Assessment of the sentinel lymph node in patients with invasive squamous carcinoma of the vulva

Should video laryngoscopy or direct laryngoscopy be used for adults undergoing endotracheal intubation in the pre-hospital setting? A critical appraisal of a systematic review

The safety and utility of endotracheal intubation by paramedics in the United Kingdom is a matter of debate. Considering the controversy surrounding the safety of paramedic-performed endotracheal intubation, any interventions that enhance patient safety should be evaluated for implementation based on solid evidence of their effectiveness. A systematic review performed by Hansel and colleagues (2022) sought to assess compare video laryngoscopes against direct laryngoscopes in clinical practice. This commentary aims to critically appraise the methods used within the review by Hansel et al (2022) and expand upon the findings in the context of clinical practice.

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.

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.

Gynaecological malignancies and sentinel lymph node mapping: an update

Assessment of pelvic, para-aortic or inguinal lymph nodes (LNs) provides not only important prognostic information, but also determines the need for adjuvant treatment. Sentinel lymph node (SLN) biopsy has the potential to provide this prognostic information, while reducing morbidity compared with extended LN dissection. This review discusses the clinical and pathological aspects of SLN biopsy in gynaecological cancer.

Feasibility of internal inguinoperitoneal drainage after inguinofemoral lymphadenectomy in vulvar cancer

PURPOSE

Despite the introduction of sentinel node biopsy in patients with vulvar cancer, still approximately 50% of all patients have to undergo an inguinofemoral lymphadenectomy. This is associated with a high incidence of postoperative complications, which may be influenced by inguinal drain management. The aim of this study was to investigate the feasibility of a new surgical technique regarding drain management with an inguinoperitoneal drainage.

METHODS

A retrospective analysis of 21 vulvar cancer patients with inguinofemoral lymphadenectomy was conducted. A silicone drain was circularly placed with the perforated end in the groin and the other end in the space of Douglas. The removal after 3 months was performed under local anesthesia. All patients were questioned during clinical follow-up regarding their personal experiences with the procedure, the occurrence of complications, and side effects using a clinical questionnaire.

RESULTS

In 100% of the patients, the procedure was feasible. Regarding the number of groin punctures due to lymphocyst formation, 15 (71.4%) patients did not need any intervention and 3 (14.3%) patients needed 1-3 punctures. The patient satisfaction with the internal drainage was ranked as good by 17 (81.0%) patients and as moderate by 1 (4.8%) patient. In 3 (14.3%) patients, information about the number of groin punctures and the patient satisfaction were missing.

CONCLUSION

Inguinoperitoneal drainage after inguinofemoral lymphadenectomy in vulvar cancer patients is feasible and safe and a patient satisfaction of 81% is promising. For definitive conclusions regarding the efficacy of this technique, further investigations and prospective multicenter trials are needed.

Pathology of sentinel lymph nodes: historical perspective and current applications in gynecologic cancer

Efforts to reduce surgical morbidity related to en bloc lymph node removal associated with cancer surgery led to the development of targeted lymph node sampling to identify the lymph node(s) most likely to harbor a metastasis. Through identification of one or only a few lymph nodes at highest risk, the overall number of lymph nodes removed could be markedly reduced. Submission of fewer lymph nodes affords more detailed pathologic examination than would otherwise be practical with a standard lymph node dissection. Such enhanced pathologic examination techniques (ie, ultra-staging) have contributed to increased detection of lymph node metastases, primarily by detection of low volume metastatic disease. Based on the success of sentinel lymph node mapping and ultra-staging in breast cancer and melanoma, such techniques are increasingly used for other organ systems including the gynecologic tract. This review addresses the historical aspects of sentinel lymph node evaluation and reviews current ultra-staging protocols as well as the implications associated with increased detection of low volume metastases.

Lymphoscintigraphy and sentinel lymph node biopsy in vulvar carcinoma: update from a European expert panel

PURPOSE

This study aimed to update the clinical practice applications and technical procedures of sentinel lymph node (SLN) biopsy in vulvar cancer from European experts.

METHODS

A systematic data search using PubMed/MEDLINE database was performed up to May 29, 2019. Only original studies focused on SLN biopsy in vulvar cancer, published in the English language and with a minimum of nine patients were selected.

RESULTS

Among 280 citations, 65 studies fulfilled the inclusion criteria. On the basis of the published evidences and consensus of European experts, this study provides an updated overview on clinical applications and technical procedures of SLN biopsy in vulvar cancer.

CONCLUSIONS

SLN biopsy is nowadays the standard treatment for well-selected women with clinically negative lymph nodes. Negative SLN is associated with a low groin recurrence rate and a good 5-year disease-specific survival rate. SLN biopsy is the most cost-effective approach than lymphadenectomy in early-stage vulvar cancer. However, future trials should focus on the safe extension of the indication of SLN biopsy in vulvar cancer. Although radiotracers and optical agents are widely used in the clinical routine, there is an increasing interest for hybrid tracers like indocyanine-^99mTc-nanocolloid. Finally, it is essential to standardise the acquisition protocol including SPECT/CT images, and due to the low incidence of this type of malignancy to centralise this procedure in experienced centres for personalised approach.

Sentinel node assessment for diagnosis of groin lymph node involvement in vulval cancer

BACKGROUND

Vulval cancer is usually treated by wide local excision with removal of groin lymph nodes (inguinofemoral lymphadenectomy) from one or both sides, depending on the tumour location. However, this procedure is associated with significant morbidity. As lymph node metastasis occurs in about 30% of women with early vulval cancer, accurate prediction of lymph node metastases could reduce the extent of surgery in many women, thereby reducing morbidity. Sentinel node assessment is a diagnostic technique that uses traceable agents to identify the spread of cancer cells to the lymph nodes draining affected tissue. Once the sentinel nodes are identified, they are removed and submitted to histological examination. This technique has been found to be useful in diagnosing the nodal involvement of other types of tumours. Sentinel node assessment in vulval cancer has been evaluated with various tracing agents. It is unclear which tracing agent or combination of agents is most accurate.

OBJECTIVES

To assess the diagnostic test accuracy of various techniques using traceable agents for sentinel lymph node assessment to diagnose groin lymph node metastasis in women with FIGO stage IB or higher vulval cancer and to investigate sources of heterogeneity.

SEARCH METHODS

We searched MEDLINE (1946 to February 2013), EMBASE (1974 to March 2013) and the relevant Cochrane trial registers.

SELECTION CRITERIA

Studies that evaluated the diagnostic accuracy of traceable agents for sentinel node assessment (involving the identification of a sentinel node plus histological examination) compared with histological examination of removed groin lymph nodes following complete inguinofemoral lymphadenectomy (IFL) in women with vulval cancer, provided there were sufficient data for the construction of two-by-two tables.

DATA COLLECTION AND ANALYSIS

Two authors (TAL, AP) 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 used univariate meta-analytical methods to estimate pooled sensitivity estimates.

MAIN RESULTS

We included 34 studies evaluating 1614 women and approximately 2396 groins. The overall methodological quality of included studies was moderate. The studies included in this review used the following traceable techniques to identify sentinel nodes in their participants: blue dye only (three studies), technetium only (eight studies), blue dye plus technetium combined (combined tests; 13 studies) and various inconsistent combinations of these three techniques (mixed tests; 10 studies). For studies of mixed tests, we obtained separate test data where possible.Most studies used haematoxylin and eosin (H&E) stains for the histological examination. Additionally an immunohistochemical (IHC) stain with and without ultrastaging was employed by 14 and eight studies, respectively. One study used reverse transcriptase polymerase chain reaction analysis (CA9 RT-PCR), whilst three studies did not describe the histological methods used.The pooled sensitivity estimate for studies using blue dye only was 0.94 (68 women; 95% confidence interval (CI) 0.69 to 0.99), for mixed tests was 0.91 (679 women; 95% CI 0.71 to 0.98), for technetium only was 0.93 (149 women; 95% CI 0.89 to 0.96) and for combined tests was 0.95 (390 women; 95% CI 0.89 to 0.97). Negative predictive values (NPVs) for all index tests were > 95%. Most studies also reported sentinel node detection rates (the ability of the test to identify a sentinel node) of the index test. The mean detection rate for blue dye alone was 82%, compared with 95%, 96% and 98% for mixed tests, technetium only and combined tests, respectively. We estimated the clinical consequences of the various tests for 100 women undergoing the sentinel node procedure, assuming the prevalence of groin metastases to be 30%. For the combined or technetium only tests, one and two women with groin metastases might be 'missed', respectively (95% CI 1 to 3); and for mixed tests, three women with groin metastases might be 'missed' (95% CI 1 to 9). The wide CIs associated with the pooled sensitivity estimates for blue dye and mixed tests increased the potential for these tests to 'miss' women with groin metastases.

AUTHORS' CONCLUSIONS

There is little difference in diagnostic test accuracy between the technetium and combined tests. The combined test may reduce the number of women with 'missed' groin node metastases compared with technetium only. Blue dye alone may be associated with more 'missed' cases compared with tests using technetium. Sentinel node assessment with technetium-based tests will reduce the need for IFL by 70% in women with early vulval cancer. It is not yet clear how the survival of women with negative sentinel nodes compares to those undergoing standard surgery (IFL). A randomised controlled trial of sentinel node dissection and IFL has methodological and ethical issues, therefore more observational data on the survival of women with early vulval cancer are needed.

Sentinel lymph node biopsy in vulval cancer: systematic review and meta-analysis

BACKGROUND

The purpose of this study was to determine the accuracy of sentinel lymph node (SLN) biopsy with technetium 99 (99mTc) and/or blue dye-enhanced lymphoscintigraphy in vulval cancer.

METHODS

Sensitive searches of databases were performed upto October 2013. Studies with at least 75% of women with FIGO stage IB or II vulval cancer evaluating SLN biopsy with 99mTc, blue dye or both with reference standard of inguinofemoral lymphadenectomy (IFL) or clinical follow-up were included. Meta-analyses were performed using Meta-Disc version 1.4.

RESULTS

Of the 2950 references, 29 studies (1779 women) were included; most of them evaluated 99mTc combined with blue dye. Of these, 24 studies reported results for SLN followed by IFL, and 5 reported clinical follow-up only for SLN negatives. Pooling of all studies was inappropriate because of heterogeneity. Mean SLN detection rates were 94.0% for 99mTc, 68.7% for blue dye and 97.7% for both. SLN biopsy had pooled sensitivity of 95% (95% CI 92-98%) with negative predictive value (NPV) of 97.9% in studies using 99mTc/blue dye, ultrastaging and immunohistochemistry with IFL as reference. Pooled sensitivity for SLN with clinical follow-up for SLN-negatives was 91% (85-95%) with NPV 95.6%. Patients undergoing SLN biopsy experienced less morbidity than those undergoing IFL.

CONCLUSIONS

Sentinel lymph node biopsy using 99mTC, blue dye and ultrastaging with immunohistochemistry is highly accurate when restricted to carefully selected patients, within a rigorous protocol, with close follow-up and where sufficient numbers for learning curve optimisation exist. Patients must make an informed choice between the slightly higher groin recurrence rates of SLN biopsy vs the greater morbidity of IFL.

Effects of previous surgery on the detection of sentinel nodes in women with vulvar cancer

BACKGROUND

There is a growing interest to apply the sentinel node (SN) procedure in the treatment of vulvar cancer. Previous vulvar surgery might disrupt lymphatic patterns and thereby decrease SN detection rates, lengthen scintigraphic appearance time (SAT), and increase SN false-negative rate. The aims of this study were to evaluate the SN detection rates at the Mercy Hospital for Women in Melbourne and to investigate whether previous vulvar surgery affects SN detection rates, SAT, and SN false-negative rate.

METHODS

Data on all patients with vulvar cancer who underwent an SN procedure (blue dye, technetium, or combined technique) from November 2000 to July 2010 were retrospectively collected.

RESULTS

Sixty-five SN procedures were performed. Overall detection rate was 94% per person and 80% per groin. Detection rates in the group of patients who underwent previous excision of the primary tumor were not lower compared with the group without previous surgery or with just an incisional biopsy. There was no statistical significant difference in SAT between the previous excision group and the other patients. None of the patients with a false-negative SN had undergone previous excision.

CONCLUSIONS

Results indicate that previous excision of a primary vulvar malignancy does not decrease SN detection rates or increase SN false-negative rate. Therefore, the SN procedure appears to be a reliable technique in patients who have previously undergone vulvar surgery. Previous excision did not significantly lengthen SAT, but the sample size in this subgroup analysis was small.

Evaluation of preoperative lymphoscintigraphy and sentinel node procedure in vulvar cancer

OBJECTIVE

To assess the value of preoperative lymphoscintigraphy, and to evaluate the validity and feasibility of the sentinel node (SN) procedure in vulvar carcinoma.

STUDY DESIGN

Retrospective clinical and histopathological review of 77 patients with invasive squamous cell carcinoma in vulva who were treated at Karolinska University Hospital Stockholm, Sweden, from 2000 to 2007. The patients underwent SN mapping preoperatively with radioactive tracer and blue dye (n=60) or only blue dye (n=17). The SN was removed separately followed by complete inguinofemoral lymphadenectomy.

RESULTS

The relation between SNs detected on the scintigram and those found during surgery showed good agreement using weighted kappa. The detection rate of SN was 98% for radioisotope plus blue dye, and 94% for blue dye alone. Two cases of false negative SN (false negative rate 2.7%) were found, both with large midline tumors.

CONCLUSION

Preoperative scintigram is a valuable help to identify and localize the SNs and gives the best estimate of the accurate number but cannot determine if unilateral or bilateral groins should be explored in cases of midline tumors. Our results are in favor of using radioisotope and blue dye to identify the SNs. This study support previous reports that the method is not recommended for tumors larger than 40 mm to optimize detection of SN and minimize the false negative detection rate.