A further validation of subareolar injection technique for breast sentinel lymph node biopsy

The detection rate of methylene blue combined with another tracer in sentinel lymph node biopsy of early-stage breast cancer: a systematic review and network meta-analysis

Background

Methylene blue (MB) alone or combined with 99mtechnetium-labeled sulphur colloid (Tc99m) or indocyanine green (ICG) is widely used for sentinel lymph node biopsy (SLNB) of early-stage breast cancer in developing countries and regions. However, studies investigating the effectiveness of MB combined with another tracer have produced heterogeneous results. The purpose of this network meta-analysis (NMA) was to evaluate the detection rate of MB alone, MB + Tc99m, and MB + ICG, and to examine the differences between the 3 methods.

Methods

We conducted a comprehensive electronic literature search on the PubMed, Embase, Web of Science, CNKI, and Wanfang Data databases from inception to October 2021. The meta-analysis included 7,498 patients in 49 studies. The risk of bias for each study was independently assessed as low, moderate, or high using criteria adapted from the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Fixed- and random-effects models were used to calculate pooled estimates. Mixed-comparison analysis using random-effects models. We assessed statistical heterogeneity by I2 statistics and evaluated publication bias using Begg’s test.

Results

The identification rate (IR), false-negative rate (FNR), sensitivity (SEN), and accuracy rate (AR) using MB + Tc99m were 96%, 7%, 93%, and 96%, respectively; the IR, FNR, SEN, and AR using MB + ICG were 97%, 7%, 93%, and 97%, respectively. The NMA found that IR and AR between MB + ICG and MB + Tc99m was OR =1.37 (95% CI: 0.41–4.20) and OR =1.33 (95% CI: 0.56–3.32), respectively.

Discussion

Our results are similar to those of most previous studies, and meta-analysis showed that the MB + Tc99m or MB + ICG mapping methods can be used to obtain higher IR and lower FNR than MB alone. Our NMA showed no statistical significance between MB + Tc99m and MB + ICG with IR and AR. Both MB + Tc99m and MB + ICG can be used as effective mapping methods in SLNB of early-stage breast cancer to improve the detection rate.

Sentinel lymph node biopsy mapped with methylene blue dye alone in patients with breast cancer: A systematic review and meta-analysis

Background

Methylene blue dye is easy to obtain in developing countries and can be used in sentinel lymph node mapping for breast cancer. However, the accuracy of methylene blue alone for sentinel lymph node mapping in breast cancer has not been well defined. In this study, we collected data to assess the feasibility and accuracy of sentinel lymph node biopsy mapped with methylene blue alone in patients with breast cancer.

Methods

We searched the PubMed, EMBASE, and Cochrane Library databases from January 1, 1993, to March 31, 2018. Selected studies had to have a defined group of patients with breast cancer in which MBD alone was used as the mapping technique for SNB.

Results

18 studies were included in this study. The combined identification rate was 91% [95% confidence interval (CI): 88%-94%, I² = 68.3%], and the false negative rate was 13% (95% CI: 9%-18%, I² = 36.7%). The pooled sensitivity, negative predictive value, and accuracy rate were 87% (95% CI: 82%-91%, I² = 37.5%), 91% (95% CI: 87%-93%, I² = 32.4%) and 94% (95% CI: 92%-96%, I² = 29%), respectively.

Conclusions

This meta-analysis found that mapping sentinel lymph node locations with methylene blue dye alone results in an acceptable identification rate but an excessive false negative rate according to the American Society of Breast Surgeons’ recommendations. Caution is warranted when using methylene blue dye alone as the mapping method for sentinel lymph node biopsy.

Sentinel Lymph Node Biopsy in Patients with Pure and High-Risk Ductal Carcinoma in Situ of the Breast

Aims and Background

The role of sentinel lymph node biopsy in patients initially diagnosed with ductal carcinoma in situ resides in determining the predictors of invasive disease. The aim of the present study was to examine the incidence of sentinel lymph node metastases in a selected group of patients, with characteristics of high-risk ductal carcinoma in situ, in order to determine the clinical usefulness of sentinel lymph node biopsy.

Methods

A total of 90 patients with a biopsy diagnosis of ductal carcinoma in situ were treated. Fifty-two patients with high-risk ductal carcinoma in situ had sentinel lymph node biopsy. The following characteristics of the primary tumor were considered as indicative of a risk of invasive disease: presence of palpable mass, mammographic mass, multicentric disease that required mastectomy, and histologically high nuclear grade or non-high nuclear grade with necrosis. Subdermal injections of 99mTc-labeled human albumin and subareolar injection ofblue dye were used for sentinel lymph node identification. All sentinel nodes were sectioned serially and stained with hematoxylin and eosin. Immunohistochemical analysis was performed using a cytokeratin monoclonal antibody.

Results

A positive sentinel lymph node was found in only one patient (1.9%). The patient had a double lesion, and core-needle biopsy showed an atypical ductal hyperplasia and a intermediate degree of ductal carcinoma in situ. At pathologic review of the specimen, no invasive aspect was detected.

Conclusions

The results of our study indicate that sentinel lymph node metastasis in pure ductal carcinoma in situ is extremely uncommon. We therefore suggest that sentinel lymph node biopsy might be indicated for patients with ductal carcinoma in situ detected as a palpable mass or as large extensive microcalcifications, as well as for patients who are undergoing mastectomy, especially with immediate reconstruction.

Selective sentinel lymph node biopsy in male breast cancer

OBJECTIVE

To evaluate the reproducibility of the sentinel lymph node (SLN) technique in male breast cancer.

MATERIAL AND METHODS

We retrospectively analysed 21 male patients diagnosed with breast cancer in our hospital from 2008 to 2016 with, at least, 18 months follow-up. Fifteen patients underwent selective sentinel lymph node biopsy (SLNB) following the usual protocols with peritumoral injection of 18.5-111MBq of ^99mTc-nanocoloides and acquisition of planar images 2hours after the injection. In 2 cases it was necessary to perform a SPECT/CT to locate the SLN. Immunohistochemistry and molecular techniques (OSNA) were used for their analysis. Six patients did not undergo SLNB because they had pathological nodes or distant disease at the time of diagnosis.

RESULTS

SLNB was performed in 15 patients. The SLN was negative in 6 patients and positive in the remaining 9. Three patients with positive SLNB did not need axillary lymphadenectomy because of the low number of copies by molecular analysis OSNA. Axillary lymphadenectomy was performed in the remaining 6 patients with the result of 4 positive axillary lymphadenectomies and 2 that did not show further extension of the disease.

CONCLUSIONS

According to our experience, SLNB in males is a reproducible, useful, safe and reliable technique which avoids unnecessary axillary lymphadenectomy and prevents the appearance of undesirable effects.

Blue dye for identification of sentinel nodes in breast cancer and malignant melanoma: a systematic review and meta-analysis

The combined technique (radioisotope and blue dye) is the gold standard for sentinel lymph node biopsy (SLNB) and there is wide variation in techniques and blue dyes used. We performed a systematic review and meta-analysis to assess the need for radioisotope and the optimal blue dye for SLNB. A total of 21 studies were included. The SLNB identification rates are high with all the commonly used blue dyes. Furthermore, methylene blue is superior to iso-sulfan blue and Patent Blue V with respect to false-negative rates. The combined technique remains the most accurate and effective technique for SLNB. In order to standardize the SLNB technique, comparative trials to determine the most effective blue dye and national guidelines are required.

Sentinel node biopsy in early breast cancer at the Hospital Comarcal La Linea (Spain)

Objective

Our objective was to determine the identification and the percentage of false negatives in sentinel node biopsies in patients with early breast cancer at the Hospital La Línea (Spain), during the period between November 2007 and September 2010.

Methods

We collected 50 patients with early breast cancer, without clinical and ultrasonographic involvement of axillary nodes, from November 2007 to September 2010. We used the vital dye in the first 20 patients and the combined technique of vital dye and albumin labelled with technetium 99 in the other 30 patients. The site of injection for patients using blue dye was subdermal for palpable tumours and periareolar for non-palpable tumours. The technique of injection with the radioisotope for patients for palpable and most non-palpable tumours was the periareolar technique. We used albumin labelled with technetium 99. In seven patients with non-palpable tumours, we used the sentinel node occult lesion localisation (SNOLL) technique. The sentinel node biopsy was examined during surgery, with the frozen section examination and imprint as follows: the sentinel node was cut in three transversal sections along the axis and five frozen sections of each portion were done at a distance of 60 μm each; in total, 15–20 frozen sections and three imprints were done for each sentinel node. The axillary dissection was completed in the first 17 patients, and we performed total axillary dissection on the remaining patients if the sentinel node was positive for metastasis.

Results

The sentinel nodes were identified in 49 of 50 patients (98%). The patient in whom we did not identify the sentinel node was a patient in the combined technique. The number of nodes identified in the patients with vital dye was one sentinel node, and with the combined technique, it was two sentinel nodes. The false-negative rate was 8% (four patients); the micrometastasis was the principal factor of the false-negative rate (p < 0.05). The cases of false negatives were present at the beginning of the study with the use of the blue dyes; this factor was statistically significant (p < 0.05). The tumour size, the vascular invasion, and the periganglionar adipose tissue invasion were statistically significant for the presentation of axillary metastasis (p < 0.05).

Conclusion

This study shows that the micrometastasis and the use of vital dye were the principal factors for the presentation of the false-negative rate. The size of the tumour, the vascular invasion, and the periganglionar adipose tissue invasion were statistically significant for the appearance of the axillary metastasis.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

BACKGROUND

In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS

We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS

There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS

The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.

Debating the mathematical model to validate the sentinel lymph biopsy techniques in breast cancer patients. The danger of bias and its practical implications

BACKGROUND

Sentinel node biopsy (SNB) is an effective alternative to axillary lymph node dissection (ALD) for axillary staging. SNB (test) needs a validation period in which ALD (the gold standard) is always performed. Sensitivity, specificity and predictive values (PV) are used to define the accuracy of the procedure. We hypothesise that, during the period of validation, a bias is produced if the result of SNB is included as a part of the ALD.

PATIENTS AND METHODS

A hypothetical population of 350 patients was analysed. First analyses were performed by including the sentinel lymph node as a part of 'the rest of the axilla'. Second analyses were re-done according to our theory, and sentinel lymph node was considered outside 'the rest of the axilla'. Sensitivity, specificity and PV were compared for both models.

RESULTS

First group (classic) - sensitivity: 94%; specificity: 100%; positive PV: 100%; negative PV: 97%. Second group (new proposed model) - sensitivity: 87%; specificity: 81%; positive PV: 44%; negative PV: 97%.

CONCLUSION

The classic concept of sentinel lymph node to calculate sensitivity, specificity and positive PV can result in a bias. The magnitude of this bias will vary in terms of the obtained values, but its direction is always optimistic.

Sentinel node imaging in breast cancer using superficial injections: technical details and observations

INTRODUCTION

Sentinel lymph node (SLN) biopsy is the evolving standard of care for the management of early breast cancer. Accurate identification of the SLN is paramount for success of this procedure. Various techniques are described for SLN identification, but the superficial injection techniques, advocated by the UK National Training Programme (NEW START), are validated, reproducible and rapid. Pre-operative lymphoscintigraphy provides a road map for the surgeon and requires a reporting template.

METHODS

As one of the NEW START training institutions in the UK practising this technique, we reviewed a mature series of 100 unselected, consecutive SLN lymphoscintigraphy procedures. We correlated the imaging, operative and pathology findings and have provided technical details of the technique and a template for reporting SLN lymphoscintigrams.

RESULTS

The SLN localisation rate was 99% with one failed imaging. Seven patients required delayed imaging. The mean activity of the radiocolloid injected was 14.4MBq (range 8.3-23 MBq). The SLNs were visualised in the ipsilateral axilla in 98 images, intramammary in 3, and internal mammary in 1. A mean of 1.35 nodes were classified as 'True' SLNs on imaging criteria. Intra-operatively, a mean of 1.91 SLNs were excised. 32 of 116 hot and blue nodes, 7 of 15 only blue nodes, 13 of 47 only hot and 7 of 13 parasentinel nodes harboured metastases.

CONCLUSION

The NEW START recommended, combined superficial injection techniques, have high localisation rates. Pre-operative sentinel node imaging is recommended and a template for reporting is provided.

Sentinel lymph node biopsy: technique validation at the Setúbal Medical Centre, Portugal

Aims:

To evaluate the accuracy of sentinel lymph node biopsy in breast cancer patients at this institution, using combined technetium-99m (^99mTc) sulphur colloid and patent blue vital dye.

Methods:

From March 2007 to July 2008, 50 patients with a tumour of less than 3 cm and with clinically negative axillary lymph nodes underwent sentinel lymph node biopsy (SLNB), followed by axillary lymph node dissection (ALND). Sub-areolar ^99mTc sulphur colloid injection was performed the day before surgery, and patent blue vital dye was also injected sub-areolarly at least 5 minutes before surgery. Sentinel lymph node was identified during the surgical procedure, using a gamma probe and direct vision. All sentinel nodes underwent frozen section analysis. Later haematoxylin and eosin staining and immunohistochemical analysis were performed. Finally, SLNB was compared with standard ALND for its ability to accurately reflect the final pathological status of the axillary nodes.

Results:

The sentinel lymph node (SLN) was identified in 48 of 50 patients (96%). The number of sentinel lymph nodes ranged from one to four (mean 1.48) and non-sentinel nodes ranged from seven to 27 (mean 14.33). Of the 48 patients with successfully identified SLNs, 29.17% (14/48) were histologically positive. Sensivity of the SLN to predict axilla was 93.75%; accuracy was 97.96%. The SLN was falsely negative in one patient—6.25% (1/16).

Conclusions:

The SLNB represents a major advance in the surgical treatment of breast cancer as a minimally invasive procedure predicting the axillary lymph node status. This validation study demonstrates the accuracy of the SLNB and its reasonable false negative rate when performed in our institute. It can now be used as the standard method of staging in patients with early breast cancer at this institution.

Quantum dots in axillary lymph node mapping: biodistribution study in healthy mice

Background

Breast cancer is the first cause of cancer death among women and its incidence doubled in the last two decades. Several approaches for the treatment of these cancers have been developed. The axillary lymph node dissection (ALND) leads to numerous morbidity complications and is now advantageously replaced by the dissection and the biopsy of the sentinel lymph node. Although this approach has strong advantages, it has its own limitations which are manipulation of radioactive products and possible anaphylactic reactions to the dye. As recently proposed, these limitations could in principle be by-passed if semiconductor nanoparticles (quantum dots or QDs) were used as fluorescent contrast agents for the in vivo imaging of SLN. QDs are fluorescent nanoparticles with unique optical properties like strong resistance to photobleaching, size dependent emission wavelength, large molar extinction coefficient, and good quantum yield.

Methods

CdSe/ZnS core/shell QDs emitting around 655 nm were used in our studies. 20 μL of 1 μM (20 pmol) QDs solution were injected subcutaneously in the anterior paw of healthy nude mice and the axillary lymph node (ALN) was identified visually after injection of a blue dye. In vivo fluorescence spectroscopy was performed on ALN before the mice were sacrificed at 5, 15, 30, 60 min and 24 h after QDs injection. ALN and all other organs were removed, cryosectioned and observed in fluorescence microscopy. The organs were then chemically made soluble to extract QDs. Plasmatic, urinary and fecal fluorescence levels were measured.

Results

QDs were detected in ALN as soon as 5 min and up to 24 h after the injection. The maximum amount of QDs in the ALN was detected 60 min after the injection and corresponds to 2.42% of the injected dose. Most of the injected QDs remained at the injection site. No QDs were detected in other tissues, plasma, urine and feces.

Conclusion

Effective and rapid (few minutes) detection of sentinel lymph node using fluorescent imaging of quantum dots was demonstrated. This work was done using very low doses of injected QDs and the detection was done using a minimally invasive method.

Sentinel lymph node biopsy in multiple breast cancer using subareolar injection of the tracer

We performed subdermal injection of (99m)Tc-labelled albumin combined with subareolar (SA) injection of blue dye to axillary lymphatic mapping and sentinel lymph node biopsy (SLNB) in patients with multifocal and multicentric breast cancer to evaluate the feasibility and accuracy of this technique. A retrospective analysis of our experience on 235 SLNB showed that 30(12.7%) had multiple cancer (MC) on final pathologic examination and was considered in relation to the aim of the study. Mean age was 57.19 years (range 24-90). Mean number of SLNs identified was 1.93 (range 1-5). Mean number of axillary LNs examined was 18.10 (range 12-27). Overall successful identification was 100% with a false negative (FN) rate of 6.25%. Overall accuracy of lymphatic mapping and sensitivity was 96.6% and 93.7%, respectively. SLNB using the SA injection technique may be an alternative to complete axillary dissection in patients with multiple breast cancers and a clinically negative axilla.