Blue dye is sufficient for sentinel lymph node biopsy in breast cancer

Rapid, Non-Invasive, Accurate Diagnosis and Efficient Clearance of Metastatic Lymph Nodes

Sentinel lymph node (SLN) biopsy is currently the standard procedure for clinical cancer diagnosis and treatment, but still faces the risks of false negatives and tumor metastasis, as well as time-consuming pathological evaluation procedure. Herein, we proposed a near-infrared-II (NIR-II, 1000-1700 nm) theranostic nanosystem (FLAGC) for rapid, non-invasive, accurate diagnosis and efficient clearance of metastatic lymph nodes in breast cancer. Initialized by chlorin e6 (Ce6), a pH-sensitive amphiphilic amino acid fluorenylmethoxycarbonyl-L-histidine (Fmoc-His) was assembled with Gd3+, luminol, and AgAuSe quantum dots (AAS QDs) to form FLAGC. In FLAGC, luminol and AAS QDs form a NIR-II chemical resonance energy transfer (CRET) system (Luminol-AAS); Ce6 initiates the assembly and also serves as a photosensitizer. Upon subcutaneous injection, FLAGC is easily drained into SLNs, achieving their precise localization. Subsequently, the acidity of tumor microenvironment triggers the rapid disassembly of FLAGC, exposing Luminol-AAS. myeloperoxidase (MPO) secreted by tumor-associated macrophages and neutrophils in SLNs mediates the oxidation of luminol, lighting up AAS QDs through the CRET process for precise diagnosis of metastatic lymph nodes. Moreover, highly efficient clearance of positive lymph nodes is achieved through Ce6-mediated photodynamic therapy. Our strategy provides a new paradigm for identifying and eliminating clinically metastatic lymph nodes.

Tracing Sentinel Lymph Nodes and Inhibiting Lymphatic Metastasis with TiN Nanobipyramids Through Photothermal Therapy

Background

The lymphatic system is the major route of cancer metastasis, and sentinel lymph nodes (SLNs) are the first station for the spread of cancer cells. Accurate identification of SLNs by tracers during surgery is crucial for SLN biopsy and lymphadenectomy. However, conventional monomodal tracers such as blue dyes and carbon nanoparticles often induce a misjudgment of SLNs and thus are still unsatisfying for clinical applications. In addition, SLN imaging agents with therapeutic capabilities to achieve perfect theranostics have been less exploited.

Purpose

Titanium nitride (TiN) nanostructures have the advantages of high stability and low cost and show superior plasmonic properties over both the visible and near-infrared (NIR) regions. Herein we report on the synthesis of TiN nanobipyramids (NBPs) with large sizes for multimodal SLN mapping.

Methods

A hydrothermal method and post nitridation treatment were used to prepare the TiN NBPs. Bright- and dark-field imaging of SLNs with TiN NBPs were performed. The effect of TiN NBP size on SLN tracing was studied. The effect of TiN NBP-based photothermal ablation of SLNs combined with removal of primary tumors on pulmonary metastasis was studied.

Results

The TiN NBPs with dual bright- and dark-field imaging functions show high drainage in lymph nodes and thus can act as a potential substitute for SLN tracing. Moreover, owing to the superior plasmonic properties of TiN nanostructures, the produced TiN NBPs show a high photothermal conversion efficiency under 1064 nm laser irradiation. TiN NBP-based photothermal ablation of metastatic LNs in the second NIR window (NIR-II) combined with surgical removal of primary tumors shows remarkable inhibition of pulmonary metastasis.

Conclusion

This study not only demonstrates TiN NBPs as a new tracer for SLN mapping, but also presents a strategy for the photothermal ablation of lymph nodes in NIR-II for the inhibition of lymphatic metastasis.

Sentinel Lymph Node Biopsy by Lymphatic Flare Technique: a Feasibility Study-"The FLAIR Is in the FLARE"

Background

Sentinel lymph node (SLN) biopsy is a standard procedure in evaluating the status of node negative axilla. Numerous techniques have been described in literature. We hereby describe a new technique of intradermal injection of blue dye called the lymphatic flare technique.

Methods

The study was conducted in two phases over a year from August 2020 to May 2021with an internal audit to validate and standardize the technique in January 2021.

Results

Between August 2020 and December 2020, 32 patients were evaluated for validation of this technique by two senior surgeons, which yielded a SLN identification rate of 93.75% (30 out of 32). After validating, standardizing, and educating the entire surgical team of the technique, another consecutive 27 patients were evaluated. The SLN identification rate increased to 100% (27 out of 27). Overall, SLN positivity for cancer was 16.6% (10 out of 60).

Conclusion

SLN identification by the lymphatic flare technique is feasible, accurate, and reproducible.

Near-infrared upconversion multimodal nanoparticles for targeted radionuclide therapy of breast cancer lymphatic metastases

The theranostics of lymph node metastasis has always been one of the major obstacles to defeating breast cancer and an important decisive factor in the prognosis of patients. Herein, we design NaGdF₄:Yb,Tm@NaLuF₄ upconversion nanoparticles with PEG and anti-HER2 monoclonal antibody (trastuzumab, Herceptin) (NP-mAb), the delivery of NP-mAb through the lymphatic system allows for effective targeting and accumulation in lymphatic metastasis. Combination of radionuclides ⁶⁸Ga and ¹⁷⁷Lu could be chelated by the bisphosphate groups of NP-mAb. The obtained nanoprobe (NP-mAb) and nanonuclear drug (⁶⁸Ga-NP-mAb or ¹⁷⁷Lu-NP-mAb) exhibited excellent stability and show high accumulation and prolong retention in the lymph node metastasis after intratumoral injection into the foot pad by near-infrared fluorescence (NIRF), single-photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging. Utilizing the β-rays released by ¹⁷⁷Lu, ¹⁷⁷Lu-NP-mAb could not only decrease the incidence of lymph node metastasis, but also significantly decrease the volumes of lymph node metastasis. Additionally, ¹⁷⁷Lu-NP-mAb induce no obvious toxicity to treated mice through blood routine, liver and kidney function assay. Therefore, nanoprobe and nanonuclear drug we designed could be acted as excellent theranostics agents for lymph node metastasis, providing potential alternatives diagnose and treatment option for lymph node metastasis.

A Randomized Prospective Non-Inferiority Trial of Sentinel Lymph Node Biopsy in Early Breast Cancer: Blue Dye Compared with Indocyanine Green Fluorescence Tracer

Simple Summary

This randomized study was conducted to evaluate sentinel lymph node biopsy with indocyanine green (ICG) compared with blue dye as a tracer in women with early breast cancer without any sign of lymph node invasion. ICG is a fluorescent tracer well known in medical practice for 50 years that is used as tracer of sentinel lymph nodes in numerous types of cancers other than breast cancer. This tracer is cheaper than radioactive tracers, with an easy learning curve.

Abstract

Background: Indocyanine green (ICG) is a promising tracer for sentinel lymph node biopsy in early breast cancer. This randomized study was conducted to evaluate sentinel lymph node biopsy with ICG compared with blue dye as a tracer in woman with early breast cancer without any sign of lymph node invasion. Methods: Between January 2019 and November 2020, 240 consecutive women with early breast cancer were enrolled and randomized to sentinel lymph node biopsy using ICG or blue dye. The primary endpoint was the sentinel lymph node detection rate in both arms. Results: ICG was used in 121 patients and detected sentinel lymph nodes in all patients (detection rate, 100%; 95% CI: 96.9–100.0) while blue dye was used in 119 patients and detected sentinel lymph nodes in 116 patients (detection rate: 97.5%, 95% CI: 92.9–99.1). This analysis indicated the non-inferiority of ICG vs. blue dye tracer (90%CI: −1.9–6.9; p = 0.0009). Conclusion: ICG represents a new promising tracer to detect sentinel lymph nodes in early breast cancer with a detection rate similar to other conventional tracers, and is associated with easy learning and low cost. Our result suggest that this technique is a good alternative to avoid radioactive isotope manipulation.

Sentinel lymph node mapping with patent blue dye in patients with breast cancer: a retrospective single institution study

Background

Since the end of the last century, sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) as standard of care for axillary staging in early breast cancer in patients without any clinical sign of axillary lymph node infiltration. The worldwide most frequently used mapping method consists in the injection of radioactive technetium-99 isotope alone or in combination with blue dye. As a specific infrastructure and dedicated personnel are needed for the use of a radioactive tracer, the CHC in Liege (Belgium) decided to test the use of patent blue dye alone to detect sentinel lymph nodes in a large consecutive cohort of patients and compared the results with radioactive mapping methods and guidelines recommendations.

Methods

Patent blue dye was used in 456 consecutive patients with early breast cancer who underwent conservative breast cancer surgery or radical mastectomy between 1/1/2000 and 31/12/2007 in a community hospital (CHC Liège, Belgium). After SLNB, an ALND was performed in each patient.

Results

Sentinel lymph nodes were identified in 444 patients among the 456 patients evaluated by this mapping method during this time period, which represents a detection rate of 97.4%. Infiltrated lymph nodes were detected in 32.7% of patients (149/456) while in the 444 patients with sentinel lymph nodes identified and resected, 137 patients have at last one positive lymph node (30.9%). The false negative rate was 4.9% and the predictive negative value was 97.7% with the blue dye mapping method.

Conclusions

In addition of the simplicity of the method and the large economic advantage, SNLB using blue dye alone showed a quite acceptable performance in our retrospective analysis concerning its ability to find the SLN as well as its reliability to remove the good ones.

Techniques for sentinel node biopsy in breast cancer

INTRODUCTION

Sentinel node biopsy (SNB) is the standard of care in women with breast cancer (BC) and clinically non suspicious axillary lymph nodes (LNs), due to its high negative predictive value (NPV) in the assessment of nodal status. SNB has significantly reduced complications related to the axillary lymph node dissection, such as lymphedema and upper limb dysfunction.

EVIDENCE ACQUISITION

The gold standard technique for SNB is the blue dye (BD) and technetium labelled nanocolloid (Tc-99m) double technique. However, nuclear medicine is not available in all Institutions and several new tracers and devices have been proposed, such as indocyanine green (ICG) and superparamagnetic iron oxides (SPIO). All these techniques show an accuracy and detection rate not inferior to that of the standard technique, with different specific pros and cons. The choice of how to perform a SNB primarily depends on the surgeon's confidence with the procedure, the availability of nuclear medicine and the economic resources of the Institutions. In this setting, new tracers, hybrid tracers and imaging techniques are being evaluated in order to improve the detection rate of sentinel lymph nodes (SNs) and minimize the number of unnecessary axillary surgeries through an accurate preoperative assessment of nodal status and to guide new minimally invasive diagnostic procedures of SNs. In particular, the contrast-enhanced ultrasound (CEUS) is an active field of research but cannot be recommended for clinical use at this time.

EVIDENCE SYNTHESIS

The ICG fluorescence technique was superior in terms of DR, as well as having the lowest FNR. The DR descending order was SPIO, Tc, dual modality (Tc/BD), CEUS and BD.

CONCLUSIONS

This paper is a narrative review of the most common SNB techniques in BC with a focus on recent innovations.

Comparison between sentinel lymph node hybrid scintigraphy and blue dye technique in breast cancer patients: An institutional experience

To compare the detection efficacy of radionuclide lymphoscintigraphy (LS) versus patent blue dye (PBD) technique for hidden sentinel lymph node (SLN) in breast cancer patients and to determine which modality is better for SLN detection. One hundred and thirty-four early stage breast cancer female patients with clinically negative axilla who underwent post technetium-99m nanocolloid injection single photon emission computed tomography (SPECT-CT) for negative SLN on planar imaging were studied prospectively between 2015 and 2017. Following SPECT-CT, patients underwent peroperative gamma probe count detection GP-CD and PBD technique. Visually, blue stained ± hot nodes were surgically removed and subjected to histopathological analysis. The detection rate by individual method was calculated. Kappa statistics were applied to calculate overall agreement between radioisotope and PBD techniques for diagnostic value assessment. One hundred and thirty-four patients underwent SPECT-CT LS and PBD injection. Mean age: 47 ± 7.6 years (range: 26–82 years). Forty-nine (36.6%) had T1 and 85 (63.4%) T2. SPECT-CT LS detected SLN in 105/134 cases (success rate: 78.4%), later GP-CD localized “hot nodes” in additional 20 cases (success rate: 93.3%). The PBD successfully localized SLN in 131/134 (97.8%) cases. Three cases remained negative on both radioisotope and PBD localization, which on subsequent nodal dissection had metastatic disease. All SLNs detected on SPECT-CT showed blue dye uptake. In 112 cases, more than one SLN was surgically removed. Frozen section analysis of excised SLNs showed metastasis in 31%. Overall moderate agreement (k = 0.56) was calculated. No statistically significant difference was seen between isotope detection and PBD. Radionuclide sentinel mapping has good detection rate particularly combined with peroperative GP-CD. The PBD has added value to reduce false-negative rate of SLN mapping and can substitute radionuclide imaging with negative results.

Real-Time Visualization of Lymphatic Flow to Sentinel Lymph Nodes by Contrast-Enhanced Ultrasonography with Sonazoid in Patients with Breast Cancer

Contrast-enhanced ultrasonography with Sonazoid (SNZ) enables real-time visualization, resulting in more precise identification of lymphatic flow to sentinel lymph nodes (SLNs). This study aimed to classify lymphatic drainage patterns to SLNs. Patients (n = 75) with T1-2 N0 M0 breast cancer received a periareolar injection of SNZ to identify SNZ-enhanced SLNs (SNZ-SLNs), followed by SLN biopsy with blue dye. The lymphatic drainage patterns were classified into four types: type A, single lymphatic route/single SLN; type B, multiple lymphatic routes/single SLN; type C, single lymphatic route/multiple SLNs; and type D, multiple lymphatic routes/multiple SLNs. SLNs were successfully identified in all patients using both blue dye and SNZ. The drainage lymphatic pathways identified were as follows: type A in 53 cases (70.7%), type B in seven (9.3%), type C in eight cases (10.7%) and type D in seven (9.3%). SNZ-SLN biopsy is a technically simple method with a 100% identification rate, enabling the real-time visualization of lymphatic flow to SNZ-SLNs.

Comparative study of indocyanine green combined with blue dye with methylene blue only and carbon nanoparticles only for sentinel lymph node biopsy in breast cancer

Purpose

The combination of indocyanine green and methylene blue (ICG + MB) was reported to be an efficient tracer method in sentinel lymph node biopsy (SLNB). However, whether this method is superior to MB only or carbon nanoparticles (CN) is controversial. This study was to evaluate the efficacy of the three methods in SLNB for breast cancer, and to analyze its influencing factors.

Methods

One hundred eighty patients with early breast cancer were recruited and randomly divided into 3 groups. Each group comprising of 60 patients with SLNB using ICG + MB, MB, and CN, respectively. Then the 3 groups were compared in detection rate, mean number of SLNs, and the detection rates and number of metastatic sentinel lymph nodes (SLNs).

Results

The detection rate of SLNs was 100% (60 of 60) in ICG + MB group, 96.7% (58 of 60), and 98.3% (59 of 60) in MB and CN group, respectively, with no significant difference (P = 0.362). Totally, 204 SLNs (mean ± standard deviation [SD] [range], 3.4 ± 1.4 [2–8]) were detected in ICG + MB group, 102 (1.7 ± 0.7 [0–3]) and 145 (2.4 ± 0.7 [0–6]) in MB and CN group, indicating significant difference (P < 0.001). The detection rate of metastatic SLN was 23.3% (14 of 60) in ICG + MB group, which was higher than 18.3% (11 of 60) and 20% (11 of 60) in MB and CN group, respectively, but showed no statistical significance (P = 0.788).

Conclusion

ICG + MB method was superior to MB only and CN only methods in the mean number of SLNs, thus predicting axillary lymph node metastasis more accurately. Therefore, in areas where the standard method is not available, ICG + MB may be more suitable as an alternative tracer for SLNB.

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.

Predictive factors of axillary metastasis in patients with breast cancer and positive sentinel lymph node biopsy

OBJECTIVE

to evaluate the risk factors for the presence of non-sentinel axillary metastatic disease in patients with breast cancer and positive sentinel node biopsy. Methods: retrospective cross-sectional study of women with breast cancer operated at the Cancer Institute of Ceará between 2002 and 2012 and submitted to sentinel lymph node biopsy.

RESULTS

Among 946 breast cancer patients, 331 underwent sentinel lymph node biopsy, which was positive in 83. These patients underwent axillary lymphadenectomy and 39 (46%) had metastases in other axillary lymph nodes. The variables that were significant for additional axillary disease included Ki67>14 (p=0.043), angiolymphatic invasion (p=0.01) and tumor size (p=0.027). No association was observed with estrogen, progesterone, tumor grade and Her-2 receptors.

DISCUSSION

the presence of angiolymphatic invasion and tumor size have also been related to additional axillary metastasis in other studies. In addition to these variables, the same predictive effect was observed when we evaluated Ki67. The validation of these results may allow the customization of breast cancer treatment, which may reduce its morbidity.

CONCLUSION

angiolymphatic invasion, tumor size (T3/T4) and Ki67>14 were factors predictive of axillary metastasis involvement in addition to the sentinel lymph node.

Evolution in sentinel lymph node biopsy in breast cancer

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in clinically node-negative (cN0) breast cancer patients without neoadjuvant chemotherapy (NAC). The application of SLNB in patients receiving NAC has also been explored. Evidence supports its use after NAC in pretreatment cN0 patients. Nonetheless, its routine use in all the pretreatment node-positive patients who become cN0 after NAC is unjustified due to the unacceptably high false-negative rate, which can be improved in a subset of patients. Axillary surgery omission in selected patients with a low risk of ALN metastasis has gained more and more research interest because the SLNs are tumor-free in more than 70% of all patients. To avoid drawbacks of conventional mapping methods, novel techniques for SLN detection have been developed and shown to be highly accurate in patients with early breast cancer. This article reviews the progress in SLNB in patients with breast cancer.

Comparison of sentinel lymph node biopsy guided by indocyanine green, blue dye, and their combination in breast cancer patients: a prospective cohort study

BACKGROUND

Recent studies show that near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has the potential to improve the performance of sentinel lymph node (SLN) mapping. The current cohort study was designed to assess the value of the combination of ICG and methylene blue (MB) dye in patients undergoing SLN biopsy.

METHODS

A prospective self-controlled trial was designed to detect the difference in the detection efficacies of ICG, MB, and combined ICG and MB (ICG + MB) navigation methods. Between 2010 and 2013, 198 consecutive early breast cancer patients eligible for sentinel lymph node biopsy were enrolled and 200 biopsy procedures were performed by injection of both ICG and MB. SLNs were searched and removed under the guidance of fluorescence and/or blue dye. The mapping characteristics, the detection rate of SLNs and positive SLNs, and the number of SLNs of ICG, MB, and ICG + MB were compared. Injection safety of ICG and MB was evaluated.

RESULTS

Fluorescence imaging of lymphatic flow, which is helpful to locate the incision site, could be seen in 184 of 200 procedures. The nodal detection rate of ICG, MB, and ICG + MB samples was 97, 89, and 99.5% (χ 2 = 26.2, p < 0.001), respectively, with the combination method yielding a superior identification result. The addition of ICG to the MB method resulted in the identification of more lymph nodes (median 3 versus 2) and more positive axillas (22.7% involved axillas were discovered by fluorescence only) than either method alone. No acute or chronic allergic reaction was observed in this study. However, 23 patients (23/82) who received breast-conserving therapy reported temporary skin staining, and 5 patients had permanent tattooing. Palpable subcutaneous nodules at the injection sites were reported in nine patients. There were no reports of skin necrosis.

CONCLUSIONS

The lymphatic navigation by ICG fluorescence detects SLNs at a high detection rate and improves the mapping performance when added to the MB method. The novel ICG + MB dual tracing modality, without involvement of radioactive isotopes, exhibits great potential as an alternative to traditional standard mapping methods.

TRIAL REGISTRATION

ACTRN12612000109808 . Retrospectively registered on 23 January 2012.

Criteria derived from serum markers can precisely evaluate axillary status in breast cancer patients

BACKGROUND

A noninvasive method to confirm the presence of lymph node metastases (LNM) in breast cancer patients is lacking. This study aimed to identify markers from peripheral blood that have diagnostic value in evaluating axillary LNM.

METHODS

We tested 26 factors in serum from 57 patients with resectable breast cancer by the Luminex assay. Differences between node-negative and node-positive patients were assessed. The diagnostic value of the factors was determined by further analyses and a validation test.

RESULTS

Matrix metalloproteinase-1, hepatocyte growth factor, and chemokine ligand 5 were independent risk factors for LNM. However, receiver operating characteristic analysis showed that these factors alone were not ideal predictors. The LNM score (LNMS), derived from combining these markers, correlated significantly with numbers of positive lymph nodes. Patients with LNMS of 0 had few LNM, axillary lymph node dissection (ALND) could be avoided, and sentinel lymph node biopsy (SLNB) was unnecessary. Very high accuracy was achieved for patients with LNMS of 1 with SLNB using only methylene blue, patients with LNMS of 3 required ALND, and patients with LNMS of 2 needed SLNB using both a radioactive isotope and methylene blue, and ALND.

CONCLUSIONS

The LNMS derived from matrix metalloproteinase-1, hepatocyte growth factor, and chemokine ligand 5 serum levels identified the axillary lymph node status with high accuracy. Patients with higher LNMS had a greater probability of LNM.

The Nordic SentiMag trial: a comparison of super paramagnetic iron oxide (SPIO) nanoparticles versus Tc(99) and patent blue in the detection of sentinel node (SN) in patients with breast cancer and a meta-analysis of earlier studies

The aim of the study is to compare the efficacy of SPIO as a tracer in sentinel node biopsy (SNB) in breast cancer with Tc and patent blue in a multicentre prospective study and perform a meta-analysis of all published studies. It also aims to follow skin discoloration after SPIO injection and describe when and how it resolves. Totally 206 patients with early breast cancer were recruited. Tc and patent blue were administered in standard fashion. Patients were injected with SPIO (Sienna+) preoperatively. SNB was performed and detection rates were recorded for both methods. Skin discoloration was followed and documented postoperatively. Data extraction and subsequent meta-analysis of all previous studies were also performed. SN detection rates were similar between standard technique succeeded and SPIO both per patient (97.1 vs. 97.6 %, p = 0.76) as well as per node (91.3 vs. 93.3 %, p = 0.34), something which was not affected by the presence of malignancy. Concordance rates were also consistently high (98.0 % per patient and 95.9 % per node). Discoloring was present in 35.5 % of patients postoperatively, almost exclusively in breast conservation. It fades slowly and is still detectable in 8.6 % of patients after 15 months. Meta-analysis depicted similar detection rates (p = 0.71) and concordance rates (p = 0.82) per patient. However, it seems that SPIO is characterized by higher nodal retrieval (p < 0.001). SPIO is an effective method for the detection of SN in patients with breast cancer. It is comparable to the standard technique and seems to simplify logistics. Potential skin discoloration is something of consideration in patients planned for breast conservation.

[Acute blue urticaria following subcutaneous injection of patent blue dye]

BACKGROUND

Patent blue (PB) is a lymphatic vessel dye commonly used in France for sentinel lymph node detection in breast cancer, and less frequently in melanoma, and which may induce hypersensitivity reactions. We report a case of acute blue urticaria occurring within minutes of PB injection.

PATIENTS AND METHODS

Ten minutes after PB injection for sentinel lymph node detection during breast cancer surgery, a 49-year-old woman developed generalised acute blue urticaria and eyelid angioedema without bronchospasm or haemodynamic disturbance, but requiring discontinuation of surgery. Skin testing using PB and the anaesthetics given were run 6 weeks after the episode and confirmed PB allergy. PB was formally contra-indicated.

DISCUSSION

Immediate hypersensitivity reactions to PB have been reported for between 0.24 and 2.2% of procedures. Such reactions are on occasion severe, chiefly involving anaphylactic shock. Two mechanisms are probably associated: non-specific histamine release and/or an IgE-mediated mechanism. Skin tests are helpful in confirming the diagnosis of PB allergy.

CONCLUSION

Blue acute urticaria is one of the clinical manifestations of immediate hypersensitivity reactions to patent blue dye. Skin tests must be performed 6 weeks after the reaction in order to confirm the diagnosis and formally contra-indicate this substance.

The superparamagnetic iron oxide is equivalent to the Tc99 radiotracer method for identifying the sentinel lymph node in breast cancer

BACKGROUND

Preoperative injection of Tc99 is standardly performed before sentinel lymph node biopsy (SLN) for breast cancer. Multiple questions have arisen concerning appropriate technique for SLNBs including site of injection, timing and injection material. The aim of this study was to assess the concordance between a new method, superparamagnetic iron oxide (SPIO) and the Tc99 radiotracer to identify the SLN in early breast cancer.

MATERIAL AND METHODS

Between July 2013 and March 2014, 120 patients with clinically node negative early breast cancer were included in the study. Patients were injected the day before the radiotracer for lymphoscintigraphy and injected the SPIO subareolar intraoperatively. SLN was excised if it was radioactive, magnetic or palpable. Patients signed an inform consent.

RESULTS

There was no drainage by either technique in 2 patients, so this leaves 118 patients for further analysis. Detection rate by Tc 99 was successful in 113 (95.7%%) patients and by SPIO in 116 (98.3%). Concordance rates per patient between techniques was 98.2%. The SLN was positive in 36 (30%) patients. Of this, SLN positivity was detected by both techniques in 32 patients. Mean number of SLNs by 99Tc and SPIO were 1.9 and 2.21 respectively (p = 0.001).

DISCUSSION

Detection of SLNs with SPIO allows for easy identification of axillary nodes, at a frequency not inferior to the radiotracer. It is an oncologically safe procedure, facilitates patients and operative room management and can be used to reliably identify SLNs in breast cancer.