproducible, anatomically based surgical algorithm, including reinjection of tracer to enhance technical success rate, for detection of pelvic sentinel lymph nodes (SLNs) in endometrial cancer (EC).

METHODS

A prospective study of 102 consecutive women with high risk EC scheduled for robotic surgery was conducted. Following cervical injection of a fluorescent dye, an algorithm for trans- and retroperitoneal identification of tracer display in the lower and upper paracervical pathways was strictly adhered to. To enhance the technical success rate, this included ipsilateral reinjection of tracer in case of non-display of any lymphatic pathway. The lymphatic pathways were kept intact by opening the avascular planes. To minimize disturbance from leaking dye, removal of SLNs was first performed along the lower paracervical (presacral) pathways followed by the more caudal upper paracervical pathways. In each pathway, the juxtauterine node with an afferent lymph vessel was defined as an SLN. After removal of SLNs, a complete pelvic and, unless contraindicated, infrarenal paraaortic lymph node dissection was performed.

RESULTS

The bilateral detection rate including tracer reinjection was 96%. All 24 (23.5%) node positive patients had at least one metastatic SLN. Presacral lymph node metastases were discovered in 33.3% of the node positive patients. One patient (4.2%) had an isolated presacral lymph node metastasis.

CONCLUSIONS

The described cranial-to-caudal anatomically based surgical SLN algorithm, including a presacral dissection and reinjection of tracer, results in a high SLN detection rate and identified all patients with lymph node metastases.

Sentinel lymph node mapping in endometrial cancer: a systematic review and meta-analysis

Endometrial cancer is the most frequent tumor in the female reproductive system, while the sentinel lymph node (SLN) mapping for diagnostic efficacy of endometrial cancer is still controversial. This meta-analysis was conducted to evaluate the diagnostic value of SLN in the assessment of lymph nodal involvement in endometrial cancer. Forty-four studies including 2,236 cases were identified. The pooled overall detection rate was 83% (95% CI: 80-86%). The pooled sensitivity was 91% (95% CI: 87-95%). The bilateral pelvic node detection rate was 56% (95% CI: 48-64%). Use of indocyanine green (ICG) increased the overall detection rate to 93% (95% CI: 89-96%) and robotic-assisted surgery also increased the overall detection rate to 86% (95% CI: 79-93%). In summary, our meta-analysis provides strong evidence that sentinel node mapping is an accurate and feasible method that performs well diagnostically for the assessment of lymph nodal involvement in endometrial cancer. Cervical injection, robot-assisted surgery, as well as using ICG, optimized the sensitivity and detection rate of the technique. Sentinel lymph mapping may potentially leading to a greater utilization by gynecologic surgeons in the future.

Sentinel node mapping in endometrial cancer following Hysteroscopic injection of tracers: A single center evaluation over 200 cases

OBJECTIVES

To analyze detection-rate(DR) and diagnostic-accuracy (A) of sentinel-nodes(SLNs) mapping following hysteroscopic-injection of tracer. To compare DR and A between tracers: ICG and Tc99m.

METHODS

Evaluation of endometrial-cancer patients who underwent SLNs mapping after hysteroscopic-peritumoral-injection of tracer±lymphadenectomy. Analysis of DR (overall-bilateral-aortic) and A in the entire cohort and comparison between tracers.

RESULTS

202 procedures were performed from January/2005 to February/2017. Mean age:60years (28-82); mean BMI: 26.8 kg/m² (15-47). In 133 cases (65.8%) hysterectomy and mapping procedure were performed laparoscopically. The overall-DR of the technique was 93.2% (179/192) (10 cases were excluded: 9 for technical-equipment failure; 1 for vagal reaction). Bilateral pelvic mapping was found in 59.7% of cases (107/179) and was more frequent in the ICG group (72.8% vs 53.3%; p: 0.012). In 50.8% of cases (91/179) SLNs were mapped both in pelvic and aortic nodes, and in 5 cases (2.8%) only in the aortic area. The mean number of detected SLNs was 3.7 (1-8). 22 patients (12.3%) had nodal involvement: 10-(45.5%)-macrometastases; 5-(22.7%)-micrometastases; 7-(31.8%)-ITCs. In 6 cases (27.3%) only aortic nodes were positive; in 5 cases (22.7%) both pelvic and aortic nodes and in 11 cases (50%) only pelvic nodes were involved. Three false-negative results were found, all in the Tc99m group. All had isolated aortic metastases with negative pelvic nodes. Overall-sensitivity was 86.4% (95%CI: 68.4-100) and overall-negative-predictive-value (NPV) was 96.4% (95%CI 86.7-100). No differences in terms of overall-DR, overall-sensitivity and overall-NPV were found between the two tracers.

CONCLUSIONS

Hysteroscopic-injection of tracer for SLNs mapping in endometrial cancer is as accurate as cervical injection with a higher DR in the aortic area. ICG improves bilateral-DR. Further investigation is warranted on this topic.

Sentinel lymph node mapping and staging in endometrial cancer: A Society of Gynecologic Oncology literature review with consensus recommendations

The emphasis in contemporary medical oncology has been "precision" or "personalized" medicine, terms that imply a strategy to improve efficacy through targeted therapies. Similar attempts at precision are occurring in surgical oncology. Sentinel lymph node (SLN) mapping has recently been introduced into the surgical staging of endometrial cancer with the goal to reduce morbidity associated with comprehensive lymphadenectomy, yet obtain prognostic information from lymph node status. The Society of Gynecologic Oncology's (SGO) Clinical Practice Committee and SLN Working Group reviewed the current literature for preparation of this document. Literature-based recommendations for the inclusion of SLN assessment in the treatment of patients with endometrial cancer are presented. This article examines.

A prospective validation study of sentinel lymph node mapping for high-risk endometrial cancer

OBJECTIVE

Sentinel lymph node (SLN) mapping continues to evolve in the surgical staging of endometrial cancer (EC). The purpose of this trial was to identify the sensitivity, false negative rate (FNR) and FN predictive value (FNPV) of SLN compared to complete pelvic and para-aortic lymphadenectomy (LAD) in women with high-risk EC.

METHODS

Women with high-risk EC (grade 3, serous, clear cell, carcinosarcoma) were enrolled in this prospective surgical trial. All patients underwent preoperative PET/CT and intraoperative SLN biopsy followed by LAD. Patients with peritoneal disease on imaging or at the time of surgery were excluded. Patients were evaluable if SLN was attempted and complete LAD was performed.

RESULTS

123 patients were enrolled between 4/13 and 5/16; 101 were evaluable. At least 1 SLN was identified in 89% (90); bilateral detection 58%, unilateral pelvic 40%, para-aortic only 2%. Indocyanine green was used in 61%, blue dye in 28%, and blue dye and technetium in 11%. Twenty-three pts. (23%) had ≥1 positive node. In 20/23, ≥1 SLN was identified and in 19/20 the SLN was positive. Only 1 patient had bilateral negative SLN and positive non-SLNs on final pathology. Overall, sensitivity of SLN was 95% (19/20), FNR was 5% (1/20) and FNPV was 1.4% (1/71). If side-specific LAD was performed when a SLN was not detected, the FNR decreased to 4.3% (1/23).

CONCLUSION

This prospective trial demonstrated that SLN biopsy plus side-specific LAD, when SLN is not detected, is a reasonable alternative to a complete LAD in high-risk endometrial cancer.

Sentinel lymph node assessment in endometrial cancer: a systematic review and meta-analysis

BACKGROUND

In the staging of endometrial cancer, controversy remains regarding the role of sentinel lymph node mapping compared with other nodal assessment strategies.

OBJECTIVE

We conducted a systematic review to evaluate the diagnostic accuracy and clinical impact of sentinel lymph node mapping in the management of endometrial cancer.

DATA SOURCES

We searched Medline, Embase, and the Cochrane Central Registry of Controlled trials for studies published in English before March 25, 2016 (PROSPERO CRD42016036503).

STUDY ELIGIBILITY CRITERIA

Studies were included if they contained 10 or more women with endometrial cancer and reported on the detection rate, sensitivity, and/or impact on treatment or survival of sentinel lymph node mapping.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two authors independently reviewed abstracts and full-text articles for inclusion and assessed study quality. The detection rate, sensitivity, and factors associated with successful mapping (study size, body mass index, tumor histology and grade, injection site, dye type) were synthesized through random-effects meta-analyses and meta-regression.

RESULTS

We identified 55 eligible studies, which included 4915 women. The overall detection rate of sentinel lymph node mapping was 81% (95% confidence interval, 77-84) with a 50% (95% confidence interval, 44-56) bilateral pelvic node detection rate and 17% (95% confidence interval, 11-23) paraaortic detection rate. There was no difference in detection rates by patient body mass index or tumor histology and grade. Use of indocyanine green increased the bilateral detection rate compared with blue dye. Additionally, cervical injection increased the bilateral sentinel lymph node detection rate but decreased the paraaortic detection rate compared with alternative injection techniques. Intraoperative sentinel lymph node frozen section increased the overall and bilateral detection rates. The sensitivity of sentinel node mapping to detect metastases was 96% (95% confidence interval, 91-98); ultrastaging did not improve sensitivity. Compared with women staged with complete lymphadenectomy, women staged with sentinel lymph node mapping were more likely to receive adjuvant treatment.

CONCLUSION

Sentinel lymph node mapping is feasible and accurately predicts nodal status in women with endometrial cancer. The current data favors the use of cervical injection techniques with indocyanine green. Sentinel lymph mapping may be considered an alternative standard of care in the staging of women with endometrial cancer.

Accuracy of pre-operative hysteroscopic guided biopsy for predicting final pathology in uterine malignancies

PURPOSE

To evaluate concordance (C) between pre-operative hysteroscopic-directed sampling and final pathology in uterine cancers.

METHODS

A retrospective cross-sectional evaluation of prospectively collected data of women who underwent hysterectomy for uterine malignancies and a previous hysteroscopic-guided biopsy was performed. Diagnostic concordance between pre-operative (hysteroscopic biopsy) and postoperative (uterine specimen) histology was evaluated. In endometrioid-endometrial cancers cases Kappa (k) statistics was applied to evaluate agreement for grading (G) between the preoperative and final pathology.

RESULTS

A total 101 hysterectomies for uterine malignancies were evaluated. There were 23 non-endometrioid cancers: 7 serous (C:5/7, 71.4%); 10 carcinosarcomas (C:7/10, 70%, remaining 3 cases only epithelial component diagnosed); 3 clear cell (C:3/3, 100%); 3 sarcomas (C:3/3, 100%). In 78 cases an endometrioid endometrial cancer was found. In 63 cases there was a histological C (63/78, 80.8%) between hysteroscopic-guided biopsy and final pathology, while in 15 cases (19.2%) only hyperplasia (with/without atypia) was found preoperatively. Overall accuracy to detect endometrial cancer was 80.2%. In 50 out of 63 endometrial cancers (79.4%) grading was concordant. The overall level of agreement between preoperative and postoperative grading was "substantial" according to Kappa (k) statistics (k 0.64; 95% CI: 0.449-0.83; p < 0.001), as well as for G1 (0.679; 95% CI: 0.432-0.926; p < 0.001) and G3 (0.774; 94% CI: 0.534-1; p < 0.001), while for G2 (0.531; 95% CI: 0.286-0.777; p < 0.001) it was moderate.

CONCLUSIONS

In our series we found an 80% C between pre-operative hysteroscopic-guided biopsy and final pathology, in uterine malignancies. Moreover, hysteroscopic biopsy accurately predicted endometrial cancer in 80% of cases and "substantially" predicted histological grading. Hysteroscopic-guided uterine sampling could be a useful tool to tailor treatment in patients with uterine malignancies.

A study on uterine lymphatic anatomy for standardization of pelvic sentinel lymph node detection in endometrial cancer

OBJECTIVE

To describe the anatomy of uterine lymphatic drainage following cervical or fundal tracer injection to enable standardization of a pelvic sentinel lymph node (SLN) concept in endometrial cancer (EC).

METHODS

A prospective consecutive study of women with EC was conducted. A fluorescent dye (Indocyanine green) was injected into the cervix (n=60) or the uterine fundus (n=30). A systematic trans- and retroperitoneal mapping of uterine lymphatic drainage was performed. Positions of the pelvic SLNs, defined by afferent lymph vessels, and lymph node metastases were compared.

RESULTS

Two consistent lymphatic pathways with pelvic SLNs were identified irrespective of injection site; an upper paracervical pathway (UPP) with draining medial external and/or obturator lymph nodes and a lower paracervical pathway (LPP) with draining internal iliac and/or presacral lymph nodes. Bilateral display of at least one pelvic pathway following cervical and fundal injection occurred in 98% and 80% respectively (p=0.005). Bilateral display of both pelvic pathways occurred in 30% and 20% respectively (p=0.6) as the LPP was less often displayed. Nearly one third of the 19% node positive patients had metastases along the LPP. No false negative SLNs were identified.

CONCLUSIONS

Based on uterine lymphatic anatomy a bilateral detection of at least one SLN in both the UPP and LPP should be aimed for. Absence of display of the LPP may warrant a full presacral lymphadenectomy. Although pelvic pathways and positions of SLNs are independent of the tracer injection site, cervical injection is preferable due to a higher technical success rate.

Value of Sentinel Lymph Node (SLN) Mapping and Biopsy using Combined Intracervical Radiotracers and Blue Dye Injections for Endometrial Cancer

Background:

Lymphadenectomy, as part of the initial surgical staging of patients with endometrial carcinoma, remains a controversial topic in gynecologic oncology. Sentinel lymph node (SLN) mapping has become a well-accepted procedure for melanomas and breast cancer; a number of investigators have begun to explore the utility and accuracy of this technique with regard to endometrial cancer.

Aim:

This study was conducted to evaluate SLN mapping of early stage endometrial cancer with blue dye in conjunction with a radioactive tracer.

Subjects and methods:

In this prospective cross-sectional study, patients with stage I and II endometrial cancer who were candidates for systemic lymph node dissection during surgery were enrolled, some underwent lymph node mapping and SLN biopsy using combined intra cervical radiotracer and blue dye injections and some applying only an intra cervical radiotracer. SLNs and other lymph nodes were sent for pathological assessment. Sensitivity, specificity, the positive predictive value, and the negative predictive value were calculated as predictive values for the radiotracer and blue dye.

Results:

Pre-operative lymph node mapping showed SLN in 29 out of 30 patients. Intra operations in 29/30 patients, SLNs were harvested by gamma probe; in 13 out of 19 patients SLNs were detected by blue dye. The median number of SLNs per patient was 3 and the total number of SLNs detected was 81. Four patients had positive pelvic lymph nodes. All of the positive nodes were SLNs. Using this technique (radiotracer and blue dye) an overall detection rate of 96.7%, an NPV of 100%, a sensitivity of 100% and a specificity of 3.85% were achieved.

Conclusion:

Results of SLN research for endometrial cancer are promising and make feasible the possibility of avoiding unnecessary aggressive surgical procedures in near future by advances in SLN mapping.

Sentinel Lymph Node Biopsy in Pelvic Tumors: Clinical Indications and Protocols Under Investigation

Sentinel lymph node (SLN) sampling is an attractive alternative to complete lymphadenectomy. Based on the identification and sampling of the first LN draining a primary tumor, SLN biopsy is the most accurate and the only reliable method for microscopic nodal staging for solid tumors including breast cancer and melanoma. Lymph node status in pelvic tumors remains the most important prognostic factor for recurrence and survival and a major decision criterion for adjuvant therapy. We review the clinical indications, controversies, and perspective of SLN biopsy in male and female pelvic cancers.

Laparoscopic Sentinel Node Mapping in Endometrial Cancer After Hysteroscopic Injection of Indocyanine Green

STUDY OBJECTIVE

To report the detection rate (DR) of sentinel lymph nodes (SLNs) in endometrial cancer (EC) patients after hysteroscopic injection of indocyanine green (ICG) and laparoscopic near-infrared (L-NIR) fluorescence mapping.

DESIGN

Prospectively collected data (Canadian Task Force classification II-2).

SETTING

Gynecologic oncology referral center.

PATIENTS

Consecutive patients with apparent early-stage endometrioid EC scheduled for surgical treatment: total laparoscopic hysterectomy, bilateral salpingo-oophorectomy, SLN mapping.

INTERVENTIONS

The mapping technique consisted in an intraoperative hysteroscopic peritumoral injection of 5 mg ICG followed by L-NIR fluorescence mapping. Evaluations of the SLN DR and sites of mapping were performed.

MEASUREMENTS AND MAIN RESULTS

A total of 57 procedures was performed. Patient mean age was 60 years (range, 28-80) and mean body mass index was 28.2 kg/m² (range, 19-43). At least 1 SLN was detected in 89.5% of the whole population (51/57). After the first 16 cases, L-NIR camera technical improvement led to a 95% DR (39/41). The mean number of harvested SLNs was 4.1 (range. 1-8), and in 47% of cases SLNs mapped to aortic nodes (24/51). Bilateral pelvic mapping was found in 74.5% of cases (38/51). Three patients had SLN metastases: 1 in the pelvic area only, 1 both in the pelvic and aortic area, and 1 presented with 2 metastatic aortic SLNs with negative pelvic SLNs. Overall, 2 of 3 node-positive patients (67%) had aortic SLN involvement. No adverse events were reported.

CONCLUSIONS

Laparoscopic SLN mapping after the hysteroscopic injection of ICG has comparable DRs with both radioactive tracer series and ICG series with cervical injection, overcoming the need for radioactive substances. Hysteroscopic injection leads to a higher mapping in the aortic area compared with cervical injection. Further investigation is warranted on this topic.

The sentinel node approach in gynaecological malignancies

This review discusses the state-of-the-art of sentinel lymph node mapping in gynaecological malignancies, including cervical cancer, endometrial cancer, and vulvar cancer, with an emphasis on new technological advances. For this objective, PubMed/MEDLINE was searched for relevant studies about the sentinel lymph node procedure in gynaecology. In particular, the use of preoperative lymphatic mapping with lymphoscintigraphy and single photon emission tomography/computed tomography (SPECT/CT) was identified in 18 studies. Other recent advances as hybrid tracers (e.g. ICG-^99mTc-nanocolloid) and intraoperative tools (portable γ-camera and 3D navigation devices) appear to also represent a useful guide for the surgeon during the operation. Concerning vulvar and cervical cancers, the sentinel lymph node procedure has been incorporated to the current guidelines in Europe and North America, whereas for endometrial cancer it is considered investigative.

Sentinel Lymph Node Biopsy in Endometrial Cancer--Comparison of 2 Detection Methods

OBJECTIVES

Sentinel lymph node biopsy (SLNB) can identify patients with nodal metastases who are eligible for tailored treatment. The aim of study was to compare the SLN detection rates using cervical and subserosal administration of 2 tracers.

RESULTS

In group 1 (82 patients), SLNB was performed using radiocolloid injected to the cervix and blue dye administered to the fundus. In group 2, blue dye was injected to cervix and fundus (106 patients). Only SLNB was performed in 128 (68.1%) women. In the remaining 60 (31.9%) patients, pelvic/para-aortic lymphadenectomy together with SLNB was performed. Groups 1 and 2 did not differ with regard to the frequencies of SLNB and lymphadenectomy. The detection rate for both groups was 90.9%. Bilateral detection was achieved in 72.5%. Para-aortic SLNs were found in 9.6%. Detection rates in groups 1 and 2 were 95.1% and 87.7% (P = 0.065). In comparison of cervical administration of radioisotope and subserosal injection of blue dye in group 1, we found a significant difference for total SLN detection (91.5% vs 74.4%, P < 0.05) and no significant difference for bilateral detection (73.3% vs 59.1%, P = 0.776). We did not find differences in the para-aortic SLN detection rates achieved after administration of a radiotracer and injection of a blue dye (4.9% vs 9.8%, P = 0.184). Eighteen patients (9.6%) presented with nodal disease, including 15 women with SLN involvement. The false-negative rate, calculated for patients subjected to lymphadenectomy, was 12.5% (1/8); using the SLNB surgical algorithm, it was 10% (1/10).

CONCLUSIONS

Cervical administration of a tracer, especially radioisotope, results in high SLN detection rates. In turn, the subserosal injection can be used only as an adjuvant method for SLNB. Low para-aortic SLN detection rates observed after cervical administration of a tracer do not seem to be a serious limitation of this technique.

Laparoscopic Indocyanine Green Sentinel Lymph Node Mapping in Endometrial Cancer

Background

In endometrial cancer (EMCA), indocyanine green (ICG) sentinel lymph node (SLN) mapping has been reported, mainly in conjunction with robotic surgery.

Objective

We aimed to evaluate detection rates, sensitivity, and false negative (FN) rate of laparoscopic ICG SLN mapping in EMCA, and to evaluate differences in surgical outcomes between patients subjected to SLN biopsy only versus lymphadenectomy.

Methods

A retrospective analysis of EMCA patients undergoing ICG SLN mapping ± pelvic (PLND) and/or para-aortic lymphadenectomy (PALND) was performed. Detection rates were calculated for the entire cohort. Sensitivity and FN rates were calculated for patients undergoing lymphadenectomy after SLN mapping, and surgical outcome was compared among patients undergoing SLN mapping only versus lymphadenectomy.

Results

Of 75 patients, 33 underwent SLN mapping and 42 underwent SLN mapping followed by PLND/PALND. Overall and bilateral detection rates were 96 % (72/75) and 88 % (66/75), respectively, and the median number of removed SLNs, pelvic non-SLNs (NSLN) and para-aortic NSLNs was 3, 27, and 19, respectively. With a FN rate of 8.3 %, only one patient had bilateral FN SLNs and a metastatic para-aortal NSLN. Estimated blood loss (EBL) and operative (OR) time were significantly lower in patients undergoing SLN mapping only. No differences in complication rates between patients undergoing SLN mapping only and patients undergoing lymphadenectomy were recorded.

Conclusions

Laparoscopic ICG SLN mapping has excellent overall and bilateral detection rates and a low FN rate. Compared with lymphadenectomy, SLN biopsy is associated with significantly lower EBL and shorter OR time.

The importance of para-aortic lymph nodes in sentinel lymph node mapping for endometrial cancer by using hysteroscopic radio-isotope tracer injection combined with subserosal dye injection: Prospective study

OBJECTIVE

The objective of this study is to evaluate the detection rate and diagnostic accuracy of sentinel lymph node (SN) mapping using hysteroscopic sub-endometrial injection of 99m-Technetium labeled phytate (Radio-isotope; RI method) and subserosal Indocyanine green (ICG) injection (Dye method) in patients with endometrial cancer.

METHODS

From April 2009 to December 2012, prospective evaluation of 57 Japanese endometrial cancer patients undergoing SN mapping using RI method combined with Dye method was done. To combine RI method or no was determined by a status of RI supply of the tracer injection day. As for 32 cases, both (RI+Dye) methods were used and 23 cases were performed only in Dye method. The primary endpoint was estimation of sensitivity and negative predictive value (NPV) of SN, and analysis of the distribution of SNs with metastasis.

RESULTS

At least one SN was detected in 100% and average number of detected SNs was 6.0 in RI+Dye method. Sensitivity and NPV were 100%, 100%, respectively. From results of SN mapping, 62.8% of SNs were present in pelvic and 37.1% in para-aortic lymph nodes (PAN). Total 56.3% of lymph nodes with metastasis were present in pelvic and 43.8% in PAN, and the distribution has no difference with SN mapping results (P=0.602). Among 13 cases with metastatic SNs, 76.9% cases showed metastasis in PAN.

CONCLUSIONS

This SN mapping procedure for endometrial cancer patients revealed high detection rate, sensitivity, NPV, and also indicated the importance of the SN exploration in PAN area.

Laparoscopic sentinel lymph node detection after hysteroscopic injection of technetium-99 in patients with endometrial cancer

BACKGROUND AND OBJECTIVES

Endometrial cancer (EC) has an increasing incidence worldwide. Despite the unequivocal prognostic importance of nodal status, systematic lymphadenectomy is associated to elevated morbidity. Sentinel lymph node (SLN) biopsy is designed to avoid extensive nodal dissection and provide crucial oncologic information. The goal of this prospective study was to determine the feasibility, safety, and accuracy of laparoscopic SLN biopsy in EC obtained through hysteroscopic injection of technetium-99 (Tc-99).

METHODS

From January 2008 to December 2012, a total of 42 women with EC were included in the study. We injected 20 mBq of Tc-99 hysteroscopically underneath the tumor minutes before definitive surgery. Thereafter, laparoscopic SLN identification /biopsy followed by pelvic and para-aortic lymphadenectomy, hysterectomy, and bilateral salpingo-oophorectomy were executed.

RESULTS

The total number of removed nodes was 970. The detection rate of the method was 73% (31/42). Among the 70 isolated SLNs, 35% (24) were exclusively identified in the para-aortic area. Fourteen patients (45%) had SLN only in the pelvic region, whereas 11 (35%) had SLN in both pelvic and para-aortic areas and 6 women (20%) had isolated para-aortic SNL. Nodal metastases were histologically confirmed in 9 patients (22%), and SLN was identified in 7 of 9 patients (78%). Although the obtained specificity was 100% and the negative predictive value was 89%, the sensitivity was only 58% (false-negative rate of 42%).

CONCLUSIONS

We could demonstrate that endoscopic SLN biopsy obtained through hysteroscopic injection of Tc-99 is a feasible and safe method. Despite the restricted number of included patients in this series, the obtained sensitivity and false-negative rates raise some questions about the real accuracy of the procedure in EC. Larger validation trials requiring quality pelvic and para-aortic lymphadenectomy are essential to correctly evaluate the method.

The Added Value of SPECT/CT in Sentinel Lymph Nodes Mapping for Endometrial Carcinoma

OBJECTIVES

This study was designed to evaluate the detection rate (DR) and sensitivity of sentinel lymph node (SLN) mapping in patients with endometrial cancer using TC99m colloid and blue dye and to evaluate the contribution of preoperative planar lymphoscintigraphy (PLSG) and SPECT/CT.

METHODS

A retrospective analysis of patients who underwent SLN mapping as part of their primary surgery for endometrial cancer. Patients underwent preoperative PLSG and later with additional SPECT/CT. Intraoperative detection was performed using TC99m colloid and blue dye by cervical injections. SLNs were sent separately for pathologic evaluation with ultrastaging.

RESULTS

Fifty-three patients were included in this study. Successful preoperative mapping was achieved in 31 of 37 patients (84 %) who underwent SPECT/CT compared with only 30 of 45 patients (67 %) who underwent PLSG. SPECT/CT localizations of SLNs were anatomically accurate in 91 % of cases. Intraoperative DR of at least one SLN was 77 %, whilst the bilateral DR was 49 %. DR was significantly better using combined blue dye and TC99m colloid injections compared with blue dye alone: 81 versus 57 % for unilateral and 54 versus 28 % for bilateral mapping (P = 0.01, 0.009, respectively). Six cases of nodal metastasis were diagnosed: four by positive SLNs, and two cases were diagnosed using side-specific full dissection according to the SLN algorithm when SLN detection failed. There were no cases of false-negative results.

CONCLUSIONS

SLN detection using cervical injections of TC99m colloid and blue dye is feasible and sensitive for patients with endometrial cancer. SPECT/CT aids to accurate locating of the SLN.

Factors associated with successful bilateral sentinel lymph node mapping in endometrial cancer

OBJECTIVE

As our understanding of sentinel lymph node (SLN) mapping for endometrial cancer (EC) evolves, tailoring the technique to individual patients at high risk for failed mapping may result in a higher rate of successful bilateral mapping (SBM). The study objective is to identify patient, tumor, and surgeon factors associated with successful SBM in patients with EC and complex atypical hyperplasia (CAH).

METHODS

From September 2012 to November 2014, women with EC or CAH underwent SLN mapping via cervical injection followed by robot-assisted total laparoscopic hysterectomy (RA-TLH) at a tertiary care academic center. Completion lymphadenectomy and ultrastaging were performed according to an institutional protocol. Patient demographics, tumor and surgeon/intraoperative variables were prospectively collected and analyzed. Univariate and multivariate analyses were performed evaluating factors known or hypothesized to impact the rate of successful lymphatic mapping.

RESULTS

RA-TLH and SLN mapping was performed in 111 women; 93 had EC and 18 had CAH. Eighty women had low grade and 31 had high grade disease. Overall, at least one SLN was identified in 85.6% of patients with SBM in 62.2% of patients. Dye choice (indocyanine green versus isosulfan blue), odds ratio (OR: 4.5), body mass index (OR: 0.95), and clinically enlarged lymph nodes (OR: 0.24) were associated with SBM rate on multivariate analyses. The use of indocyanine green dye was particularly beneficial in patients with a body mass index greater than 30.

CONCLUSION

Injection dye, BMI, and clinically enlarged lymph nodes are important considerations when performing sentinel lymph node mapping for EC.

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

OBJECTIVES

Sentinel lymph node (SLN) procedure could be an attractive solution to the debate on lymphadenectomy in endometrial cancer; however challenges to interpreting the literature include marked heterogeneity across studies, a wide variety of injection techniques and a lack of uniformly accepted definitions for important outcomes. We aim to critically appraise the published literature and streamline terminology and methodology for future studies in this field.

METHODS

We conducted a PubMed search and included all original research of endometrial cancer patients having undergone SLN procedure with an n>30. Data collected included injection technique, unilateral, bilateral, and para-aortic detection rates, and ultrastaging results. When different definitions were used for reporting outcomes, we recalculated the original study results according to our proposed definitions. Data was analyzed using descriptive statistics.

RESULTS

Seventeen studies met our inclusion criteria. Injection sites were categorized into cervical versus corporeal. Overall detection rates ranged from 60 to 100%; studies with n>100 all had overall detection rates of >80%. Bilateral detection rates were higher with a combination of two injection agents. Para-aortic mapping was most frequent after corporeal injection techniques (39%), and was higher after deep vs. standard cervical injection (17% vs. 2%). The proportion of metastatic lymph nodes diagnosed through ultrastaging was high (around 40%) and ultrastaging of SLN upstaged approximately 5% of patients. Retrospectively applying a surgical algorithm revealed a sensitivity of 95%, a negative predictive value of 99%, and a false negative rate of 5% (with only 9 false negative cases remaining in total).

CONCLUSION

Results of SLN research for endometrial cancer are promising. We believe that in future studies, uniform reporting is needed to improve our understanding of the safety and feasibility of SLN in EC. We propose 2 strategies: a checklist of elements to include in future reports and the standardization of key definitions.

Sentinel lymph node detection using 99mTc combined with methylene blue cervical injection for endometrial cancer surgical management: a prospective study

OBJECTIVE

The aim of this study is to evaluate the effectiveness of a combined technique for sentinel lymph node (SLN) localization and surgical staging of endometrial carcinoma.

METHODS

This is a single-center prospective observational study carried out from September 2011 to December 2013 including women with a diagnosis of endometrial cancer and scheduled for surgery. A regional lymph node mapping was obtained using SPECT-CT (cervical injection of Tc) the day before surgery. On the day of surgery, methylene blue was injected in the cervical tissue. The SLNs were identified intraoperatively guided both by a γ-probe and visual inspection of the blue dye. A pelvic and/or para-aortic lymphadenectomy was completed. A histological analysis was performed on all the removed lymph nodes. We calculated the detection rate for SLN and its negative predictive value (NPV) for malignancy.

RESULTS

Fifty patients underwent surgery. The SLN was isolated in 46 patients with detection rate of 92% (95% confidence interval, 80.77-97.78). The mean number of detected SLNs per patient was 1.54 (range, 1-5); the average number of non-SLNs removed was 17 (5-34) per patient. The most common SLN location was the external iliac lymph node chain, 33 (46.47%). Five SLNs (7.1%) were isolated in the para-aortic chain. Three SLN cases (5.9%) were positive for malignant cells; the totality of the remaining non-SLNs was negative. The NPV of the SLN was 100% (95% confidence interval, 89.79-99.79). Finally, pathologic findings were 42 endometrioid types (84%), 3 carcinosarcomas (6%), 4 clear cell (8%), and 1 serous papillary tumor (2%).

CONCLUSIONS

The SLN analysis may be useful to assess the presence or absence of lymph node metastases. Its high NPV may be used as criteria to avoid unnecessary lymphadenectomies in endometrial cancer patients.

Sentinel node mapping using hysteroscopic injection of indocyanine green and laparoscopic near-infrared fluorescence imaging in endometrial cancer staging

Herein is presented a technique for minimally invasive sentinel node mapping. The patient had apparently early stage endometrial cancer. Sentinel node mapping was performed using a hysteroscopic injection of indocyanine green followed by laparoscopic sentinel node detection via near-infrared fluorescence. This technique ensures delineation of lymphatic drainage from the tumor area, thus achieving accurate detection of sentinel nodes.

A comparison of colorimetric versus fluorometric sentinel lymph node mapping during robotic surgery for endometrial cancer

OBJECTIVE

The study objective was to compare the ability to detect sentinel lymph nodes (SLNs) in women with endometrial cancer (EC) or complex atypical hyperplasia (CAH) using fluorometric imaging with indocyanine green (ICG) versus colorimetric imaging with isosulfan blue (ISB).

METHODS

Women underwent SLN mapping, with either ISB or ICG, during robotic-assisted total laparoscopic hysterectomy (RA-TLH) from September 2012 to March 2014. SLNs were submitted for permanent pathologic analysis. Completion lymphadenectomy and ultrastaging were performed according to institutional protocols.

RESULTS

RA-TLH and SLN mapping was performed in 71 women; 64 had EC (64) and 7 had CAH. Age, body mass index (BMI), stage and tumor characteristics were similar in the ICG versus the ISB cohorts. Overall, SLNs were identified bilaterally (62.0%), unilaterally (21.1%), or neither (16.9%), and in 103 of 142 hemi-pelvises (72.5%). The mean number of SLNs retrieved per hemipelvis was 2.23(SD 1.7). SLNs were identified in the hypogastric (76.8%), external iliac (14.2%), common iliac (4.5%) and paraaortic (4.5%) regions. ICG mapped bilaterally in 78.9% of women compared with 42.4% of those injected with ISB (p=0.02). Five women (7%) had positive lymph nodes, all identified by the SLN protocol (false negative rate: 0%). On multivariate analysis, BMI was negatively correlated with bilateral mapping success (p=0.02). When stratified by dye type, the association with BMI was only significant for ISB (p=0.03).

CONCLUSIONS

Fluorescence imaging with ICG may be superior to colorimetric imaging with ISB in women undergoing SLN mapping for endometrial cancer. SLN mapping success is negatively associated with increasing patient BMI only when ISB is used.

Isthmocervical labelling and SPECT/CT for optimized sentinel detection in endometrial cancer: technique, experience and results

OBJECTIVE

We evaluated the clinical feasibility of a new injection technique for sentinel detection in endometrial carcinoma (EC), transcervical subepithelial injection into the isthmocervical region of the myometrium. We compared detection of sentinel lymph nodes (SLN) by single photon emission computed tomography with CT (SPECT/CT) with planar lymphoscintigraphy.

METHODS

This is a unicentric prospective study. In all patients, transcervical injection of 10 MBq Technetium-99m-nanocolloid was performed into the isthmocervical myometrium without anaesthesia. After 40 (30-60) min, lymphoscintigraphy and SPECT/CT were performed. Patent blue was administered before surgery. The number and localisation of SLN detected in SPECT/CT and lymphoscintigraphy were recorded and compared to the SLN and non-SLN dissected intra-operatively.

RESULTS

Between August 2008 and March 2012, 31 patients with EC were enrolled. The new transcervical injection of labelling substances led to high intra-operative (90.3%) detection rates, pelvic bilateral (57%), para-aortic (25%). SPECT/CT significantly identified more SLN than lymphoscintigraphy (mean 2.2 (1-8) to 1.3 (1-7)) in more patients (29/31 (93.5%) to 21/31 (68%), p<0.01). If SLN were identified in one hemi-pelvis, the histological evaluation of the SLN correctly predicted lymph node (LN) metastases for this basin which led to sensitivity 100%, negative predictive value (NPV) 100%, and false negative results 0%.

CONCLUSION

Transcervical SLN marking in combination with SPECT/CT is easily applicable and leads to high physiologic detection rates in pelvic and para-aortic lymphatic drainage areas. Non-affected SLN truly predicted a non-affected LN basin. Combining both methods SLN dissection may be a safe and feasible staging technique for clinical routine in EC.