Diagnostic value of frozen section examination of sentinel lymph nodes in early-stage cervical cancer at the time of ultrastaging

Sentinel lymph node pathological ultrastaging: Final outcome of the Sentix prospective international study in patients with early-stage cervical cancer

OBJECTIVE

To report the outcome of SLN staging in the SENTIX international prospective trial of SLN biopsy in patients with cervical cancer with an intensive ultrastaging protocol and central quality control and to evaluate how the intensity of pathological assessment correlates with metastatic detection rate in SLNs.

METHODS

Eligible were patients with stages T1a1/LVSI+ to T1b2 (<4 cm, ≤2 cm for fertility sparing), common tumor types, no suspicious lymph nodes on imaging, and bilateral SLN detection. SLNs were examined intraoperatively and processed by an intensive protocol for ultrastaging (paraffin blocks sectioned completely in 150-μm intervals/levels). SLNs from each site were submitted for central quality control.

RESULTS

In the SENTIX SLN study, 647 out of 733 enrolled patients underwent SLN ultrastaging, identifying 12.5% (81/647) with node positive, N1 cases. Intraoperative detection revealed metastases in 56.8% (46/81) of these cases, categorized into macrometastases (83.7%), micrometastases (26.3%), and isolated tumor cells (9.1%). Ultrastaging identified additional metastatic involvement in 43.2% (35/81) of patients, with detailed sectioning revealing metastases (MAC/MIC) at first level in 20 cases (24.7%), at levels 2-4 in 9 cases (11.1%), and at level ≥5 in 6 cases (7.4%).

CONCLUSION

SLN ultrastaging detects additional 43% of N1 (MAC/MIC) in patients with negative LNs by imaging and intraoperative pathological assessment. The detection rate of positive SLN correlates with the intensity (number of levels) of ultrastaging. Examination of four levels from paraffin blocks, which detects >90% of patients with N1, is a reasonable compromise for an international standard for ultrastaging.

STUDY REGISTRATION

NCT02494063 (ClinicalTrials.gov).

Benefits of sentinel node detection in cervical cancer

PURPOSE OF REVIEW

Sentinel lymph node biopsy (SLNB) is a widely used technique in other gynaecological tumours but has not yet been implemented as the gold standard technique for nodal staging in cervical cancer. Since the majority of evidence is derived from retrospective studies, this review aims to summarize the most recent evidence on this relevant topic.

RECENT FINDINGS

SLNB has demonstrated to be a well tolerated technique for lymph node staging in early-stage cervical cancer patients with promising future as exclusive lymph node assessment method avoiding full lymphadenectomy. Moreover, it allows ultrastaging and unfrequent drainage identification, which enables the detection of patients at a high risk of recurrence who would otherwise remain unnoticed. When compared with pelvic lymphadenectomy, SLNB is also associated with less intraoperative and postoperative complications, especially in terms of lymphedema formation.

SUMMARY

The available evidence suggests that SLNB offers numerous advantages over the standard pelvic lymphadenectomy reducing morbidity rates and increasing diagnostic accuracy. Three ongoing prospective trials will likely answer the controversies over these questions.

Survival associated with the use of one-step nucleic acid amplification (OSNA) to detect sentinel lymph node metastasis in cervical cancer

INTRODUCTION

Sentinel lymph node (SLN) biopsy is part of surgical treatment of apparent early-stage cervical cancer. SLN is routinely analyzed by ultrastaging and immunohistochemistry. The aim of this study was to assess the survival of patients undergoing SLN analyzed by one-step nucleic acid amplification (OSNA) compared with ultrastaging.

METHODS

Single-center, retrospective, cohort study. Patients undergoing primary surgery and SLN mapping ( ±pelvic lymphadenectomy) for apparent early-stage cervical cancer between May 2017 and January 2021 were included. SLN was analyzed exclusively with OSNA or with ultrastaging. Patients with bilateral SLN mapping failure, with SLN analyzed alternatively/serially with OSNA and ultrastaging, and undergoing neo-adjuvant therapy were excluded. Baseline clinic-pathological differences between the two groups were balanced with propensity-match analysis.

RESULTS

One-hundred and fifty-seven patients were included, 50 (31.8%) in the OSNA group and 107 (68.2%) in the ultrastaging group. Median follow up time was 41 months (95%CI:37.9-42.2). 5-year DFS in patients undergoing OSNA versus ultrastaging was 87.0% versus 91.0% (p = 0.809) and 5-year overall survival was 97.9% versus 98.6% (p = 0.631), respectively. No difference in the incidence of lymph node recurrence between the two groups was noted (OSNA 20.0% versus ultrastaging 18.2%, p = 0.931). In the group of negative SLN, no 5-year DFS difference was noted between the two groups (p = 0.692). No 5-year DFS and OS difference was noted after propensity-match analysis (87.6% versus 87.0%, p = 0.726 and 97.4% versus 97.9%, p = 0.998, respectively).

CONCLUSION

The use of OSNA as method to exclusively process SLN in cervical cancer was not associated with worse DFS compared to ultrastaging. Incidence of lymph node recurrence in the two groups was not different.

Steerable DROP-IN radioguidance during minimal-invasive non-robotic cervical and endometrial sentinel lymph node surgery

PURPOSE

The recently introduced tethered DROP-IN gamma probe has revolutionized the way robotic radioguided surgery is performed, fully exploiting the nature of steerable robotic instruments. Given this success, the current first-in-human study investigates if the DROP-IN can also provide benefit in combination with steerable non-robotic instruments during conventional laparoscopic surgery, showing equivalence or even benefit over a traditional rigid gamma probe.

METHODS

The evaluation was performed in ten patients during laparoscopic cervical (n = 4) and endometrial (n = 6) cancer sentinel lymph node (SLN) procedures. Surgical guidance was provided using the hybrid, or bi-modal, SLN tracer ICG-99mTc-nanocolloid. SLN detection was compared between the traditional rigid laparoscopic gamma probe, the combination of a DROP-IN gamma probe and a steerable laparoscopic instrument (LaproFlex), and fluorescence imaging.

RESULTS

The gynecologists experienced an enlarged freedom of movement when using the DROP-IN + LaproFlex combination compared to the rigid laparoscopic probe, making it possible to better isolate the SLN signal from background signals. This did not translate into a change in the SLN find rate yet. In both cervical and endometrial cancer combined, the rigid probe and DROP-IN + LaproFlex combination provided an equivalent detection rate of 96%, while fluorescence provided 85%.

CONCLUSION

We have successfully demonstrated the in-human use of steerable DROP-IN radioguidance during laparoscopic cervical and endometrial cancer SLN procedures, expanding the utility beyond robotic procedures. Indicating an improved surgical experience, these findings encourage further investigation and consideration on a path towards routine clinical practice and improved patient outcome.

TRIAL REGISTRATION

HCB/2021/0777 and NCT04492995; https://clinicaltrials.gov/study/NCT04492995.

Precisional detection of lymph node metastasis using tFCM in colorectal cancer

The detection of colorectal cancer (CRC) lymph node (LN) metastases significantly influences treatment choices, yet identifying them in samples is time-consuming and error-prone. To enhance efficiency, we have established a LN metastasis detection method utilizing triple-parameter flow cytometry (tFCM) and have conducted a comparative assessment of its accuracy and cost-effectiveness in contrast to conventional pathological examinations. This technique utilized biomarkers cytokeratin 20 (CK20), epithelial cell adhesion molecules (EpCAM), and Pan-CK. tFCM's sensitivity was validated by analyzing known cell line concentrations (SW480 and SW620) in peripheral blood mononuclear cells (PBMCs), with CK20, EpCAM, and Pan-CK showing significant expression in CRC cell lines but not in PBMCs. A strong linear correlation was observed in the mixed leukocyte environment (R 2 = 0.9988). Subsequently, tFCM and pathological sections were employed to analyze LNs from CRC patients, enabling comparison of detection accuracy. Within the 36 LNs studied, tFCM successfully identified tumor cells with varying metastasis degrees, including micro-metastasis and isolated tumor cell clusters. Notably, relying solely on pathological sections led to a potential 25% misdiagnosis rate for LNs. In contrast, tFCM effectively minimized this risk. In summary, compared to traditional pathological sections, tFCM is a more advantageous method for detecting nodal metastasis in CRC patients, offering a more precise prognosis for these patients.

Diagnostic accuracy of sentinel lymph node frozen section analysis in patients with early-stage cervical cancer: A systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of intraoperative SLN frozen section analysis compared with ultrastaging in patients with early-stage cervical cancer.

METHODS

A systematic literature review was conducted following the PRISMA checklist. MEDLINE (via Ovid), Embase, and the Cochrane Central Register of Controlled Trials were searched from inception until February 2023. The inclusion criteria were patients with early-stage cervical cancer (2018 FIGO stage I-II), consisting of the histological subtype squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma (≥90% of the patients in each study), who underwent SLN detection (with any tracer) and intraoperative frozen section followed by SLN ultrastaging. Randomized controlled trials, prospective and retrospective observational studies were considered. The detection rates and measures of diagnostic accuracy were pooled using a random effects univariate model. A preplanned subgroup meta-analysis was conducted, with isolated tumor cells excluded as positive lymph nodes. The review was registered in PROSPERO (CRD42023397147).

RESULTS

The search identified 190 articles, with 153 studies considered potentially eligible after removing duplicates. Fourteen studies met the selection criteria, including a total of 1720 patients. Seven studies were retrospective, and the other seven were prospective. Frozen section analysis detected 159 of 292 (54.5%) patients with lymph node metastases. In 281 patients the type of volume metastasis was reported: 1 of 41 (2.4%) patients had isolated tumor cells, 21 of 78 (26.9%) patients had micrometastases, and 133 of 162 (82.1%) patients had macrometastases. The pooled sensitivity of intraoperative SLN frozen section analysis was 65% (95% CI, 51-77%) for macrometastases, micrometastases, and isolated tumor cells. When we excluded patients with isolated tumor cells, the pooled sensitivity increased to 72% (95% CI, 60-82%).

CONCLUSION

SLN frozen section detects 65% of lymph node metastases compared with SLN ultrastaging and may prevent unnecessary radical surgery in some patients with early-stage cervical cancer.

Predictors of Non-Sentinel Lymph Node Metastasis in Patients with Positive Sentinel Lymph Node in Early-Stage Cervical Cancer: A SENTICOL GROUP Study

BACKGROUND

The goal of this study was to identify the risk factors for metastasis in the remaining non-sentinel lymph nodes (SLN) in the case of positive SLN in early-stage cervical cancer.

METHODS

An ancillary analysis of two prospective multicentric databases on SLN biopsy for cervical cancer (SENTICOL I and II) was performed. Patients with early-stage cervical cancer (FIGO 2018 IA to IIA1), with bilateral SLN detection and at least one positive SLN after ultrastaging, were included.

RESULTS

405 patients were included in SENTICOL I and Il. Fifty-two patients had bilateral SLN detection and were found to have SLN metastasis. After pelvic lymphadenectomy, metastatic involvement of non-SLN was diagnosed in 7 patients (13.5%). Patients with metastatic non-SLN were older (51.9 vs. 40.8 years, p = 0.01), had more often lympho-vascular space invasion (LVSI) (85.7% vs. 35.6%, p = 0.03), and had more often parametrial involvement (42.9% vs. 6.7%, p = 0.003). Multivariate analysis retained age (OR = 1.16, 95% IC = [1.01-1.32], p = 0.03) and LVSI (OR = 25.97, 95% IC = [1.16-582.1], p = 0.04) as independently associated with non-SLN involvement.

CONCLUSIONS

Age and LVSI seemed to be predictive of non-SLN metastasis in patients with SLN metastasis in early-stage cervical cancer. Larger cohorts are needed to confirm the results and clinical usefulness of such findings.

The distribution pattern of pelvic lymph nodal metastases in cervical cancer

PURPOSE

Depiction of pelvic lymph node metastasis (LNM) sites among patients with cervical cancer facilitates accurate determination of the extent of dissection and radiotherapy regimens.

METHODS

A retrospective study of 1182 cervical cancer patients who underwent radical hysterectomy and pelvic lymph node dissection between 2008 and 2018 was performed. The number of removed pelvic lymph nodes and metastasis status in different anatomical regions was analyzed. The prognostic difference of patients with lymph node involvement stratified by various factors was analyzed by Kaplan-Meier method.

RESULTS

The median number of pelvic lymph nodes detected was 22, mainly from obturator (29.54%) and inguinal (21.14%) sites. Metastatic pelvic lymph nodes were found in 192 patients, with obturator accounting for the highest percentage (42.86%). The patients with lymph node involvement in single site had better prognosis that those in multiple sites. The overall- (P = 0.021) (OS) and progression-free (P < 0.001) survival (PFS) curves of patients with inguinal lymph node metastases were worse compared to those with obturator site. There was no difference in the OS and PFS among patients with 2 and more than 2 lymph nodes involvement.

CONCLUSION

An explicit map of LNM in patients with cervical cancer was presented in this study. Obturator lymph nodes tended to be involved. The prognosis of patients with inguinal lymph node involvement was poor in contrast to that with obturator LNM. In patients with inguinal lymph node metastases, clinical staging needs to be reconsidered and extended radiotherapy to the inguinal region needs to be strengthened.

Sentinel Lymph Node Biopsy in Uterine Cancer: Time for a Modern Approach

Since the validation of the sentinel node technique (SLN) for vulvar cancer 20 years ago, this technique has been introduced in the management of operable cervical cancer and endometrial cancer. For cervical cancer a "one fits all" attitude has mainly been presented. However, this approach, consisting of a frozen section during the operation, can be discussed in some stages. We present and discuss the main option for each stage, as well as some secondary possibilities. For endometrial cancer, SLN is now the technique of choice for the nodal staging of low- and intermediate-risk groups. Some discussion exists for the high-risk group. We also discuss the impacts of using preoperatively the molecular classification of endometrial cancer. Patients with POLE or TP53 mutations could have different nodal staging. The story of SLN in uterine cancers is not finished. We propose a comprehensive algorithm of SLN in early cervical and endometrial cancers. However, several ongoing trials will give us important data in the coming years. They could substantially change these propositions.

Dataset for the Reporting of Carcinoma of the Cervix: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

Cervical carcinoma remains one of the most common cancers affecting women worldwide, despite effective screening programs being implemented in many countries for several decades. The International Collaboration on Cancer Reporting (ICCR) dataset for cervical carcinoma was first developed in 2017 with the aim of developing evidence-based standardized, consistent and comprehensive surgical pathology reports for resection specimens. This 4th edition update to the ICCR dataset on cervical cancer was undertaken to incorporate major changes based upon the updated International Federation of Obstetricians and Gynecologists (FIGO) staging for carcinoma of the cervix published in 2018 and the 5th Edition World Health Organization (WHO) Classification of Female Genital Tumors published in 2020 and other significant developments in pathologic aspects of cervical cancer. This updated dataset was developed by a panel of expert gynecological pathologists and an expert gynecological oncologist, with a period of open consultation. The revised dataset includes "core" and "noncore" elements to be reported; these are accompanied by detailed explanatory notes and references providing the rationale for the updates. Standardized reporting using datasets such as this helps facilitate consistency and accuracy, data collection across different sites and comparison of epidemiological and pathologic parameters for quality and research purposes.

Estimation risk of lymph nodal invasion in patients with early-stage cervical cancer: Cervical cancer application

Introduction

Lymph node status is a major prognostic factor in early-stage cervical cancer. Predicting the risk of lymph node metastasis is essential for optimal therapeutic management. The aim of the study was to develop a web-based application to predict the risk of lymph node metastasis in patients with early-stage (IA1 with positive lymph vascular space invasion, IA2 and IB1) cervical cancer.

Materials and methods

We performed a secondary analysis of data from two prospective multicenter trials, Senticol 1 and 2 pooled together in the training dataset. The histological risk factors were included in a multivariate logistic regression model in order to determine the most suitable prediction model. An internal validation of the chosen prediction model was then carried out by a cross validation of the ‘leave one out cross validation’ type. The prediction model was implemented in an interactive online application of the ‘Shinyapp’ type. Finally, an external validation was performed with a retrospective cohort from L’Hôtel-Dieu de Québec in Canada.

Results

Three hundred twenty-one patients participating in Senticol 1 and 2 were included in our training analysis. Among these patients, 280 did not present lymph node invasion (87.2%), 13 presented isolated tumor cells (4%), 11 presented micrometastases (3.4%) and 17 macrometastases (5.3%). Tumor size, presence of lymph-vascular space invasion and stromal invasion were included in the prediction model. The Receiver Operating Characteristic (ROC) Curve from this model had an area under the curve (AUC) of 0.79 (95% CI [0.69– 0.90]). The AUC from the cross validation was 0.65. The external validation on the Canadian cohort confirmed a good discrimination of the model with an AUC of 0.83.

Discussion

This is the first study of a prediction score for lymph node involvement in early-stage cervical cancer that includes internal and external validation. The web application is a simple, practical, and modern method of using this prediction score to assist in clinical management.

Sentinel Lymph Node Mapping: Current Applications and Future Perspectives in Gynecology Malignant Tumors

The sentinel lymph nodes (SLNs) is a group of lymph nodes initially involved in the metastatic spread of cancer cells. SLN mapping refers to intraoperative localization and biopsy of SLNs with specific tracers to assess lymph node metastases. It is widely used in a variety of tumor surgeries for its high sensitivity and high negative predictive value. In the evaluation of the status of lymph node metastases in gynecological malignancies, it has received increasingly more attention due to its minor invasiveness, few complications, and high diagnosis rate. The National Comprehensive Cancer Network (NCCN) guidelines provide an excellent introduction to the indications and methods of SLN techniques in vulvar, cervical, and endometrial cancers, but they provide little explanation about some specific issues. In this review, we summarize different dyes and injection methods and discuss the indications of application and the clinical trials of SLN mapping in gynecological malignant tumors, aiming to provide a reference for the rational application of sentinel techniques in gynecology malignant tumors before relevant guidelines are updated.

Clinical impact of low-volume lymph node metastases in early-stage cervical cancer: A comprehensive meta-analysis

OBJECTIVE

In order to define the clinical significance of low-volume metastasis, a comprehensive meta-analysis of published data and individual data obtained from articles mentioning micrometastases (MIC) and isolated tumor cells (ITC) in cervical cancer was performed, with a follow up of at least 3 years.

METHODS

We performed a systematic literature review and meta-analysis, following Cochrane's review methods guide and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcome was the disease-free survival (DFS), and the secondary outcome was the overall survival (OS). The hazard ratio (HR) was taken as the measure of the association between the low-volume metastases (MIC+ITC and MIC alone) and DFS or OS; it quantified the hazard of an event in the MIC (+/- ITC) group compared to the hazard in node-negative (N0) patients. A random-effect meta-analysis model using the inverse variance method was selected for pooling. Forest plots were used to display the HRs and risk differences within individual trials and overall.

RESULTS

Eleven articles were finally retained for the meta-analysis. In the analysis of DFS in patients with low-volume metastasis (MIC + ITC), the HR was increased to 2.60 (1.55-4.34) in the case of low-volume metastasis vs. N0. The presence of MICs had a negative prognostic impact, with an HR of 4.10 (2.71-6.20) compared to N0. Moreover, this impact was worse than that of MIC pooled with ITCs. Concerning OS, the meta-analysis shows an HR of 5.65 (2.81-11.39) in the case of low-volume metastases vs. N0. The presence of MICs alone had a negative effect, with an HR of 6.94 (2.56-18.81).

CONCLUSIONS

In conclusion, the presence of MIC seems to be associated with a negative impact on both the DFS and OS and should be treated as MAC.

The accuracy of intraoperative frozen section examination of sentinel lymph nodes in squamous cell cancer of the vulva

OBJECTIVE

To assess the diagnostic accuracy of intraoperative pathologic examination of sentinel lymph nodes (SLNs) and patient outcomes in vulva cancer.

METHODS

This retrospective study included patients with unifocal, <4 cm, invasive vulvar squamous cell carcinoma and clinically negative groin nodes treated with SLN biopsy from January 2008-March 2020. Intraoperative SLN frozen section and final pathology were compared. If the SLN was negative, inguinal femoral lymphadenectomy (IFLD) was omitted. Recurrence location and groin recurrence free survival (RFS) were assessed.

RESULTS

The SLN cohort included 173 patients, with 258 groins. On frozen section, there were 36/258 positive and 222 negative groins. On final pathology, there were 39/258 positive: 31 macrometastases, 6 micrometastases, 2 isolated tumor cells (ITCs) and 219 negative groins. The sensitivity, specificity, PPV and NPV for intraoperative detection of metastatic disease, was 89.7% and 99.5%, 97.2% and 98.2%, respectively. There was 1 false positive and 4 false negative frozen section results where final pathology revealed 2 ITCs, 1 micrometastasis and 1 macrometastasis. Based on intraoperative results, thirty patients (17.3%) underwent immediate IFLD. Median follow up was 38.0 (1-137.8) months. The 3-year groin RFS was 91.6% (95% CI 86.2-97.4%) for negative SLNs and 64.6% (95% CI 46.5-89.7%) for positive SLNs on frozen section. Similarly, the 3-year groin RFS was 91.7% (95% CI 86.3-97.4%) for negative, 58.4% (95% CI 38.5-87.7%) for macrometastases and 100% for micrometastases/ITCs on final pathology.

CONCLUSIONS

Intraoperative assessment of SLNs is accurate to determine need for IFLD and does not compromise patient outcomes in vulvar cancer.

Can Conization Specimens Predict Sentinel Lymph Node Status in Early-Stage Cervical Cancer? A SENTICOL Group Study

Simple Summary

Lymph node involvement is one of the major prognosis factors for early-stage cervical cancer. Improvement in preoperative identification of node-positive patients may lead to a more accurate triage to primary chemoradiation for these patients instead of radical surgery followed by adjuvant radiotherapy, given the increased morbidity of combined treatment. Several studies have well established risk factors for node involvement, but they are based on final pathologic examination of radical hysterectomy specimens and are usually extrapolated for preoperative risk assessment. Among these risk factors, tumor size, lymphovascular space invasion (LVSI) and depth of stromal invasion might be assessed in conization specimens. Our findings suggest that patients with depth of stromal invasion lower than 10 mm and no LVSI in conization specimens had lower risk of micro- and macrometastatic SLN. In this subpopulation, full node dissection may be questionable in case of SLN unilateral detection.

Abstract

Background: The prognosis of patients with cervical cancer is significantly worsened in case of lymph node involvement. The goal of this study was to determine whether pathologic features in conization specimens can predict the sentinel lymph node (SLN) status in early-stage cervical cancer. Methods: An ancillary analysis of two prospective multicentric database on SLN biopsy for cervical cancer (SENTICOL I and II) was carried out. Patients with IA to IB2 2018 FIGO stage, who underwent preoperative conization before SLN biopsy were included. Results: Between January 2005 and July 2012, 161 patients from 25 French centers fulfilled the inclusion criteria. Macrometastases, micrometastases and Isolated tumor cells (ITCs) were found in 4 (2.5%), 6 (3.7%) and 5 (3.1%) patients respectively. Compared to negative SLN patients, patients with micrometastatic and macrometastatic SLN were more likely to have lymphovascular space invasion (LVSI) (60% vs. 29.5%, p = 0.04) and deep stromal invasion (DSI) ≥ 10 mm (50% vs. 17.8%, p = 0.04). Among the 93 patients with DSI < 10 mm and absence of LVSI on conization specimens, three patients (3.2%) had ITCs and only one (1.1%) had micrometastases. Conclusions: Patients with DSI < 10 mm and no LVSI in conization specimens had lower risk of micro- and macrometastatic SLN. In this subpopulation, full node dissection may be questionable in case of SLN unilateral detection.

Status of Sentinel Lymph Node Biopsy in Vulvar and Cervical Cancer

Assessment of lymphatic metastasis is an essential component of solid tumour staging. Sentinel lymph node (SLN) biopsy is a minimally invasive procedure that allows regional lymph node involvement by tumour to be estimated by selectively examining the sentinel lymph node while minimising the morbidity of systematic lymph node dissection. Within the group of genital cancers, the diagnostic value of SLN biopsy is rated differently. For selected patients with early-stage vulvar cancer (unifocal primary tumour < 4 cm, clinically negative inguinal lymph nodes) the SLN technique is already an established procedure in the guidelines of the German Society for Gynaecology and Obstetrics (DGGG)/German Cancer Society (DKG) and the recommendations of the European Society of Gynaecological Oncology (ESGO). For cervical cancer, SLN biopsy has not yet been sufficiently standardised but can be considered for patients without risk factors with a primary tumour size < 2 cm. The SLN is identified by combined use of radioactive ^99m technetium nanocolloid and patent blue. The use of indocyanine green offers an alternative for SLN identification with few side effects. Recent studies aim to increase the diagnostic reliability of intraoperative frozen section analysis as this continues to show limited sensitivity in both vulvar and cervical cancer. The rate of detection of micrometastases can be increased by additional ultrastaging, the prognostic significance of which for both diseases is still unclear. The prognostic value of SLN biopsy compared with systematic lymph node dissection is being investigated in current studies (GROINSS-V-II for vulvar cancer and SENTIX-, SENTICOL-3 for cervical cancer). For this review article, a guideline-based literature search was performed in the National Library of Medicine (PubMed/MEDLINE) database with a particular focus on recent cohort studies and conference contributions.