Reliability of sentinel node assay in vulvar cancer: the first Croatian validation trial

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.

Detection of sentinel lymph node in vulvar cancer using 99mTc-labeled colloid lymphoscintigraphy, blue dye, and indocyanine-green fluorescence: a meta-analysis of studies published in 2010-2020

OBJECTIVES

Sentinel lymph node (SLN) biopsy is widely accepted in the surgical staging of early vulvar cancer, although the most accurate method for its identification is not yet defined. This meta-analysis aimed to determine the technique with the highest pooled detection rate (DR) for the identification of SLN and compare the average number of SLNs detected by planar lymphoscintigraphy (PL), single-photon emission computed tomography/computed tomography (SPECT/CT), blue dye and indocyanine green (ICG) fluorescence.

METHODS

The meta-analysis was conducted according to the PRISMA guideline. The search string was: "sentinel" and "vulv*", with date restriction from 1st January 2010 until Dec 31st, 2020. Three investigators selected studies based on: (1) a study cohort or a subset of a minimum of 10 patients with vulvar cancer undergoing either PL, SPECT/CT, blue-dye, or ICG fluorescence for the identification of SLN; (2) the possibility to extrapolate the DR or the average number of SLNs detected by a single technique (3) no evidence of other malignancies in the patient history.

RESULTS

A total of 30 studies were selected. In a per-patient and a per-groin analysis, the DR for SLN of PL was respectively 96.13% and 92.57%; for the blue dye was 90.44% and 66.21%; for the ICG, the DR was 91.90% and 94.80%. The pooled DR of SPECT/CT was not calculated, since only two studies were performed in this setting. At a patient-based analysis, no significant difference was documented among PL, blue dye, and ICG (p = 0.28). At a per-groin analysis, PL and ICG demonstrated a significantly higher DR compared to blue dye (p < 0.05). The average number of SLNs, on a per-patient analysis, was available only for PL and ICG with a median number of 2.61 and 1.78 lymph nodes detected, respectively, and no significant statistical difference.

CONCLUSIONS

This meta-analysis favors the use of ICG and PL alone and in combination over blue dye for the identification of the SLN in vulvar cancer. Future studies may investigate whether the combined approach allows the highest DR of SLN in patients with vulvar cancer.

Safety and Benefit Of Sentinel Lymph Nodes Biopsy Compared to Regional Lymph Node Dissection in Primary Vulvar Cancer Patients Without Distant Metastasis and Adjacent Organ Invasion: A Retrospective Population Study

Background

The safety and benefit of sentinel lymph node biopsy (SLNB) compared with regional lymph node dissection (RLND) and no lymph nodes removed (NA) in patients with vulvar squamous cell cancer (VSCC) was not well studied.

Methods

A retrospective analysis on VSCC patients without distant metastasis and adjacent organ invasion from the Surveillance, Epidemiology, and End Results Program database between 2004 and 2016 was carried out. Within subgroups stratified by negative (LN−) or positive (LN+) regional lymph node findings, inverse probability weighting (IPW) adjusted multivariate Fine-Gray compete risk (CR) model and accelerated failure time (AFT) model was used to investigate the factors associated with and cancer-specific survival (CSS) and overall survival (OS).

Results

Of the 3,161 VSCC patients treated with surgery, 287 (9.1%) underwent SLNB, 1,716 (54.3%) underwent RLND, and 1,158 (36.6%) had no regional lymph nodes removed. As illustrated by IPW adjusted multivariate regressions, SLNB was significantly associated with prolonged CSS (LN−, adjusted sub-proportional hazard ratio [sHR] = 0.42; 95% confidence interval [CI], 0.19–0.93; P=0.032; LN+, adjusted sHR = 0.29; 95% CI, 0.16–0.54, P<0.001) and OS (LN−, adjusted time ratio [TR] = 1.38; 95% CI, 0.82–2.32; P=0.226; LN+, adjusted TR = 2.68; 95% CI, 1.73–4.14; P<0.001), although the effect of SLNB on OS was not significant within the LN− cohort. Moreover, SLNB led to improved CSS (adjusted sHR = 0.40; 95% CI, 0.23–0.70; P = 0.001) and OS (adjusted TR=1.15, 95% CI 0.76-1.73, P=0.279) compared with NA. Age was a significant prognostic factor of CSS and OS, whereas tumor size, surgery type, and invasion depth were not.

Conclusions

SLNB leads to significantly prolonged CSS and OS in VSCC surgery patients without distant metastasis and adjacent organ invasion than RLND, except for the similar OS in the LN− cohort. SLNB could be carried out preferentially for VSCC surgery patients without distant metastasis and adjacent organ invasion, irrespective of tumor size, surgery type, invasion depth, and regional lymph nodes metastasis. Further prospective clinical trials are warranted to confirm the findings of this study.

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.

Relevance of computerized tomography in the preoperative evaluation of patients with vulvar cancer: a prospective study

Background

The purpose of the study was to determine whether inclusion of computerized tomography (CT) in the prospective evaluation of vulvar cancer changed the surgical treatment strategy in terms of detection of lymph node metastases, tumor spread and comorbidity, and additionally to examine the logistical influence of adding further examinations prior to treating out-hospital patients referred from geographically distant areas.

Methods

During an 8 month period we conducted a prospective study of patients with newly diagnosed or recurrent vulvar cancer consecutively referred to Copenhagen University Hospital, Rigshospitalet. The patients underwent a gynecological examination, chest x-ray and a preoperative CT scanning of the chest, abdomen and pelvis. It was registered whether the radiological findings regarding the extent of the tumor, lymph node involvement, incidental findings and comorbidity changed the surgical treatment plan. Further, the logistical influence of the long referral distances was registered.

Results

Thirty patients with a median age of 69 years (range 44–93 years) were included in the study. CT did not significantly change the initial surgical treatment plan for the patients. CT did not reveal lymph node enlargement outside the inguinofemoral area and was inaccurate compared to the sentinal node examination of the local lymph nodes. CT diagnosed no cases with distant metastases from the primary malignancy, but two cases with a secondary malignant disease were found.

Conclusions

CT scanning has no clinical impact as a routine screening examination prior to surgery. It may delay treatment, but can add important information when clinically indicated.

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.