Methylene blue dye--a safe and effective alternative for sentinel lymph node localization

Blue Wheals and Blue Angioedema Induced by Blue Dyes: A Systematic Review

BACKGROUND

Blue wheals and blue angioedema, the adverse reactions to blue dye injections with or without anaphylaxis, are poorly defined.

OBJECTIVE

The objective is to review the characteristics (ie, sex and age at onset, interval between blue dye injection and symptom onset, clinical manifestations, duration of blue wheals or angioedema), natural courses, and treatments of blue dye adverse reactions.

METHODS

A review of the articles published through July 2021 was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations.

RESULTS

Across 523 patients (175 studies) with any adverse reactions to blue dye injections, wheals, angioedema, or both occurred in 193 patients (36.9%). Of these 193 patients, 68 patients (35.2%) developed blue wheals or angioedema, 118 (61.1%) had ordinary wheals or angioedema (nonbluish), and 7 had both (3.6%). We reviewed 169 patients with available data (99 with ordinary lesions and 70 with blue lesions). Patent blue violet had the highest rate of inducing blue wheals or angioedema (odds ratio 4.9). Almost half of the patients with blue wheals or angioedema developed systemic symptoms; and of those with systemic symptoms, all except 1 progressed to anaphylaxis. On-demand treatments with antihistamines, corticosteroids, and epinephrine were commonly used and effective.

CONCLUSIONS

Using blue dyes can lead to blue wheals or angioedema and systemic reactions. In patients with a history of a severe allergic reaction to a blue dye, repeat administration of a blue dye should be used only after carefully weighing all the risks and benefits.

Application of indocyanine green lymphography combined with methylene blue staining in lymphaticovenular anastomosis of lower limb vessels: A prospective study

BACKGROUND

Methylene blue (MB) is a conventional lymphatic tracer. We evaluated the application of indocyanine green (ICG) lymphography combined with MB staining in lower limb lymphaticovenular anastomosis (LVA).

METHODS

A total of 49 patients with lower limb lymphedema were selected as the study subjects and divided into the research (n = 27) and control groups (n = 22). The patients were treated with LVA using ICG lymphography combined with MB staining and simple ICG lymphography as the positioning method, respectively. The number of lymphatic vessels anastomosed and the operating time were compared between the groups. Lower Extremity Lymphedema Index (LEL index) and Lymphoedema Functioning, Disability and Health Questionnaire for Lower Limb Lymphoedema (Lymph-ICF-LL) were used as prognostic indices; 6 months after LVA, both groups were evaluated for the symptomatic relief of lymphedema.

RESULTS

The number of anastomotic lymphatic vessels in the study group was higher than that in the control group (p < .05), and their procedural time was shorter than that in the control group. The two groups had no significant difference in lymphatic anastomosis time (p > .05). The LEL index and Lymph-ICF-LL of the research and control groups at 6-month follow-up after LVA were lower than those before the operation (p < .05).

CONCLUSION

The circumference of the affected limb is reduced after LVA in patients with lower extremity lymphedema with a favorable prognosis. ICG lymphography combined with MB staining has the advantages of real-time visualization and accurate localization.

Test method for evaluating the photocytotoxic potential of fluorescence imaging products

Various fluorescence imaging agents are currently under clinical studies. Despite significant benefits, phototoxicity is a barrier to the clinical translation of fluorophores. Current regulatory guidelines on medication-based phototoxicity focus on skin effects during sun exposure. However, with systemic and local administration of fluorophores and targeted illumination, there is now possibility of photochemical damage to deeper tissues during intraoperative imaging procedures. Hence, independent knowledge regarding phototoxicity is required to facilitate the development of fluorescence imaging products. Previously, we studied a cell-free assay for initial screening of reactive molecular species generation from fluorophores. The current work addresses a safety test method based on cell viability as an adjunct and a comparator with the cell-free assay. Our goal is to modify and implement an approach based on the in vitro 3T3 neutral red uptake assay of the Organization for Economic Co-Operation and Development Test Guideline 432 (OECD TG432) to evaluate the photocytotoxicity of clinically relevant fluorophores. These included indocyanine green (ICG), proflavine, methylene blue (MB), and IRDye800, as well as control photosensitizers, benzoporphyrin derivative (BPD) and rose bengal (RB). We performed measurements at agent concentrations and illumination parameters used for clinic imaging. Our results aligned with prior studies, indicating photocytotoxicity in RB and BPD and an absence of reactivity for ICG and IRDye800. DNA interactive agents, proflavine and MB, exhibited drug/light dose-response curves like photosensitizers. This study provides evidence and insights into practices useful for testing the photochemical safety of fluorescence imaging products.

Translational Potential of Fluorescence Polarization for Breast Cancer Cytopathology

Breast cancer is the most common malignancy in women. The standard of care for diagnosis involves invasive core needle biopsy followed by time-consuming histopathological evaluation. A rapid, accurate, and minimally invasive method to diagnose breast cancer would be invaluable. Therefore, this clinical study investigated the fluorescence polarization (Fpol) of the cytological stain methylene blue (MB) for the quantitative detection of breast cancer in fine needle aspiration (FNA) specimens. Cancerous, benign, and normal cells were aspirated from excess breast tissues immediately following surgery. The cells were stained in aqueous MB solution (0.05 mg/mL) and imaged using multimodal confocal microscopy. The system provided MB Fpol and fluorescence emission images of the cells. Results from optical imaging were compared to clinical histopathology. In total, we imaged and analyzed 3808 cells from 44 breast FNAs. Fpol images displayed quantitative contrast between cancerous and noncancerous cells, whereas fluorescence emission images showed the morphological features comparable to cytology. Statistical analysis demonstrated that MB Fpol is significantly higher (p < 0.0001) in malignant vs. benign/normal cells. It also revealed a correlation between MB Fpol values and tumor grade. The results indicate that MB Fpol could provide a reliable, quantitative diagnostic marker for breast cancer at the cellular level.

Tracers in Gastric Cancer Surgery

The treatment of gastric cancer mainly depends on radical gastrectomy. Determination of appropriate surgical margins and adequate lymph node (LN) resection are two major surgical steps that directly correlate with prognosis in gastric cancer. Due to the expanding use of minimally invasive procedures, it is no longer possible to locate tumors and LNs through touch. As an alternative, tracers have begun to enter the field due to their capacities for intraoperative visualization. Herein, we summarize the application of contemporary tracers in gastric cancer surgery, including isosulfan blue, methylene blue, patent blue, indocyanine green, carbon particles, and radioactive tracers. Their mechanisms, administration methods, detection efficiency, and challenges, as well as perspectives on them, are also outlined.

Comparing single or dual tracing modality on sentinel lymph node biopsy from patients who plan to omitting axillary lymph node dissection referring to the criteria of Z0011 trial: a retrospective study

Axillary lymph node dissection (ALND) can be omitted in the part of the breast-conserving patients with positive sentinel lymph nodes (SLNs) since Z0011 trial has presented. Nevertheless, to date, no studies revealed the influence of different tracing modalities (single tracer versus dual tracers) for sentinel lymph node biopsy (SLNB) on axillary management referring to Z0011 trial criteria. This study aimed to assess whether different tracing modalities of SLNB have impact on axillary management referring to Z0011 trial criteria. The clinical data of breast-conserving patients who underwent SLNB guided by combination of methylene blue (MB) and indocyanine green(ICG) were retrospectively analyzed in our center. The numbers of metastatic (positive) SLNs guided by the single tracer and the dual tracer were compared by self-control study. 127 patients with 1-2 metastatic SLNs dyed by MB [(recorded as MB(+))]were retrieved from our database between 2016 and 2020. In these cases, 53 patients contained 86 SLNs, which were ICG staining but MB negative staining (recorded as ICG(+)/MB(-)). In addition, 16 patients contained 20 metastatic SLNs with ICG(+)/MB(-). There were six patients finally excluded patients (6/127, 4.7%) who initially met the criteria of Z0011 trial, because the further detection of ICG(+)/MB(-) SLNs led the total numbers of positive SLNs over two. The difference was statistically significant. Single tracing modality may underestimate the positive SLN numbers compared to dual tracing modality. Different tracing modalities of SLNB will significantly affect Axillary management referring to Z0011 trial criteria.

Fluorescence Polarization Imaging of Methylene Blue Facilitates Quantitative Detection of Thyroid Cancer in Single Cells

Simple Summary

Accurate diagnosis of thyroid fine-needle aspiration cytology is a significant clinical challenge. A method to detect thyroid cancer at the cellular level would be invaluable to reduce diagnostic uncertainty and improve clinical decision making. We studied the ability of confocal fluorescence polarization imaging of an exogenous fluorophore, methylene blue, to provide quantitative discrimination of cancerous cells in human samples. Our results indicate that fluorescence polarization imaging provides a reliable biomarker of thyroid cancer and holds the potential to shift the paradigm of cellular level cancer diagnosis from subjective visual assessment to objective measurement.

Abstract

Background: Diagnostic accuracy of the standard of care fine-needle aspiration cytology (FNAC) remains a significant problem in thyroid oncology. Therefore, a robust and accurate method for reducing uncertainty of cytopathological evaluation would be invaluable. Methods: In this double-blind study, we employed fluorescence emission and quantitative fluorescence polarization (Fpol) confocal imaging for sorting thyroid cells into benign/malignant categories. Samples were collected from malignant tumors, benign nodules, and normal thyroid epithelial tissues. Results: A total of 32 samples, including 12 from cytologically indeterminate categories, were stained using aqueous methylene blue (MB) solution, imaged, and analyzed. Fluorescence emission images yielded diagnostically relevant information on cytomorphology. Significantly higher MB Fpol was measured in thyroid cancer as compared to benign and normal cells. The results obtained from 12 indeterminate samples revealed that MB Fpol accurately differentiated benign and malignant thyroid nodules. Conclusions: The developed imaging approach holds the potential to provide an accurate and objective biomarker for thyroid cancer, improve diagnostic accuracy of cytopathology, and decrease the number of lobectomy and near-total thyroidectomy procedures.

Sentinel lymph node detection by combining nonradioactive techniques with contrast agents: State of the art and prospects

The status of sentinel lymph nodes (SLNs) has a substantial prognostic value because these nodes are the first place where cancer cells accumulate along their spreading route. Routine SLN biopsy ("gold standard") involves peritumoral injections of radiopharmaceuticals, such as technetium-99m, which has obvious disadvantages. This review examines the methods used as "gold standard" analogs to diagnose SLNs. Nonradioactive preoperative and intraoperative methods of SLN detection are analyzed. Promising photonic tools for SLNs detection are reviewed, including NIR-I/NIR-II fluorescence imaging, photoswitching dyes for SLN detection, in vivo photoacoustic detection, imaging and biopsy of SLNs. Also are discussed methods of SLN detection by magnetic resonance imaging, ultrasonic imaging systems including as combined with photoacoustic imaging, and methods based on the magnetometer-aided detection of superparamagnetic nanoparticles. The advantages and disadvantages of nonradioactive SLN-detection methods are shown. The review concludes with prospects for the use of conservative diagnostic methods in combination with photonic tools.

Quantitative and Semi-quantitative Methods for Assessing the Degree of Methylene Blue Staining in Sentinel Lymph Nodes in Dogs

Background: To develop a digital algorithm for quantitative assessment of surface methylene blue staining in whole lymph nodes and validate a semi-quantitative visual scoring method for patient-side use.

Methods: Lymph nodes from canine patients with spontaneous tumors undergoing sentinel lymph node mapping were prospectively assessed ex vivo and photographed. Using an open-source computer-based imaging software, an algorithm was developed for quantification of staining based on a signal-to-background ratio. Next, two blinded observers evaluated images and assigned a semi-quantitative visual score based on surface staining (0—no blue stain, 1−1–50% stained, and 2−51–100% stained) and those results were compared to the established quantitative standard.

Results: Forty-three lymph nodes were included. Image analysis successfully quantified blue staining and differentiated from normal lymph node tissue in all cases. Agreement between observers using the Kappa coefficient demonstrated strong agreement (k = 0.8581, p < 0.0001) between semi-quantitative visual scoring and image analysis. There was substantial interobserver and intraobserver agreement for the scoring system (k = 0.7340, p < 0.0001 and k = 0.8983, p < 0.0001, respectively).

Conclusion: A digital algorithm using an open-source software was simple and straightforward to use for quantification of blue staining. The use of a semi-quantitative visual scoring system shows promise for a simple, objective, repeatable assessment of methylene blue staining at the time of surgery. This study demonstrates reliable and repeatable methods for blue staining quantification thereby providing a novel and objective reporting mechanism in scientific research involving sentinel lymph node mapping.

Clipping inguinal lymphatics decreases lymphorrhoea after lymphadenectomy following cancer treatment: results from a randomized clinical trial

BACKGROUND

Post-operative lymphorrhea is a well-known complication of inguinal lymph node dissection. However, the interventions to reduce the duration of drain in situ have not been sufficiently elaborated.

OBJECTIVES

We evaluated the potential role of intra-operative mapping of lymphatic leakage with peri-incisional methylene blue injection and clipping of lymphatics after inguinal block dissection in reducing postoperative lymphorrhea.

METHODS

We randomized 39 inguinal dissections done for various malignancies such as for carcinoma penis, urethra, malignant melanoma, rectum into 19 dissections (Interventional group) and 20 dissections (Control group). In the interventional group, after the completion of inguinal dissection, two ml of methylene blue dye was injected 4-8cm from the incision to identify the leaking lymphatics and they were clipped.

RESULTS

The primary outcome was the decrease in duration of days of drain in situ and was found to have significant reduction of 3.07 days in the interventional arm. (p value-0.02). The secondary outcome was the reduction of 21 ml of mean drain output in the interventional group (p = 0.09). The number of lymphatics clipped was not found to have statistical correlation with the duration of drain in situ and the mean drain output.

CONCLUSION

The intraoperative mapping of lymphatic channels using methylene blue after inguinal dissection reduces the number of days of drain in situ.

Fluorescence Guided Surgery

Fluorescence guided surgery (FGS) is an imaging technique that allows the surgeon to visualise different structures and types of tissue during a surgical procedure that may not be as visible under white light conditions. Due to the many potential advantages of fluorescence guided surgery compared to more traditional clinical imaging techniques such as its higher contrast and sensitivity, less subjective use, and ease of instrument operation, the research interest in fluorescence guided surgery continues to grow over various key aspects such as fluorescent probe development and surgical system development as well as its potential clinical applications. This review looks to summarise some of the emerging opportunities and developments that have already been made in fluorescence guided surgery in recent years while highlighting its advantages as well as limitations that need to be overcome in order to utilise the full potential of fluorescence within the surgical environment.

Near-infrared laparoscopy with indocyanine green for axillary sentinel lymph node biopsy in early breast cancer: preliminary experience of a single unit

Background

A sentinel lymph node biopsy (SLNB) is a routine procedure for axillary staging in cN0 breast cancer (BC) patients. Indocyanine green (ICG) fluorescence can detect sentinel lymph nodes with higher sensitivity than carbon nanoparticle suspension (CNS). The present study investigated the availability and benefits of a near-infrared (NIR) laparoscopy-assisted SLNB using ICG and carbon nanoparticle suspension as tracers.

Methods

Forty patients with invasive BC, who had clinically negative axillary lymph nodes, participated in this observational study. ICG and CNS tracers were injected into the periareolar region simultaneously or sequentially. In the endoscopy-assisted group (n=20), the patients were given NIR laparoscopic SLNB based on ICG fluorescence and CNS staining. In the open-surgery group, the patients were given traditional SLNB using an open incision, and CNS tracers were injected into the same region as that in the endoscopy-assisted group.

Results

In the endoscopy-assisted group, lymphatic vessels and sentinel lymph nodes (SLNs) were successfully identified using ICG fluorescence imaging in most patients (19/20). The average number of SLNs removed was 2.85 (range, 1-4) in the endoscopy-assisted group, and 3.40 (range, 1-7) in the open-surgery group. There was no significant difference between the number of detected nodes (P=0.30). The patients who underwent endoscopy-assisted SLNBs had similar operating times, blood loss and hospital-stay lengths, but lower postoperative drainage volumes and higher satisfaction scores, as they did not have axillary incisions.

Conclusions

The NIR laparoscopy-assisted ICG-guided technique is a feasible and surgeon-friendly method for SLNB with good efficacy and acceptable safety. When combined with CNS, more SLNs can be detected and dissected.

Sentinel Lymph Node Biopsy in Early Breast Cancer Using Methylene Blue Dye Alone: a Safe, Simple, and Cost-Effective Procedure in Resource-Constrained Settings

Sentinel lymph node biopsy (SLNB) is done by different techniques in clinically node-negative patients with early breast cancer. In this study, we aim to estimate the identification rates, positivity rates, cost-effectiveness, and outcomes for patients who underwent sentinel node biopsy using methylene blue dye alone. This was a retrospective review of 172 patients with early breast cancer (cT1-3, N0) who underwent SLNB using methylene blue dye alone between January 2014 and December 2018 including their follow-up details until December 2019. The mean age was 51 ± 10.3 (range: 28 to 76) years. There were 63 (36.6%) patients with cT1 tumor, 108 (62.7%) with cT2, and only 1 patient with cT3 tumor. Breast conservation surgery was performed in 62 (36%) while the remaining 110 (64%) underwent simple mastectomy. Sentinel nodes were successfully identified in 165 (95.9%) with a positivity rate of 23.6%. There was no dye-related adverse reactions intra-operatively. The mean duration of follow-up was 26.68 ± 15.9 months (range: 1-60). Chronic arm pain was present in 7 (4%) while none of the patients had lymphedema or restriction of shoulder joint motion. There were no documented axillary nodal recurrences in this cohort. Eight (4.65%) patients were detected to have systemic metastasis. One patient died of brain metastasis from bilateral breast cancer. The mean disease-free survival was 57 months (95% CI: 55-59). Sentinel lymph node biopsy using methylene dye alone is a safe, simple, and cost-effective alternative to isosulfan blue or radio isotope technique in surgical centers with resource constraints.

Methylene Blue-Current Knowledge, Fluorescent Properties, and Its Future Use

Methylene blue is a fluorescent dye discovered in 1876 and has since been used in different scientific fields. Only recently has methylene blue been used for intraoperative fluorescent imaging. Here, the authors review the emerging role of methylene blue, not only as a dye used in clinical practice, but also as a fluorophore in a surgical setting. We discuss the promising potential of methylene blue together with the challenges and limitations among specific surgical techniques. A literature review of PubMed and Medline was conducted based on the historical, current and future usage of methylene blue within the field of medicine. We reviewed not only the current usage of methylene blue, but we also tried to grasp its’ function as a fluorophore in five main domains. These domains include the near-infrared imaging visualization of ureters, parathyroid gland identification, pancreatic tumors imaging, detection of breast cancer tumor margins, as well as breast cancer sentinel node biopsy. Methylene blue is used in countless clinical procedures with a relatively low risk for patients. Usage of its fluorescent properties is still at an early stage and more pre-clinical, as well as clinical research, must be performed to fully understand its potentials and limitations.

Sentinel lymph node biopsy for breast cancer using methylene blue: a new anatomical landmark involving intercostobrachial and medial pectoral nodes

BACKGROUND Sentinel lymph node biopsy (SLNB) using blue dye is becoming popular in Indonesia given that knowledge on new anatomical landmarks involving intercostobrachial and medial pectoral nodes have replaced the need for radioisotope tracers. This study aimed to evaluate the utility of the proposed landmark involving intercostobrachial and medial pectoral nodes to determine axillary lymph node status during SLNB. METHODS A prospective study was conducted involving 55 patients with early-stage breast cancer who had clinically negative lymph nodes (T1–T2, cN0) between 2018 and 2019 at Cipto Mangunkusumo Hospital. During SLNB, methylene blue 1% was injected at the subareolar area to identify intercostobrachial and medial pectoral nodes followed by axillary lymph node dissection (ALND). Histopathological results of sentinel nodes (SNs) were then compared to those of other axillary nodes. RESULTS SNs were identified in 54 patients (98%), 33 (61%) of whom had both intercostobrachial and medial pectoral SNs. Among patients with SNs, there were 1 patient without intercostobrachial SNs, 10 patients without medial pectoral SNs, and 1 patient with medial pectoral SNs but no intercostobrachial SNs. Accordingly, SNs had a negative predictive value (NPV) of 96.77% for axillary metastasis (95% confidence interval = 81.54–99.51), with a false negative rate of 4.7%. No serious adverse events was observed. CONCLUSIONS The high identification rate and NPV, as well as the low false negative rate of the new anatomical landmark involving intercostobrachial and medial pectoral nodes during SLNB, suggest its reliability in determining axillary lymph node status.

Current trends in pyrrole and porphyrin-derived nanoscale materials for biomedical applications

This article is written to provide an up-to-date review of pyrrole-based biomedical materials. Porphyrins and other tetrapyrrolic molecules possess unique magnetic, optical and other photophysical properties that make them useful for bioimaging and therapy. This review touches briefly on some of the synthetic strategies to obtain porphyrin- and tetrapyrrole-based nanoparticles, as well as the variety of applications in which crosslinked, self-assembled, porphyrin-coated and other nanoparticles are utilized. We explore examples of these nanoparticles' applications in photothermal therapy, drug delivery, photodynamic therapy, stimuli response, fluorescence imaging, photoacoustic imaging, magnetic resonance imaging, computed tomography and positron emission tomography. We anticipate that this review will provide a comprehensive summary of pyrrole-derived nanoparticles and provide a guideline for their further development.

Novel technique to manage refractory chylous ascites with carbon nanoparticle suspension in infants

OBJECTIVE

Chylous ascites (CA) is a rare form of ascites that results from the leakage of lipid-rich lymph into the peritoneal cavity. In infants, CA is mostly caused by lymphatic malformation or unknown reasons. The creation of a shunt for the lymphorrhea is the last option for patients unresponsive to all other conservative treatments. Localization of the leakage is a critical problem during surgery. We applied a carbon nanoparticle suspension (CNS) in CA patients to locate the external lymphatic leakage and evaluated its utility during surgery.

PATIENTS AND METHODS

Twelve infants with CA were treated in our center recently. Ten patients received laparotomy, one refused therapy, and one was cured after undergoing conservative treatment. Recently, two infants with CA received CNS in the visceral peritoneum during laparotomy. The results of the traditional procedure were compared to our innovative technique for CA to evaluate the use of CNS in treating CA.

RESULTS

The features of the baseline data did not differ substantially. Location of the leakage with CNS was employed in 2 of the 10 patients whose lymphatic leakages were identified with the resolution of the refractory CA. Overall, in 5 patients, ascites was resolved successfully. The refractory CA was resolved more effectively in patients in whom the leakage site was identified with CNS than in patients in whom the leakage site could not be identified under conventional surgery.

CONCLUSIONS

Injecting CNS improved the accuracy of lymphorrhagia leakage site identification and the outcomes of infants who underwent surgical treatment for refractory CA.

LEVEL OF EVIDENCE

II-III.

How Pre-operative Sentinel Lymph Node Contrast-Enhanced Ultrasound Helps Intra-operative Sentinel Lymph Node Biopsy in Breast Cancer: Initial Experience

We aimed to evaluate the value of sentinel lymph node contrast-enhanced ultrasound (SLN-CEUS) and surface tracing for the biopsy of intra-operative sentinel lymph nodes (SLNs). Between June 2015 and December 2017, a total of 453 patients with early invasive breast cancer were recruited. Patients received an intradermal injection of microbubble contrast agent around the areola on the day before surgery. The locations and sizes of lymphatic channels (LCs) and SLNs were marked on the body surface using gentian violet. Then, injection of double blue dye was performed half an hour before surgery. We compared the pathway of LCs and the location of SLNs obtained from SLN-CEUS and blue dye during surgery. Among the 453 patients, the mean numbers of LCs and SLNs detected by SLN-CEUS were 1.42 and 1.72, respectively, and the coincidence rate was 98.2% compared with blue dye during surgery. The median distance from the SLN to skin measured by pre-operative CEUS and blue dye was 1.95 ± 0.69 and 2.03 ± 0.87 cm (p = 0.35). There were three SLN enhancement in our research, including homogeneous enhancement, inhomogeneous enhancement and no enhancement, with the sensitivity, specificity, positive predictive value and negative predictive value of SLN-CEUS for the diagnosis of SLNs being 96.82%, 91.91%, 87.54% and 98.01%, respectively. SLN-CEUS with skin marking can identify the pathway of LCs and the location of the SLN before surgery, measure the distance from the SLN to skin and determine if the SLN is metastatic. SLN-CEUS can be used as an effective complement to the blue dye method.

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.

Application of a carbon nanoparticle suspension for sentinel lymph node mapping in patients with early breast cancer: a retrospective cohort study

BACKGROUND

To stage axillary lymph nodes in women with early-stage breast cancer, sentinel lymph node biopsy (SLNB), rather than axillary lymph node dissection (ALND), has been employed. Moreover, different tracer methods have various advantages and disadvantages. In recent years, carbon nanoparticle suspensions (CNSs) have been used as lymph node tracers during surgeries for thyroid cancer, gastric cancer, and colorectal cancer. The study retrospectively analyzed the feasibility and accuracy of CNS for sentinel lymph node (SLN) mapping in patients with early breast cancer.

METHODS

This single-center, retrospective study included breast cancer patients who underwent SLNB from January 1, 2016, to December 31, 2017, in the Department of Breast Cancer, Guangdong General Hospital. All patients received standard SLNB surgery using a CNS tracer.

RESULTS

A total of 332 cases were included in this study. The SLN identification rate was 99.1% (329/332), and the mean number of SLNs was 2.6 (range, 1-6). SLN metastasis was found in 62 (18.8%) cases, of which 90.3% were found to be macrometastases. The sensitivity of SLNB was 95.9% (47/49), with a specificity of 100% (42/42), a positive predictive value of 100% (47/47), a negative predictive value of 95.5% (42/44), and a false-negative rate of 4.1% (2/49).

CONCLUSION

The identification and predictive values of a CNS tracer for SLNB were satisfactory.

Individual marking of soft-bodied subtidal invertebrates in situ - A novel staining technique applied to the giant plumose anemone Metridium farcimen (Tilesius, 1809)

The ability to recognize individuals and track growth over time is crucial to population dynamics research as well as studies of animal behavior. Invertebrates are particularly difficult to track as they often molt, have regenerative capabilities, or lack hard parts to attach markers. We tested, in laboratory and field studies, a new way of marking sea anemones (order Actiniaria) by injection of three vital stains (i.e., neutral red, methylene blue, and fluorescein). Neutral red and methylene blue did not affect growth or survival, but fluorescein was lethal at high concentrations. Marked individuals could be identified up to seven months after injection with neutral red, six weeks with methylene blue, and three days with low concentrations of fluorescein. Neutral red could be used for long-term monitoring of growth and survival in the field, and in combination with methylene blue could be used to mark individuals in distinguishable patterns for short-term studies such as examining predator-prey interactions, movement of individuals, and recruitment survival.

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.

A prospective randomized trial comparing patent blue and methylene blue for the detection of the sentinel lymph node in breast cancer patients

Introduction:

Methylene blue is more widely available and less expensive than patent blue, with an apparently lower risk of anaphylaxis.

Objective:

The two dyes were compared regarding detection of the sentinel lymph node (SLN).

Method:

A prospective, randomized trial involved 142 patients with invasive breast carcinoma. Sixty-nine (49.3%) assigned to patent blue (group A) and 71 (50.70%) to methylene blue (group B). Thirty-five patients (25.0%) were clinical stage III or IV; 55 (38.7%) had axillary lymph nodes affected; and 69 (49.3%) underwent neoadjuvant chemotherapy. Two patients were excluded because the dye type was not recorded.

Results:

Patients and tumor characteristics were similar in both groups. SLNs were identified in 47 women (68.1%) in group A and 43 (60.6%) in group B (p=0.35). SLNs were affected in 22 cases (51.2%) in group A and 21 (48.8%) in group B (p=0.62). The SLN was the only node affected in 12 cases (54.5%) in group A and six (33.3%) in group B (p=0.18). The time and degree of difficulty involved in identifying the SLN were similar in both groups. There were no complications or allergies.

Conclusion:

Methylene blue performed as well as patent blue in identifying the SLN in breast cancer patients.

Sentinel lymph node mapping in endometrial cancer: comparison of fluorescence dye with traditional radiocolloid and blue

Sentinel lymph node (SLN) mapping in endometrial cancer (EMCA) is rapidly gaining acceptance in the clinical community. As compared to a full lymphadenectomy in every patient, to a selective lymphadenectomy after frozen section of uterus in selected patients with intrauterine risk factors or to a strategy in which a lymphadenectomy is always omitted, SLN mapping seems to be a reasonable and oncologically safe middle ground. Various protocols can be used when applying an SLN mapping. In this manuscript we review the characteristics, toxicity and clinical impact of technetium-99m radiocolloid (Tc-99m), of the blue dyes (methylene blue, isosulfan blue and patent blue) and of indocyanine green (ICG). ICG has an excellent toxicity profile, has higher overall and bilateral detection rates as compared to blue dyes and higher bilateral detection rates as compared to a combination of Tc-99m and blue dye. The detrimental effect of BMI on the detection rates is attenuated when ICG is used as a tracer. The ease of use of the ICG SLN mapping is perceived by the patients as a better quality of care delivered. Whenever possible, ICG should be favored over the other tracers for SLN mapping in EMCA patients.

Breast Cancer Sentinel Node Detection: An Alternative Solution for Centers Lacking Nuclear Technology

BACKGROUND

Sentinel lymph node (SLN) has become the gold standard for all cases with no axillary nodal metastasis. The combined radioisotope and blue dye technique is adopted in most centers. The lack of the technology for radioisotope in our institution encouraged us to study the feasibility of methylene blue (MB) for SLN detection in breast cancer patients admitted to Alexandria Surgical Oncology Unit.

METHODS

A total of 144 cases were subjected to SLN detection by injecting 2 ml of MB 1%. This was followed by standard axillary lymph node dissection. The safety and accuracy of MB as a tracer for detection of SLN were studied.

RESULTS

The identification rate was 93.15%. The number of SLN identified ranged from 1 to 8 nodes with a mean of 1.75 ± 1.17. The sensitivity of MB dye technique was 96.3%. The false negative rate was 3.7%. The negative predictive value was 97.6% and the accuracy was 98.5%.

CONCLUSIONS

MB is a safe, reliable, cheap, and accurate alternative tracer for detection of SLN.

Experimental Study of Magnetic Multi-Walled Carbon Nanotube-Doxorubicin Conjugate in a Lymph Node Metastatic Model of Breast Cancer

BACKGROUND The lymphatic system plays a significant role in the defense of a subject against breast cancer and is one of the major pathways for the metastasis of breast cancer. To improve the prognosis, many means, including surgery, radiotherapy, and chemotherapy, have been used. However, the combination of all these modalities has limited efficacy. Lymph nodes, therefore, have become an exceptionally potential target organ in cancer chemotherapy. MATERIAL AND METHODS A lymph node metastatic model of breast cancer was established in BALB/c mice. Magnetic multi-walled carbon nanotube carrier with good adsorption and lymph node-targeting capacity was prepared and conjugated with doxorubicin to make the magnetic multi-walled carbon nanotube-doxorubicin suspension. Dispersions of doxorubicin, magnetic multi-walled carbon nanotube-doxorubicin, and magnetic multi-walled carbon nanotube were injected into lymph node metastatic mice to compare their inhibitory effects on tumor cells in vivo. Inhibition of these dispersions on EMT-6 breast cancer cells was detected via MTT assay in vitro. RESULTS Although no significant difference was found between the effects of doxorubicin and magnetic multi-walled carbon nanotube-doxorubicin with the same concentration of doxorubicin on EMT-6 breast cancer cells in vitro, in terms of sizes of metastatic lymph nodes and xenograft tumors, apoptosis in metastatic lymph nodes, and adverse reactions, the magnetic multi-walled carbon nanotube-doxorubicin group differed significantly from the other groups. CONCLUSIONS The magnetic multi-walled carbon nanotube-doxorubicin clearly played an inhibitory role in lymph node metastases to EMT-6 breast cancer cells.

Manual Lymphatic Drainage after Subepidermal Tracer Injection Optimizes Results of Sentinel Lymph Node Labeling in Primary Breast Cancer

INTRODUCTION

Our aim was to assess the practicability and reliability of a novel labeling regime for axillary sentinel lymph nodes (SLNs) in early breast cancer.

METHODS

362 patients with early breast cancer (bilateral in 9 cases, giving a total of 371 cases) underwent intradermal radio tracer injection with simultaneous manual lymphatic drainage. SLN biopsy was performed within 24 h. For retrospective analysis, data were extracted from patient's records.

RESULTS

At least 1 SLN was detected intraoperatively in 369 cases (99.5%, range 1-9 nodes). This node was metastatic in 88 and unaffected in 281 cases. Coincidentally removed but unlabeled lymph nodes were affected in 3 cases in which the SLN was unaffected (3/153 = 2%). In all cases, on histological evaluation, tissue removed as SLN contained lymph nodes. After a period of 69.5 months (median 1.7-115.8 months), no axillary recurrences were observed in 213 patients.

CONCLUSION

Manual lymphatic drainage is a simple technique that leads to an extremely high pick-up rate of axillary SLNs after subepidermal radio tracer injection. If unaffected, this node correctly predicts nodal-negative disease in 98% of cases studied.

Methylene blue staining in the parotid surgery: Randomized trial, 144 patients

OBJECTIVE

To investigate usefulness of the methylene blue staining for parotid gland surgery.

STUDY DESIGN

Randomized, prospective controlled trial.

METHODS

The study analyzed 144 surgical operations (2000-2014) for parotidectomy. The cases were randomly divided into two groups: Group 1 (n=70) for surgeries with methylene blue staining, and Group 2 (n=74) for surgeries without staining. Surgical complications like temporary facial weakness, permanent facial nerve injury, and Frey's syndrome were taken for comparison between groups as well as rate of tumor recurrence.

RESULTS

Temporary facial weakness and Frey's syndrome occurred almost evenly in both groups (p=0.34, p=0.68 respectively). Permanent facial nerve injury was significantly lower in the group with staining (p=0.032) and the decline of rate of tumor recurrence was even more significant (p=0.007).

CONCLUSION

Intravital staining with methylene blue in parotidectomies simplifies the operation and could assist in better visualization that leads to (1) rapid and precise localization of the tumor, (2) preservation of the facial nerve, and (3) complete removal of the gland tissue in cases with malignancy. This technique reduces the rate of recurrence in cases with malignant tumors.

LEVEL OF EVIDENCE

1.

Improved false negative rate of axillary status using sentinel lymph node biopsy and ultrasound-suspicious lymph node sampling in patients with early breast cancer

Background

The false negative rate of sentinel lymph node biopsy (SLNB) is 5-10%, and results in improper patient management. The study was to assess the value of ultrasound-suspicious axillary lymph node biopsy (USALNB) in patients with early breast cancer, and to compare SLNB combined with USALNB (SLNB + USALNB) with SLNB alone.

Methods

From January 2010 to July 2013, 216 patients with early breast cancer were enrolled consecutively at the Department of Breast and Thyroid Surgery, Qianfoshan Hospital, Shandong University. All patients underwent wire localization of the suspicious node by color Doppler ultrasonography, followed by SLNB 2–3 hours later, suspicious node lymphadenectomy, and level ≥ II axillary dissection (as the gold standard). The predictive values of node status between SLNB + USALNB and SLNB alone were compared.

Results

The success rate of SLNB was 99.1% (214/216). After axillary dissection, 71 patients were confirmed with axillary lymph node metastases by pathological examinations. Eight false negatives were observed using SLNB alone, resulting in sensitivity of 88.7%, specificity of 100%, false negative rate of 11.3%, and false positive rate of 0% in predicting the axillary node status. SLNB + USALNB resulted in sensitivity of 97.2%, specificity of 100%, false negative rate of 2.8%, and false positive rate of 0%. The false negative rate of SLNB + USALNB was significantly different from that of SLNB alone (P = 0.031).

Conclusions

SLNB + USALNB seems to be a low-risk procedure that might be useful in reducing the false negative rate of SLNB, improving the accuracy of axillary nodes evaluation in early breast cancer.

Comparing indocyanine green, technetium, and blue dye for sentinel lymph node mapping in endometrial cancer

BACKGROUND AND AIMS

With the debate over extent of lymphadenectomy in endometrial cancer, sentinel lymph node (SLN) mapping may provide a focused approach to evaluate the most relevant lymph nodes (LN) while minimizing the complications. We evaluated SLN mapping using filtered technetium(99), indocyanine green (ICG), and blue dye.

METHODS

Prospective evaluation of 100 patients who underwent SLN mapping by using submucosal and deep stromal cervical injections of technetium(99), ICG, and blue dye as part of the staging for endometrial cancer.

RESULTS

286 SLNs were mapped (2.9 per patient) in 92% of patients. The bilateral detection rate was 76%. ICG had a significantly higher SLN detection rate than blue dye in both overall (87% vs 71%, respectively; p=0.005) and bilateral (65% vs 43%, respectively; p=0.002) detection, but similar SLN detection rates compared to technetium(99) in both overall (87% vs 88%, respectively; p=0.83) and bilateral (65% vs 71%, respectively; p=0.36) detection. In eight cases, the SLN was in the para-aortic area and in 14 cases in the pre-sacral, hypogastric vein, or parametrial area. In nine cases, the SLN was positive for metastasis, and in seven cases the SLN was the only positive node. One SLN was falsely negative. No complications or anaphylactic reactions occurred.

CONCLUSION

Intra-operative SLN mapping using cervical injection is feasible in patients with endometrial cancer and yields adequate detection rates. It allows mapping of SLNs in areas (pre-sacral, hypogastric vein, parametrial) not routinely sampled. Given the poorer performance of blue dye, surgeons may omit its use if a combination of ICG and technetium(99) is used.

Techniques that accurately identify the sentinel lymph node in cancer

Sentinel lymph node (SLN) biopsy has become the gold standard for patients with melanoma and breast cancer but it’s clinical application in other solid tumor types such as cancers of the esophagus, stomach, colon and rectum, head and neck, penis, uterine cervix and endometrium has been somewhat limited. Commonly used mapping techniques utilizing the combination of radiocolloid and blue dye may result in reduced SLN detection and increased false negative rates when applied to cancers with more complex lymphatic drainage patterns. Novel localization techniques including near infrared fluorescence, high resolution imaging and molecular targeted agents have been developed to address the limitations of conventional SLN detection practices in many solid tumor types. This article reviews the indications, techniques and detection rates for SLN biopsy in several different solid tumor types as well as the promising novel techniques created to address the contemporary limitations of this procedure.

Methylene blue staining: a new technique for identifying intersegmental planes in anatomic segmentectomy

BACKGROUND

Pulmonary segmentectomy is being increasingly used to resect small lung nodules; however, identifying the intersegmental plane is difficult. We describe a new methylene blue staining technique that we developed to identify the intersegmental planes in anatomic segmentectomy using video-assisted thoracic surgery (VATS) or thoracotomy and to evaluate its feasibility and safety.

METHODS

Between October 2013 and December 2013, 14 consecutive patients with lung disease underwent anatomic segmentectomy at our institution (10 VATS, 4 conventional thoracotomy). Methylene blue 0.1% (20 mL) was slowly injected into the bronchus of the target pulmonary segments using an intravenous needle after division of the artery, vein, and bronchus of the target segments, and the boundaries were detected, followed by anatomic segmentectomy.

RESULTS

The staining took only 3 min. The target pulmonary segments stained blue, allowing for the clear identification of the intersegmental plane on both the surface and in the lung parenchyma, and all operations were successfully completed. Staining did not affect pathologic examination of the resected specimens. The fluid that drained from the chest tube and the patients' sputum, urine, and feces were not blue. There were no perioperative deaths or major complications.

CONCLUSIONS

To our knowledge, this study is the first to report a safe and feasible methylene blue staining method for identifying the lung segment borders that does not require any special equipment. More importantly, this method can clearly detect the intersegmental planes on the pleural surface and within the lung parenchyma, enabling thoracic surgeons to accurately perform anatomic segmentectomy.

A prospective study on sentinel lymph node biopsy in early oral cancers using methylene blue dye alone

Sentinel Lymph Node (SLN) biopsy using a combination of radioisotopes and blue dyes have a good accuracy rate in predicting subclinical neck nodal metastases in head and neck cancers. However, the limited availability of lymphoscintigraphy facilities in India requires exploration of alternative methods of SLN detection. We evaluated the feasibility of using methylene blue dye alone in detecting SLN in cN0 early oral cancers. 32 patients with cN0 early (T1, T2) oral squamous cell cancers underwent SLN biopsy using peri tumoural methylene blue dye injection. Blue dye stained (SLN) nodes were sent for frozen section analyses. Patients who had microscopic metastases in SLN underwent modified radical neck dissections and the rest underwent selective neck dissections. Paraffin sections and IHC studies were done on all nodes. SLN was identified in 29 patients (Identification rate = 90.6 %) of which SLN was positive for metastases on frozen section in 5 patients. The sensitivity, specificity and NPV of SLN with frozen section were 80 %, 95.8 % and 95.8 % respectively. IHC with cytokeratins increased the sensitivity (100 %) and NPV (100 %) at the loss of specificity (87.5 %). Methylene blue dye alone can be successfully used for SLN identification in early oral cancers with a good accuracy and sensitivity. This method will be of use especially in resource limited countries and centres where nuclear medicine facilities are not widely available. However, it has to be validated by larger randomised multi institutional trials for wider applicability. Immunohistochemistry increases the sensitivity and negative predictive value of SLN but its applicability in real time decision making is limited.

Polarization-sensitive multimodal imaging for detecting breast cancer

Intraoperative delineation of breast cancer is a significant problem in surgical oncology. A reliable method for demarcation of malignant breast tissue during surgery would reduce the re-excision rate due to positive margins. We present a novel method of identifying breast cancer margins using combined dye-enhanced wide-field fluorescence polarization imaging for en face cancer margins and polarization-sensitive (PS) optical coherence tomography (OCT) for cross-sectional evaluation. Tumor specimens were collected following breast surgery, stained with methylene blue, and imaged. Wide-field fluorescence polarization images were excited at 640 nm and registered between 660 and 750 nm. Standard and PS OCT images were acquired using a commercial 1,310-nm swept-source system. The imaging results were validated against histopathology. Statistically significant higher fluorescence polarization of cancer as compared with both normal and fibrocystic tumor tissue was measured in all the samples. Fluorescence polarization delineated lateral breast cancer margins with contrast superior to that provided by OCT. However, OCT complemented fluorescence polarization imaging by facilitating cross-sectional inspection of tissue. PS OCT yielded higher contrast between cancer and connective tissue, as compared with standard OCT. Combined PS OCT and fluorescence polarization imaging shows promise for intraoperative delineation of breast cancer.

Efficacy of Methylene Blue in Sentinel Lymph Node Biopsy for Early Breast Cancer

OBJECTIVE

Sentinel lymph node biopsy is the recommended approach in the evaluation of axilla during breast cancer surgery. In this study, results of patients who underwent methylene blue sentinel lymph node biopsy were evaluated.

MATERIALS AND METHODS

The study included 32 female patients with T1 and T2 tumors. 5 ml of 1% methylene blue was injected into the peritumoral area or around the cavity. The axillary sentinel lymph node was found and removed, and then axillary dissection was performed. The sentinel lymph node and axillary dissection specimen were histopathologically examined and the results were compared.

RESULTS

The sentinel lymph node was found in 30 (94%) patients. Lymph node metastasis was not observed in 17 patients in both the sentinel lymph node and axilla. Two patients had metastasis in the axilla although this was not detected in sentinel lymph node. Eleven patients had metastasis both in the sentinel lymph node and in the axilla. The accuracy rate was 93%, and the false negativity rate was identified as 15%.

CONCLUSION

Sentinel lymph node biopsy by methylene blue is a method that can be applied with high accuracy. Methylene blue can be considered as an alternative to isosulphane blue in sentinel lymph node biopsy.

Development of a Hybrid Nanoprobe for Triple-Modality MR/SPECT/Optical Fluorescence Imaging

Hybrid clinical imaging is an emerging technology, which improves disease diagnosis by combining already existing technologies. With the combination of high-resolution morphological imaging, i.e., MRI/CT, and high-sensitive molecular detection offered by SPECT/PET/Optical, physicians can detect disease progression at an early stage and design patient-specific treatments. To fully exploit the possibilities of hybrid imaging a hybrid probe compatible with each imaging technology is required. Here, we present a hybrid nanoprobe for triple modality MR/SPECT/Fluorescence imaging. Our imaging agent is comprised of superparamagnetic iron oxide nanoparticles (SPIONs), labeled with ^99mTc and an Alexa fluorophore (AF), together forming ^99mTc-AF-SPIONs. The agent was stable in human serum, and, after subcutaneous injection in the hind paw of Wistar rats, showed to be highly specific by accumulating in the sentinel lymph node. All three modalities clearly visualized the imaging agent. Our results show that a single imaging agent can be used for hybrid imaging. The use of a single hybrid contrast agent permits simultaneous hybrid imaging and, more conventionally, allow for single modality imaging at different time points. For example, a hybrid contrast agent enables pre-operative planning, intra-operative guidance, and post-operative evaluation with the same contrast agent.

Real-time fluorescence image-guided oncologic surgery

Medical imaging plays a critical role in cancer diagnosis and planning. Many of these patients rely on surgical intervention for curative outcomes. This requires a careful identification of the primary and microscopic tumors, and the complete removal of cancer. Although there have been efforts to adapt traditional-imaging modalities for intraoperative image guidance, they suffer from several constraints such as large hardware footprint, high-operation cost, and disruption of the surgical workflow. Because of the ease of image acquisition, relatively low-cost devices and intuitive operation, optical imaging methods have received tremendous interests for use in real-time image-guided surgery. To improve imaging depth under low interference by tissue autofluorescence, many of these applications utilize light in the near-infrared (NIR) wavelengths, which is invisible to human eyes. With the availability of a wide selection of tumor-avid contrast agents, advancements in imaging sensors, electronic and optical designs, surgeons are able to combine different attributes of NIR optical imaging techniques to improve treatment outcomes. The emergence of diverse commercial and experimental image guidance systems, which are in various stages of clinical translation, attests to the potential high impact of intraoperative optical imaging methods to improve speed of oncologic surgery with high accuracy and minimal margin positivity.

Adverse reaction; patent blue turning patient blue

The authors report a severe anaphylactic reaction to Patent Blue V dye used in sentinel node biopsy for lymphatic mapping during breast cancer surgery to stage the axilla. Patent Blue dye is the most widely used in the UK; however, adverse reactions have been reported with the blue dye previously. This case highlights that reactions may not always be immediately evident and to be vigilant in all patients that have undergone procedures using blue dye. If the patients are not responding appropriately particularly during an anaesthetic, one must always think of a possible adverse reaction to the dye. All surgical patients should give consent for adverse reactions to patent blue dye preoperatively. Alternative agents such as methylene blue are considered.