A new approach to label sentinel nodes in endometrial cancer

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

Objective

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

Data sources

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

Research eligibility criteria

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

Study appraisal and synthesis methods

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

The results

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

Conclusions

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

Systematic review registration

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

Sentinel lymphatic mapping for gynecologic malignancies

PURPOSE OF REVIEW

To summarize the latest data in Gynecologic Oncology for the use of sentinel lymphatic mapping in vulvar, uterine, and cervical cancers.

RECENT FINDINGS

To decrease morbidity and improve detection of lymphatic metastasis, lymphatic mapping with sentinel lymph node biopsy is emerging as standard of care over conventional systemic lymphadenectomy in the surgical management of gynecologic malignancies.

SUMMARY

Sentinel lymph node mapping with biopsy is one of the most significant advances in cancer surgery. The presence of nodal metastasis is not only a prognostic factor for recurrence and survival in patients with gynecologic malignancies, but also guides assessment for adjuvant treatment. This review article discusses the most recent clinical updates in sentinel lymph node mapping, dissection, and management in vulvar cancer, endometrial cancer, and cervical cancer.

Feasibility of Sentinel Lymph Node Sampling in Early-Stage Carcinoma Endometrium: Single-Institution Experience

Introduction

Accurate surgical staging is an essential component in the management of carcinoma endometrium to assess the stage of disease and to tailor adjuvant treatment. Sentinel node technique was introduced as an alternative for extensive lymphadenectomy in early stages to avoid complications associated with lymphadenectomy.

Aims and Objectives

To assess the detection rate and diagnostic accuracy of SLN mapping in patients with early-stage carcinoma endometrium.

Materials and Methods

Prospective validation study involving 30 patients diagnosed to have early-stage carcinoma endometrium. Sentinel nodes were detected by combined methods of radio colloid dye and isosulphan blue dye injection.

Results

Sentinel lymph node was detected in 19 patients (63.4%). 11 patients had no sentinel nodes. Total number of sentinel nodes isolated was 68 with a mean of 2.26 per patient (range 0-4). Ten (33.33%) patients had single sentinel node location, while 9 (30%) had more than 1 sentinel lymph nodes. Twelve patients had bilateral sentinel nodes, and the most frequent location of sentinel node was obturator, 19 (63.3%) especially on right hemi-pelvis. One patient had a hot para-aortic node, while none had blue para-aortic sentinel node. Average number of lymph nodes obtained by lymphadenectomy was 13 per patient (range 7-22). All patients with sentinel node had negative frozen report as well as in histopathology. Two patients in whom no sentinel nodes were detected by either techniques had metastatic nodes in histopathology report.

Conclusion

Detection rate was maximum with radiocolloid dye, and it is better to utilize the technique for less graded tumours and endometrioid variants.

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.

Status of Sentinel Lymph Node Biopsy in Endometrial Cancer

The role of lymphadenectomy in surgical staging remains one of the biggest controversies in the management of endometrial cancer. The concept of sentinel lymph node biopsy in endometrial cancer has been evaluated for a number of years, with promising sensitivity rates and negative predictive values. The possibility of adequate staging while avoiding systematic lymphadenectomy leads to a significant reduction in the rate of peri- and postoperative morbidity. Nevertheless, the status of sentinel lymph node biopsy in endometrial cancer has not yet been fully elucidated and is variously assessed internationally. According to current European guidelines and recommendations, sentinel lymph node biopsy in endometrial cancer should be performed only in the context of clinical studies. In this review article, the developments of the past decade are explored concisely. In addition, current data regarding the technical aspects, accuracy and prognostic relevance of sentinel lymph node biopsy are explained and evaluated critically.

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.

A Comparison of Dye Versus Fluorescence Methods for Sentinel Lymph Node Mapping in Endometrial Cancer

OBJECTIVE

Sentinel nodes (SNs) have been observed in several reports from Japan and overseas in cases with endometrial cancer; however, no consensus has been reached regarding the types of tracers or the method of their injection. A combination of the radioisotope (RI) and dye method is considered to be desirable. We assessed SN mapping using either dye or near-infrared fluorescence imaging to clarify a suitable method in cases of endometrial cancer.

METHODS

Patients were enrolled from 92 patients diagnosed with endometrial cancer and having no extrauterine metastasis by the preoperative imaging between 2009 and 2014 at our institution. To identify the SNs, we performed 3 methods using either dye or fluorescence solutions in conjunction with a RI method. In the dye method, we injected indocyanine green in the uterine subserosa, visually identifying SNs as stained green. In the fluorescence method, a dilute indocyanine green solution (0.5 mg, fluorescence A or 0.25 mg, fluorescence B, each per 10 mL of solvent) was injected and the SN identified by the HyperEye Medical System.

RESULTS

The SN detection rates were 100%, 100%, and 96% using dye and fluorescence A or B solution, respectively. Pelvic SNs were detected by the 3 methods in 98%, 100%, and 96% of cases and para-aortic SNs in 65%, 88%, and 74%, respectively. Fluorescence A solution was somewhat better than dye in detecting para-aortic SNs, although not significantly so (P = 0.07). The sensitivity and negative predictive values for detecting SNs with metastases with the dye method were 92% and 98% compared with 100% and 100%, respectively, for both fluorescence solutions.

CONCLUSIONS

Although both dye and fluorescence methods performed well, no method perfectly identified para-aortic SNs. The concomitant use of the RI method is required to detect para-aortic SNs.

Predicting Model of Lymph Node Metastasis Using Preoperative Tumor Grade, Transvaginal Ultrasound, and Serum CA-125 Level in Patients With Endometrial Cancer

OBJECTIVE

The purpose of this study was to evaluate the predicting model for lymph node metastasis using preoperative tumor grade, transvaginal sonography (TVS), and serum cancer antigen 125 (CA-125) level in patients with endometrial cancer.

MATERIALS AND METHODS

Between January 2000 and February 2013, we identified 172 consecutive patients with surgically staged endometrial cancer. Transvaginal sonography was performed by an expert gynecologic radiologist in all patients. All patients had complete staging surgery including total hysterectomy with bilateral pelvic and para-aortic lymphadenectomy and were staged according to the 2009 International Federation of Gynecology and Obstetrics classification. Various clinicopathologic data were obtained from medical records and were retrospectively analyzed.

RESULTS

Of 172 patients, 138 patients presented with stage I (118 IA and 20 IB), 12 had stage II, 18 had stage III (2 IIIA, 1 IIIB, 8 IIIC1, and 7 IIIC2), and 2 had stage IV diseases. Most patients had endometrioid adenocarcinoma (88.4%), and others (12.6%) had nonendometrioid histology. Eighteen patients (10.5%) were found to have lymph node metastasis. Deep myometrial invasion on preoperative TVS (≥50%), high serum CA-125 level (≥ 35 IU/mL), preoperative grade 2 or 3 tumors were significant preoperative factors predicting lymph node metastasis. There was no significant association between preoperative histology and lymph node metastasis. We calculated the simple model predicting lymph node metastasis based on preoperative tumor grade, TVS findings, and CA-125 level using logistic regression analysis. The sensitivity and specificity of this model were 94% and 57%, respectively (area under the curve, 0.84; 95% confidence interval [CI], 0.74-0.93; P < 0.01).

CONCLUSIONS

Preoperative tumor grade, myometrial invasion on preoperative TVS, and CA-125 can accurately predict lymph node metastasis in patients with endometrial cancer. The current study suggests the possibility that TVS could be positively used for preoperative evaluation strategy in the low-resource countries instead of expensive imaging modalities such as magnetic resonance imaging or positron emission tomography-computed tomography.

Subserosal uterine injection of blue dye for the identification of the sentinel node in patients with endometrial cancer: a feasibility study

OBJECTIVE

To define the detection rate, sensitivity, and negative predictive value (NPV) of the sentinel node technique in patients with endometrial cancer.

METHODS

Patients with endometrial cancer after informed consent underwent subserosal injection of blue dye during hysterectomy in a tertiary gynae/oncology department between 2010 and 2014. The procedure was performed in all cases by the same team including two gynae/oncologist consultants and one trainee. All relevant perioperative clinicopathological characteristics of the population were recorded prospectively. The identified sentinel nodes were removed separately and a completion bilateral pelvic lymphadenectomy followed in all cases. Simple statistics were used to calculate the sensitivity and NPV of the method on per patient basis.

RESULTS

Fifty-four patients were included in this study. At least one sentinel node was mapped in 46 patients yielding a detection rate of 85.2%. Bilateral detection of sentinel nodes was accomplished in only 31 patients (57.4%). The mean number of sentinel nodes was 2.6 per patient and the commonest site of identification was the external iliac artery and vein area (66%). Six patients (11%) had a positive lymph node, and in five of them, this was the sentinel one yielding a sensitivity of 83.3% and an NPV of 97.5%. The overall detection rate improved significantly after the first 15 cases; however, this was not the case for the bilateral detection rate.

CONCLUSION

Our study is in accordance with previous studies of sentinel node in endometrial cancer and further demonstrates and enhances the confidence in the technique. In the current era of an ongoing debate on whether a systematic lymphadenectomy in patients with endometrial cancer is still necessary, we believe that the sentinel node is an acceptable alternative and should be applied routinely in tertiary centres following a strict algorithm.

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 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 Sentinel Node in Detecting Lymph Node Metastasis in Primary Endometrial Carcinoma

BACKGROUND

Endometrial carcinoma is the most common gynecological cancer and its treatment is still controversial, especially in its early stages. There are conflicting data about the efficacy of retroperitoneal lymphadenectomy during abdominal hysterectomy and bilateral salpingoophrectomy treatment. Lymphadenectomy carries a risk of severe complications, especially in women with co-morbidities. Selective lymphadenectomy has been widely employed for staging evaluation of endometrial carcinoma because it is simple and seems to provide reliable data regarding nodal metastasis. This study was designed to evaluate accuracy of sentinel node sampling in detecting lymph node metastasis in primary endometrial carcinoma during staging laparotomy.

MATERIALS AND METHODS

Ninety-three women with endometrial carcinoma at high-risk for nodal metastasis were studied. During laparotomy, methylene blue dye was injected into sub-serosal myometrium, then retroperitoneal spaces were opened and blue lymph nodes within pelvic and para-aortic regions were removed as separate specimens for histopathological examination (sentinel lymph nodes=SLNs). Hysterectomy and selective lymphadenectomy then performed for all women included in this study.

RESULTS

Deposition of methylene dye into at least one lymph node was observed in 73.1% (68/93) of studied cases. 18.3% (17/93) of studied women had positive lymph node metastasis and 94.1% (16/17) of them had positive metastasis in SLNs. In this study, SNLs had 94.4% sensitivity and 100% specificity in prediction of lymph node metastasis. Mean number of lymph nodes removed from each case decreased when SLNs biopsy were taken.

CONCLUSIONS

SLNs are the key lymph nodes in endometrial tumor metastasis and their involvement could be an indicator for whether or not complete systematic lymphadenectomy is needed during staging laparotomy.

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 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.

Uterine lymphangiography: comparison of two methods for locating the medial iliac lymph node

Different methods for lymphatic mapping in dogs, such as infusing tissues with vital dyes or radioactive substances, have been studied, aiming at the early detection of lymph node metastasis. Thus, one could anticipate therapeutic measures and, consequently, prolong the survival and improve the quality of life of the patients. The objectives of this experiment were to locate the nodes responsible for draining the uterine body and horns and to try to establish the relationship between the uterus and the medial iliac lymph nodes to contribute to the early diagnosis and prognosis of uterine disorders. We studied 15 female dogs divided into two groups (5 dead and 10 intraoperative ovariohysterectomy bitches). The dye used was patent blue V (Patent Bleu V®). It was observed that the iliac lymph node chain receives much of the uterine (horns) drainage. This method should be considered for safer studies of uterine sanity. This information suggests that evaluating these lymph nodes will allow correlating changes in their physiological status with uterine pathologies.

The EANM clinical and technical guidelines for lymphoscintigraphy and sentinel node localization in gynaecological cancers

The accurate harvesting of a sentinel node in gynaecological cancer (i.e. vaginal, vulvar, cervical, endometrial or ovarian cancer) includes a sequence of procedures with components from different medical specialities (nuclear medicine, radiology, surgical oncology and pathology). These guidelines are divided into sectione entitled: Purpose, Background information and definitions, Clinical indications and contraindications for SLN detection, Procedures (in the nuclear medicine department, in the surgical suite, and for radiation dosimetry), and Issues requiring further clarification. The guidelines were prepared for nuclear medicine physicians. The intention is to offer assistance in optimizing the diagnostic information that can currently be obtained from sentinel lymph node procedures. If specific recommendations given cannot be based on evidence from original scientific studies, referral is made to "general consensus" and similar expressions. The recommendations are designed to assist in the practice of referral to, and the performance, interpretation and reporting of all steps of the sentinel node procedure in the hope of setting state-of-the-art standards for high-quality evaluation of possible metastatic spread to the lymphatic system in gynaecological cancer. The final result has been discussed by a group of distinguished experts from the EANM Oncology Committee and the European Society of Gynaecological Oncology (ESGO). The document has been endorsed by the SNMMI Board.

Surgical treatment for apparent early stage endometrial cancer

Most experts would agree that the standard surgical treatment for endometrial cancer includes a hysterectomy and bilateral salpingo-oophorectomy; however, the benefit of full surgical staging with lymph node dissection in patients with apparent early stage disease remains a topic of debate. Recent prospective data and advances in laparoscopic techniques have transformed this disease into one that can be successfully managed with minimally invasive surgery. This review will discuss the current surgical management of apparent early stage endometrial cancer and some of the new techniques that are being incorporated.

Lymph node assessment in endometrial cancer: towards personalized medicine

Endometrial cancer (EC) is the most common malignancy of the female reproductive tract and is increasing in incidence. Lymphovascular invasion and lymph node (LN) status are strong predictive factors of recurrence. Therefore, the determination of the nodal status of patients is mandatory to optimally tailor adjuvant therapies and reduce local and distant recurrences. Imaging modalities do not yet allow accurate lymph node staging; thus pelvic and aortic lymphadenectomies remain standard staging procedures. The clinical data accumulated recently allow us to define low- and high-risk patients based on pre- or peroperative findings that will allow the clinician to stratify the patients for their need of lymphadenectomies. More recently, several groups have been introducing sentinel node mapping with promising results as an alternative to complete lymphadenectomy. Finally, the use of peroperative algorithm for risk determination could improve patient's staging with a reduction of lymphadenectomy-related morbidity.

Evaluation of the Sentinel Lymph Node Algorithm With Blue Dye Labeling for Early-Stage Endometrial Cancer in a Multicentric Setting

Objectives

Sentinel lymph node (SLN) removal may be a midterm between no and full pelvic dissection in early endometrial cancer. Whereas the use of blue dye alone in SLN detection has a poor accuracy, its integration in an SLN algorithm may yield better results and overcome hurdles such as the requirement of nuclear medicine facility.

Methods

Sixty-six patients with clinical stage I endometrial cancer were prospectively enrolled in a multicentre study between May 2003 and June 2009. Patent blue was injected intraoperatively into the cervix. We retrospectively assessed the accuracy of a previously described SLN algorithm consisting of the following sequence: (1) pelvic node area is inspected for removal of all mapped SLN and (2) excision of every suspicious non-SLN, (3) in the absence of mapping in a hemipelvis, a standard ipsilateral lymphadenectomy is then performed.

Results

Sentinel nodes were identified in 41 patients (62.1%), mostly in interiliac and obturator areas. None was detected in the para-aortic area. Detection was bilateral in 23 cases (56.1%). Seven patients (10.6%) had positive nodes. The false-negative rate was 40% using SLN detection alone. When the algorithm was applied, the false-negative rate was 14.3%. The use of a SLN algorithm would have avoided 53% of lymphadenectomies

Conclusion

Our multicentric evaluation validates the use of a SLN algorithm based on blue-only sentinel node mapping in early-stage endometrial cancer. The application of such SLN algorithm should be evaluated in a prospective context and might lead to decrease unnecessary lymphadenectomies.

Tracer injection sites and combinations for sentinel lymph node detection in patients with endometrial cancer

OBJECTIVE

The aim of the present study was to clarify the most effective combination of injected tracer types and injection sites in order to detect sentinel lymph nodes (SLNs) in early endometrial cancer.

PATIENTS AND METHODS

The study included 100 consecutive patients with endometrial cancer treated at Tohoku University Hospital between June 2001 and December 2012. The procedure for SLN identification entailed either radioisotope (RI) injection into the endometrium during hysteroscopy (55 cases) or direct RI injection into the uterine cervix (45 cases). A combination of blue dye injected into the uterine cervix or uterine body intraoperatively in addition to preoperative RI injection occurred in 69 of 100 cases. All detected SLNs were recorded according to the individual tracer and the resultant staging from this method was compared to the final pathology of lymph node metastases including para-aortic nodes.

RESULTS

SLN detection rate was highest (96%) by cervical RI injection; however, no SLNs were detected in para-aortic area. Para-aortic SLNs were detected only by hysteroscopic RI injection (56%). All cases with pelvic lymph node metastases were detected by pelvic SLN biopsy. Isolated positive para-aortic lymph nodes were detected in 3 patients. Bilateral SLN detection rate was high (96%; 26 of 27 cases) by cervical RI injection combined with dye.

CONCLUSION

RI injection into the uterine cervix is highly sensitive in detection of SLN metastasis in early stage endometrial cancer. It is a useful and safe modality when combined with blue dye injection into the uterine body.

Is sentinel lymph node dissection an appropriate standard of care for low-stage endometrial cancers? A review of the literature

BACKGROUND/AIMS

To review the literature and compare detection rates, false negative (FN) rates, and negative predictive values (NPVs) of sentinel lymph node (SLN) biopsy in endometrial cancer to those in breast and vulvar cancer. Secondary objectives were to evaluate techniques of SLN biopsy in endometrial cancer.

METHODS

The PubMed database was searched for applicable scientific articles. Detection rates, FN rates, and NPVs were calculated for all studies. Studies were stratified by techniques and compared.

RESULTS

Nineteen articles met criteria for this review. The overall detection rates ranged from 62 to 100%, the FN rate ranged from 0 to 50%, and the NPVs ranged from 95 to 100%. There is no technique that is definitively superior to any other with regard to surgical modality, injectant used, injection site, or pathologic techniques.

CONCLUSIONS

Studies on SLN biopsy in endometrial cancer have a large range of detection rates and FN rates, and larger studies including more patients with metastatic disease are needed for comparison with breast and vulvar cancers. While no techniques are definitively superior to others, minimally invasive surgery, cervical injection, and pathologic analysis utilizing HE staining, immunohistochemistry, and ultrastaging may be clinically advantageous.

Is it possible to predict para-aortic lymph node metastasis in endometrial cancer?

OBJECTIVE

The purpose of this study was to determine the histopathologic risk factors for pelvic lymph node (PLN) and para-aortic lymph node (PALN) metastasis in endometrial cancer (EC) and to identify in which patients PALN dissection should be performed.

STUDY DESIGN

A total of 204 consecutive patients, with EC and underwent systematic pelvic and para-aortic lymphadenectomy extending to the renal vessels, were studied retrospectively. Statistical significance between risk factors was examined using multivariant logistic regression analysis.

RESULTS

Cell type, depth of myometrial invasion and tumor size were found to be independently related to PLN metastasis. PLN metastasis in any site and lymphovascular invasion (LVSI) were independent prognostic factors for predicting PALN metastasis. The sensitivity, specificity and the NPV of PLN metastasis for detecting PALN metastasis were 80.8%, 89.3% and 97%, respectively. Furthermore, the 204 patients were divided into two groups according to the presence of one of these following factors: (1) non-endometrioid cell type, (2) PLN metastasis, (3) LVSI, (4) adnexal metastasis and (5) serosal involvement. Among these 204 patients, 104 had one or more of these factors (group A), and 100 patients had none of these factors (group B). PALN metastasis was significantly greater in group A, compared to group B. The sensitivity and the NPV of these combined prognostic factors for predicting PALN metastasis were 96.2% and 99%, respectively.

CONCLUSIONS

Presence of non-endometrioid cell type, PLN metastasis, LVSI, adnexal metastasis or serosal involvement diagnosed by frozen section (FS) seem to be poor prognostic factor for PALN metastasis in EC. Also, PALN dissection should be extended to the level of the renal vessels in all patients who will undergo PALN dissection, due to frequent involvement of the supramesenterial region.

[Current position of the sentinel lymph node procedure in endometrial cancer]

Lymph node status is a major prognostic element in endometrial cancer and affects the choice of adjuvant therapy. The sentinel lymph node (SLN) procedure is proposed as an alternative to lymphadenectomy. This review aims to assess its feasibility. To this end, 19 studies have been analysed. It appears that double detection (colorimetric and isotopic) is better than single detection, independent of injection site. Hysteroscopic injection is technically more difficult, yet can be done near the tumoral lesion. The cervical site does not accurately reflect the lymphatic drainage of the uterine body but is easier to access. SLN detection rate is notably identical between these two injections sites. Lomboaortic detection rate is lower for cervical injections than for endometrial ones. The myometrial site is also difficult to access (intraoperatively), due to same limitations as the hysteroscopic route, and can be deceiving (insufficient detection rate and high false-negative rate). The SLN allows for ultrastadification (micrometastases and isolated tumoral cells) with the development of new pathological techniques (serial sections and immunohistochemistry). Data on SLN in endometrial cancer is very heterogeneous in terms of methodology and populations studied. Despite being well-known, the SLN procedure in endometrial cancer remains in its feasibility stage. Its place in therapeutic strategies needs to be further explored and its potential benefit remains to be confirmed.

Detection rate and diagnostic accuracy of sentinel-node biopsy in early stage endometrial cancer: a prospective multicentre study (SENTI-ENDO)

BACKGROUND

Retrospective single-centre series have shown the feasibility of sentinel lymph-node (SLN) identification in endometrial cancer. We did a prospective, multicentre cohort study to assess the detection rate and diagnostic accuracy of the SLN procedure in predicting the pathological pelvic-node status in patients with early stage endometrial cancer.

METHODS

Patients with International Federation of Gynecology and Obstetrics (FIGO) stage I-II endometrial cancer had pelvic SLN assessment via cervical dual injection (with technetium and patent blue), and systematic pelvic-node dissection. All lymph nodes were histopathologically examined and SLNs were serial sectioned and examined by immunochemistry. The primary endpoint was estimation of the negative predictive value (NPV) of sentinel-node biopsy per hemipelvis. This is an ongoing study for which recruitment has ended. The study is registered with ClinicalTrials.gov, number NCT00987051.

FINDINGS

From July 5, 2007, to Aug 4, 2009, 133 patients were enrolled at nine centres in France. No complications occurred after injection of technetium colloid and no anaphylactic reactions were noted after patent blue injection. No surgical complications were reported during SLN biopsy, including procedures that involved conversion to open surgery. At least one SLN was detected in 111 of the 125 eligible patients. 19 of 111 (17%) had pelvic-lymph-node metastases. Five of 111 patients (5%) had an associated SLN in the para-aortic area. Considering the hemipelvis as the unit of analysis, NPV was 100% (95% CI 95-100) and sensitivity 100% (63-100). Considering the patient as the unit of analysis, three patients had false-negative results (two had metastatic nodes in the contralateral pelvic area and one in the para-aortic area), giving an NPV of 97% (95% CI 91-99) and sensitivity of 84% (62-95). All three of these patients had type 2 endometrial cancer. Immunohistochemistry and serial sectioning detected metastases undiagnosed by conventional histology in nine of 111 (8%) patients with detected SLNs, representing nine of the 19 patients (47%) with metastases. SLN biopsy upstaged 10% of patients with low-risk and 15% of those with intermediate-risk endometrial cancer.

INTERPRETATION

SLN biopsy with cervical dual labelling could be a trade-off between systematic lymphadenectomy and no dissection at all in patients with endometrial cancer of low or intermediate risk. Moreover, our study suggests that SLN biopsy could provide important data to tailor adjuvant therapy.

FUNDING

Direction Interrégionale de Recherche Clinique, Ile-de-France, Assistance Publique-Hôpitaux de Paris.

Does the use of the 2009 FIGO classification of endometrial cancer impact on indications of the sentinel node biopsy?

Background

Lymphadenectomy is debated in early stages endometrial cancer. Moreover, a new FIGO classification of endometrial cancer, merging stages IA and IB has been recently published. Therefore, the aims of the present study was to evaluate the relevance of the sentinel node (SN) procedure in women with endometrial cancer and to discuss whether the use of the 2009 FIGO classification could modify the indications for SN procedure.

Methods

Eighty-five patients with endometrial cancer underwent the SN procedure followed by pelvic lymphadenectomy. SNs were detected with a dual or single labelling method in 74 and 11 cases, respectively. All SNs were analysed by both H&E staining and immunohistochemistry. Presumed stage before surgery was assessed for all patients based on MR imaging features using the 1988 FIGO classification and the 2009 FIGO classification.

Results

An SN was detected in 88.2% of cases (75/85 women). Among the fourteen patients with lymph node metastases one-half were detected by serial sectioning and immunohistochemical analysis. There were no false negative case. Using the 1988 FIGO classification and the 2009 FIGO classification, the correlation between preoperative MRI staging and final histology was moderate with Kappa = 0.24 and Kappa = 0.45, respectively. None of the patients with grade 1 endometrioid carcinoma on biopsy and IA 2009 FIGO stage on MR imaging exhibited positive SN. In patients with grade 2-3 endometrioid carcinoma and stage IA on MR imaging, the rate of positive SN reached 16.6% with an incidence of micrometastases of 50%.

Conclusions

The present study suggests that sentinel node biopsy is an adequate technique to evaluate lymph node status. The use of the 2009 FIGO classification increases the accuracy of MR imaging to stage patients with early stages of endometrial cancer and contributes to clarify the indication of SN biopsy according to tumour grade and histological type.

Intraoperative sentinel lymph node detection by vital dye through laparoscopy or laparotomy in early endometrial cancer

BACKGROUND AND OBJECTIVES

Recent studies reported the feasibility of intraoperative lymphatic mapping in women with endometrial cancer but none of these studies compared the sentinel lymph nodes (SLNs) detection rates obtainable through laparoscopy or laparotomy. The purpose of this study was to address this issue.

METHODS

Thirty-four patients with clinical stage I-II endometrial cancer were enrolled in this prospective comparative trial. Four milliliters of Patent Blue Violet were injected into the cervix after the induction of general anesthesia. The assessment of SLNs was done in 17 patients through laparoscopy and in 17 patients through laparotomy as first step of systematic pelvic lymphadenectomy. Both SLNs and non-SLNs were evaluated for micrometastases.

RESULTS

The SLNs detection rate was significantly higher (82%) for laparoscopy than for laparotomy (41%; P = 0.008). Pelvic lymph node metastases were present in 6 out of 34 patients (18%) but only 3 (50%) of these patients were correctly identified.

CONCLUSIONS

SLNs detection rate is significantly higher through laparoscopy than through laparotomy after vital dye pericervical injection but intraoperative vital dye pericervical injection is not reliable as part of standard care for predicting lymphatic spread in women with early stage endometrial cancer.

Ultrastaging of lymph node in uterine cancers

Background

Lymph node status is an important prognostic factor and a criterion for adjuvant therapy in uterine cancers. While detection of micrometastases by ultrastaging techniques is correlated to prognosis in several other cancers, this remains a matter of debate for uterine cancers. The objective of this review on sentinel nodes (SN) in uterine cancers was to determine the contribution of ultrastaging to detect micrometastases.

Methods

Review of the English literature on SN procedure in cervical and endometrial cancers and histological techniques including hematoxylin and eosin (H&E) staining, serial sectioning, immunohistochemistry (IHC) and molecular techniques to detect micrometastases.

Results

In both cervical and endometrial cancers, H&E and IHC appeared insufficient to detect micrometastases. In cervical cancer, using H&E, serial sectioning and IHC, the rate of macrometastases varied between 7.1% and 36.3% with a mean value of 25.8%. The percentage of women with micrometastases ranged from 0% and 47.4% with a mean value of 28.3%. In endometrial cancer, the rate of macrometastases varied from 0% to 22%. Using H&E, serial sectioning and IHC, the rate of micrometastases varied from 0% to 15% with a mean value of 5.8%. In both cervical and endometrial cancers, data on the contribution of molecular techniques to detect micrometastases are insufficient to clarify their role in SN ultrastaging.

Conclusion

In uterine cancers, H&E, serial sectioning and IHC appears the best histological combined technique to detect micrometastases. Although accumulating data have proved the relation between the risk of recurrence and the presence of micrometastases, their clinical implications on indications for adjuvant therapy has to be clarified.

Endometrial cancer state of the science meeting

There is a pressing need to improve our understanding of endometrial cancer (EC) and uterine carcinosarcoma and to develop new treatment strategies to improve outcomes. In recognition of this, a State of the Science meeting on EC was held last November 28 and 29, 2006, in Manchester, United Kingdom. The meeting was cosponsored by the National Cancer Research Institute (UK), the National Cancer Institute (US), and the Gynecological Cancer Intergroup. The objectives of the meeting were as follows: 1. To review current knowledge and understanding of EC and its treatments. 2. To identify key issues for translational research and clinical trials. 3. To identify the most important trials for women with endometrial carcinoma and uterine carcinosarcoma, both those already underway or to be done, for which the Gynecological Cancer Intergroup might facilitate international cooperation.

Sentinel lymph node mapping for grade 1 endometrial cancer: is it the answer to the surgical staging dilemma?

OBJECTIVE

To describe the accuracy of SLN mapping in patients with a preoperative diagnosis of grade 1 endometrial cancer.

METHODS

A prospective, non-randomized study of women with a preoperative diagnosis of endometrial cancer and clinical stage I disease was conducted. A subset analysis of patients with a preoperative diagnosis of grade 1 endometrial endometrioid cancer was performed. All patients had preoperative lymphoscintigraphy with Tc99m on the day of or day before surgery followed by an intraoperative injection of 2 cm(3) of isosulfan or methylene blue dye deep into the cervix or both cervix and fundus. All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and regional nodal dissection. Hot and/or blue nodes were labeled as SLNs and sent for histopathological analysis.

RESULTS

Forty-two patients with a preoperative diagnosis of grade 1 endometrial carcinoma treated from 3/06 to 8/08 were identified. Twenty-five (60%) had laparoscopic surgery; 17 (40%) were treated by laparotomy. Preoperative lymphoscintigraphy visualized SLNs in 30 patients (71%); intraoperative localization of the SLN was possible in 36 patients (86%). A median of 3 SLNs (range, 1-14) and 14.5 non-SLNs (range, 4-55) were examined. In all, 4/36 (11%) had positive SLNs-3 seen on H&E and 1 as cytokeratin-positive cells on IHC. All node-positive cases were picked up by the SLN; there were no false-negative cases. The sensitivity of the SLN procedure in the 36 patients who had an SLN identified was 100%.

CONCLUSION

Sentinel lymph node mapping using a cervical injection with combined Tc and blue dye is feasible and accurate in patients with grade 1 endometrial cancer and may be a reasonable option for this select group of patients. Regional lymphadenectomy remains the gold standard in many practices, particularly for the approximately 15% of cases with failed SLN mapping.

Lymphatic Mapping in Endometrial Cancer: Comparison of Hysteroscopic and Subserosal Injection and the Distribution of Sentinel Lymph Nodes

Introduction:

Endometrial cancer incidence increases over the age of 65 and lymphadenectomy in these women is a morbid procedure. Sentinel lymph node (SLN) should avoid extensive lymphadenectomy in node negative patients. The aim of this prospective study is to determine the feasibility and usefulness of lymphatic mapping and SLN identification in the management of endometrial cancer.

Methods:

From January 2004 to December 2007 101 women with endometrial cancer participated in the study. We injected 99Tc hysteroscopically, peritumorally 2 hours before laparotomy in 24 women. We applied 99Tc and blue dye subserously after laparotomy and before adhesiolysis in 67 women. Ten patients with metastatic disease in ovary, omentum, peritoneum, and bulky nodes were excluded from analysis.

Results:

We detected SLN in 12 women (50%) in hysteroscopic group and in 49 women (73.1%) in subserous group. We identified 133 SLNs in 61 women. We found 20 SLNs (15.0%) in supraobturator region, 78 (58.6%) in external iliac area, 11 (8.3%) in paraaortal area, 13 (9.8%) on common iliac artery, 8 (6.0%) in medial part of lateral parametrium, and 3 (2.3%) in presacral area.

Conclusions:

Sentinel lymph node identification is a new strategy that can be used to examine nodal status with a high successful rate in breast, cervical, and vulvar cancer. Results in endometrial cancer are not as successful, however. In the future, it will be necessary to find optimal timing, the best route of application, and the "right" size of the 99mTc particles. Subserous application seems to be superior to hysteroscopic application.

Lymphatic mapping in endometrial cancer: a literature review of current techniques and results

The objective of this study was to review available literature pertaining to lymphatic mapping in endometrial cancer. We reviewed all published series of lymphatic mapping in endometrial cancer available through a PubMed search. Techniques used for identification of sentinel lymph nodes fell into three main categories in relation to the site of injection: 1) uterine subserosal, 2) cervical, and 3) endometrial via hysteroscopy. High detection rates may be achieved in all three categories. The use of both radiolabeled technetium and blue dye has been reported. A combination of cervical and uterine corpus injections appears feasible and less technically demanding than hysteroscopic injections. Immunohistochemistry staining of sentinel nodes coupled with step-serial section may improve the detection of micrometastasis in sentinel nodes. Meaningful sensitivity and false-negative rates cannot be calculated from current series due to their small numbers. The role of lymphatic mapping in endometrial carcinoma and the optimal injection site remains to be determined. A combination of cervical and uterine fundal injections may result in acceptable detection rates. Large-scale validation trials requiring complete pelvic and para-aortic lymphadenectomy are needed to evaluate its role in future clinical practice.

Techniques of sentinel lymph node identification for early-stage cervical and uterine cancer

Techniques for sentinel lymph node injections have varied over the years in both cervical and uterine malignancy lymph node mapping. There remains considerable variation in techniques, particularly for uterine malignancies. This review summarizes some of the techniques that have been published and are currently utilized in sentinel lymph node mapping for cervical and uterine malignancies.