Indocyanine Green Fluorescence Versus Blue Dye or Radioisotope Regarding Detection Rate of Sentinel Lymph Node Biopsy and Nodes Removed in Breast Cancer: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis of diagnostic performance of fluorescein-guided sentinel lymph node biopsy in early breast cancer

BACKGROUND

Evaluation of axillary lymph nodes status in cN0 axilla is performed by sentinel lymph node biopsy (SLNB) utilizing a combination of radioactive isotope and blue dye or alternative to isotope like Indocyanine green (ICG). Both are very resource-intensive; which has prompted development of low-cost technique of Fluorescein Sodium (FS)-guided SLNB. This systematic review and meta-analysis evaluate the diagnostic performance of FS-guided SLNB in early breast cancer.

OBJECTIVES

The objective was to evaluate the diagnostic performance of FS for sentinel lymph node biopsy.

METHODS

Eligibility criteria: Studies where SLNB was performed using FS.

INFORMATION SOURCES

PubMed, EMBASE, Cochrane library and online clinical trial registers. Risk of bias: Articles were assessed for risk of bias using the QUADAS-2 tool.

SYNTHESIS OF RESULTS

The main summary measures were pooled Sentinel Lymph Node Identification Rate (SLN-IR) and pooled False Negative Rate (FNR) using random-effects model.

RESULTS

A total of 45 articles were retrieved by the initial systematic search. 7 out of the 45 studies comprising a total of 332 patients were included in the meta-analysis. The pooled SLN-IR was 93.2% (95% confidence interval [CI], 0.87-0.97; 87% to 97%). Five validation studies were included for pooling the false negative rate and included a total of 211 patients. The pooled FNR was 5.6% (95% confidence interval [CI], 2.9-9.07).

CONCLUSION

Fluorescein-guided SLNB is a viable option for detection of lymph node metastases in clinically node negative patients with early breast cancer. It achieves a high pooled Sentinel Lymph Node Identification Rate (SLN-IR) of 93% with a false negative rate of 5.6% for the detection of axillary lymph node metastasis.

Surgical margin status outcome of intraoperative indocyanine green fluorescence-guided laparoscopic hepatectomy in liver malignancy: a systematic review and meta-analysis

BACKGROUND

Hepatectomy stands as a curative management for liver cancer. The critical factor for minimizing recurrence rate and enhancing overall survival of liver malignancy is to attain a negative margin hepatic resection. Recently, Indocyanine green (ICG) fluorescence imaging has been proven implemental in aiding laparoscopic liver resection, enabling real-time tumor identification and precise liver segmentation. The purpose of this study is to conduct a systematic review and meta-analysis to ascertain whether ICG-guided laparoscopic hepatectomy yields a higher incidence of complete tumor eradication (R0) resections.

METHODS

The search encompassed databases such as PubMed, Cochrane Library database, Scopus, ScienceDirect, and Ovid in April 2024, in strict adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies involving patients with malignant liver lesions who underwent ICG-guided laparoscopic hepatectomy and reported R0 resection outcomes were eligible for inclusion in this review.

RESULTS

In a total of seven studies, involving 598 patients, were included in the meta-analysis. The ICG demonstrated a significantly elevated R0 resection rate compared to the non-ICG group [98.6% (359/364) vs. 93.1% (339/364), odds ratio (OR) = 3.76, 95% confidence intervals (CI) 1.45-9.51, P = 0.005]. Notably, no heterogeneity was observed (I2 = 0%, P = 0.5). However, the subtype analysis focusing on hepatocellular carcinoma [98.2% (165/168) vs. 93.6% (161/172), OR = 3.34, 95% CI 0.94-11.91, P = 0.06) and the evaluation of margin distance (4.96 ± 2.41 vs. 2.79 ± 1.92 millimeters, weighted mean difference = 1.26, 95% CI -1.8-4.32, P = 0.42) revealed no apparent differences. Additionally, the incidence of overall postoperative complications was comparable between both groups, 27.6% (66/239) in the ICG group and 25.4% (75/295) in the non-ICG group (OR = 0.96, 95% CI 0.53-1.76, P = 0.9). No disparities were identified in operative time, intraoperative blood loss, postoperative blood transfusion, and length of hospital stay after the surgery.

CONCLUSIONS

The implementation of ICG-guided laparoscopic hepatectomy can be undertaken with confidence, as it does not compromise either intraoperative or postoperative events. Furthermore, the ICG-guided approach is beneficial to achieving a complete eradication of the tumor during hepatic resection.

TRIAL REGISTRATION

PROSPERO registration number CRD42023446440.

Indocyanine green fluorescence versus blue dye, technetium-99M, and the dual-marker combination of technetium-99M + blue dye for sentinel lymph node detection in early breast cancer-meta-analysis including consistency analysis

BACKGROUND

Axillary sentinel lymph node biopsies are standard of care in patients with breast cancer and no clinically apparent metastases. Traditionally, technetium-99m, blue dye, or both have been used to identify sentinel lymph nodes. However, blue dyes miss up to 40% of sentinel lymph nodes, while technetium-99m use is complex, costly, and exposes patients to radiation. Over the past decade, studies have consistently found the biologically inert fluorescent indocyanine green to be 95% to 100% sensitive in detecting breast cancer sentinel lymph nodes, yet indocyanine green remains infrequently used.

METHODS

We conducted an extensive meta-analysis comparing indocyanine green against blue dye, technetium-99m, and the dual-marker combination of technetium-99m + BD. Unlike prior meta-analyses that only assessed either per-case or per-node sentinel lymph node detection, we analyzed the following 5 metrics: per-case and per-node sentinel lymph node detection and metastasis-positive sentinel lymph node sensitivity, and mean number of sentinel lymph nodes/case. We further examined the consistency and magnitude of between-study superiority and statistically significant within-study superiority of each marker against others.

RESULTS

For every metric and analysis approach, indocyanine green was clearly superior to blue dye and at least non-inferior, if not superior, to technetium-99m and technetium-99m + blue dye. Assessing the consistency of superiority by at least 2.0%, indocyanine green was superior to blue dye 73 times versus 1, to technetium-99m 42 times versus 9, and to technetium-99m + blue dye 6 times versus 0. Within-study statistically significant differences favored indocyanine green over blue dye 29 times versus 0 and over technetium-99m 11 times versus 2.

DISCUSSION

For sentinel lymph node detection in patients with breast cancer with no clinically apparent metastases, indocyanine green is clearly and consistently superior to blue dye and either non-inferior or superior to technetium-99m and technetium-99m + blue dye.

Clinical use of Indocyanine green fluorescence method for sentinel lymph node biopsy in breast cancer in France in 2021

INTRODUCTION

Indocyanine green (ICG) for axillary sentinel lymph node (SLN) detection in early breast cancer is at least equivalent to radioisotopic and/or colorimetric techniques. This procedure has not yet been recommended by learned societies in France. Following the recent drug approval of Infracyanin ® in this indication, we wished to study the use of ICG in France.

METHODS

We conducted a web-based survey among members of multiple French breast cancer societies throughout November 2021. The survey assessed the profile of the respondent, the use or not of ICG for the detection of SLN in breast cancer, the technique used and the opinion of non-users and their expectations on the subject.

RESULTS

Seventy-five surgeons participated. More than a third (37 %) have been using ICG for the detection of SLN in breast cancer for 2 to 3 years. Technique was highly variable. According to 82.1 % of the respondents, less than 20 procedures are necessary to master the use of ICG. The main advantage reported for this method is the reduction of organizational constraints. The obstacles to the use of the ICG are the near infra-red camera equipment, but also the lack of validation by the French guidelines. Among non-users, 83 % would like to develop this technique in their center and 72.3 % are interested in training on this subject.

CONCLUSION

This work highlights the need for French learned societies to take a stand on this issue but also the need to carry out studies on the technical aspects in order to standardise practices.

Evaluation of learning curve with Indocyanine Green (IcG) versus blue dye for sentinel lymph node biopsy in breast cancer

BACKGROUND

Indocyanine green (IcG) is an alternative to isosulfan blue (IB) for sentinel lymph node (SLN) mapping in breast cancer (BC). IcG carries improved cost and safety, but oncologic data upon implementation in practice is limited. We evaluated the learning curve defined as oncologic yield and operative (OR) time for IcG in SLN mapping in BC.

METHODS

Retrospective review of patients >18 years with cTis-2 cN0 BC undergoing surgery first with SLN biopsy using IB or IcG. Analysis compared IB versus IcG across three time cohorts.

RESULTS

Of 278 patients, 77 received IB and 201 received IcG. OR time was longer for IcG (p ​= ​0.022). There was no difference in oncologic yield between groups (p ​= ​0.35, p ​= ​0.61).

CONCLUSIONS

Surgeons may be able to safely transition from IB to IcG for patients with early-stage breast cancer undergoing surgery first. Individuals should track their own data to confirm safety of the technique.

An Updated Review on the Emerging Role of Indocyanine Green (ICG) as a Sentinel Lymph Node Tracer in Breast Cancer

Sentinel lymph node biopsy (SLNB) has become the standard of care for clinically node-negative breast cancer and has recently been shown by clinical trials to be also feasible for clinically node-positive patients treated with primary systemic therapy. The dual technique using both radioisotope (RI) and blue dye (BD) as tracers for the identification of sentinel lymph nodes is considered the gold standard. However, allergic reactions to blue dye as well as logistics issues related to the use of radioactive agents, have led to research on new sentinel lymph node (SLN) tracers and to the development and introduction of novel techniques in the clinical practice. Indocyanine green (ICG) is a water-soluble dye with fluorescent properties in the near-infrared (NIR) spectrum. ICG has been shown to be safe and effective as a tracer during SLNB for breast cancer and accumulating evidence suggests that ICG is superior to BD and at least comparable to RI alone and to RI combined with BD. Thus, ICG was recently proposed as a reliable SLN tracer in some breast cancer clinical practice guidelines. Nevertheless, there is lack of consensus regarding the optimal role of ICG for SLN mapping. Specifically, it is yet to be determined whether ICG should be used in addition to BD and/or RI, or if ICG could potentially replace these long-established traditional SLN tracers. This article is an updated overview of somerecent studies that compared ICG with BD and/or RI regarding their accuracy and effectiveness during SLNB for breast cancer.

New Alternative Techniques for Sentinel Lymph Node Biopsy

Background and Objectives: This review paper highlights the key alternatives to the blue dye/radioisotope method of sentinel lymph node biopsy (SLNB). It analyses the research available on these alternative methods and their outcomes compared to the traditional techniques. Materials and Methods: This review focused on fifteen articles, of which five used indocyanine green (ICG) as a tracer, four used magnetic tracers, one used one-step nucleic acid amplification (OSNA) and Metasin (quantitative reverse transcriptase-polymerase chain reaction), one used the photosensitiser talaporfin sodium, one used sulphur hexafluoride gas microbubbles, one used CT-guided lymphography and two focused on general SLNB technique reviews. Results: Of the 15 papers analysed, the sentinel node detection rates were 69-100% for indocyanine green, 91.67-100% for magnetic tracers, 81% for talaporfin sodium, 9.3-55.2% for sulphur hexafluoride gas microbubbles, 90.5% for CTLG and 82.7-100% for one-step nucleic acid amplification. Conclusions: Indocyanine green fluorescence (ICG) and magnetic tracers have been proven non-inferior to traditional blue dye and isotope regarding SLNB localisation. Further studies are needed to investigate the use of these techniques in conjunction with each other and the possible use of language learning models. Dedicated studies are required to assess cost efficacy and longer-term outcomes.

Comparison of Sentinel Lymph Node Biopsy by Blue Dye Conjunction With Indocyanine Green or Radioisotope in Early-Stage Breast Cancer: A Prospective Single-Center Observational Study

Background

Although radioisotope (RI) combined with blue dye (BD) is the standard technique for sentinel lymph node (SLN) biopsy in breast cancer, the use of RI is limited at some institutions due to the specific equipment needed. Indocyanine green (ICG) fluorescence detection has been developed as a potential substitute for RI method. However, reports on the sensitivity of ICG and RI techniques in detecting SLN are inconsistent; hence, the present study was designed to compare the clinical efficacy between the combined method of ICG + BD (ICG-B) and RI + BD (RI-B).

Methods

A prospective observational study was performed that identified 138 breast cancer patients who had undergone lymphatic mapping and SLN biopsy with ICG-B or RI-B. The SLN detection rate, positive SLN counts, and lymph node metastasis between the 2 groups were compared.

Results

A total of 71 patients were recruited in the ICG-B group, while 67 were recruited in the RI-B group. The SLN detection rate was 100% in both the ICG-B and RI-B groups. Lymph node metastasis was found in 13 patients using ICG-B and in 12 patients using the RI-B technique (18.31% vs 17.91%, respectively; P = .61). No significant differences were observed in the positive SLN counts (3.12 ± 2.01 vs 3.33 ± 2.24, P = .37) between the 2 groups.

Conclusions

Indocyanine green combined with BD has an equal efficacy compared with RI plus BD when performing an axillary SLN biopsy in breast cancer. The ICG plus BD procedure is a promising alternative to traditional standard mapping methods.

Endometrial cancer intraoperative sentinel lymph node identification can effectively guide treatment

OBJECTIVE

To explore the significance of intraoperative sentinel lymph node (SLN) identification in endometrial cancer.

METHODS

We retrospectively analyzed the clinical data of 56 patients with intraoperative SLN recognition (group A) and 50 patients without intraoperative SLN recognition (group B). SLN and pelvic abdominal lymph node distribution, SLN recognition rate, SLN recognition effect, mortality, the incidence of adverse events, and cumulative survival rate were statistically analyzed.

RESULTS

SLN were identified and removed in 41 of the 56 patients, with a recognition rate of 82.14% (46/56). The sensitivity of SLN was 83.72%, the specificity was 84.62%, and the negative predictive value was 61.11%. There were 15 patients with no SLN metastasis found in the pathological examination during the operation, among which two patients with poorly differentiated adenocarcinoma and clinical stage II patients underwent immunohistochemical staining, and three patients showed SLN micro-metastasis but no cancer tissue metastasis in the lymph node dissection. There was no significant difference in the incidence of total adverse events between group A and group B (P>0.05). The cumulative survival rate of group A was higher than that of group B (P=0.018).

CONCLUSION

Intraoperative SLE identification can avoid false negative results, is safe and feasible, and can prolong the survival time of patients with endometrial cancer.

Questionnaire study of application about sentinel lymph node biopsy surgery in locally advanced breast cancer patients who received neoadjuvant chemotherapy

Background

Nodal staging from sentinel lymph node (SLN) biopsy has become the standard procedure for early-stage breast cancer patients. SLN biopsy implementation after chemotherapy has previously been evaluated. This questionnaire study aimed to investigate the current trend of SLN biopsy after neoadjuvant chemotherapy (NAC) for locally advanced breast cancer.

Methods and materials

We conducted a web-based survey among breast surgeons who are members of the Korean Breast Cancer Society. The survey comprised 14 questions about axillary surgery after NAC.

Results

Of 135 respondents, 48.1% used a combined method of dye and radioactive isotope (RI). In the absence of SLN metastasis, 67.7% would perform only SLN biopsy, while 3% would perform ALN dissection. In case of SLN metastasis, the proportions of surgeons who would proceed with ALN dissection were 60.2% and 67.2% for less than two and more than three positive SLNs, respectively.

Conclusion

The present study confirmed the increasing tendency to adopt SLN biopsy for axillary staging in patients who achieved complete response with initial nodal metastasis. It could be expected that the mapping methods for patients receiving NAC have become diverse, including RI, vital dye, and indocyanine green fluorescence. The implementation of SLN biopsy after NAC will grow in the coming years due to an increasing demand of minimally invasive surgery.

Fluorescence Imaging to Identify and Preserve Fifth Intercostal Sensory Nerves during Bilateral Nipple-sparing Mastectomies

The use of nipple-sparing mastectomies has increased steadily over the past 10-15 years. However, one major source of patient dissatisfaction with both skin- and nipple-sparing mastectomies is lost skin and/or nipple sensation postoperatively due to intraoperative, iatrogenic sensory nerve injury. We summarize the case of a 41-year-old woman with BRCA(+) breast cancer who underwent bilateral, risk-reducing nipple-sparing mastectomies, immediately followed by bilateral, direct-to-implant breast reconstruction, in whom a prototype fluorescent imaging camera was used to facilitate sensory nerve identification and preservation. Preoperatively, tactile and thermal quantitative sensory testing were performed using a 30-gauge needle to determine baseline sensory function over both breasts. Then, nipple-sparing mastectomies and direct-to-implant reconstruction were performed. Using a laterally-displaced submammary approach, the anterior intercostal artery perforator neurovascular pedicle was preserved. Then a prototype camera, which emits near-ultraviolet light, was used to detect nerve autofluorescence. Intraoperatively under near-ultraviolet light, both the fifth intercostal nerve and its sensory branches auto-fluoresced clearly, so that surgery was completed without apparent injury to the fifth intercostal nerve or any of its branches. Postoperatively, the patient reported full sensory function throughout both breasts and both nipple-areolar complexes, which was confirmed on both tactile and thermal sensory testing at 3-month follow-up. The patient experienced no complications and rated her overall satisfaction with surgery on both breasts as 10 out of 10. To our knowledge, this is the first time sensory nerve auto-fluorescence has been reported to reduce the likelihood of intraoperative, iatrogenic nerve injury and preserve sensory function.

Indocyanine green combined with methylene blue versus methylene blue alone for sentinel lymph node biopsy in breast cancer: a retrospective study

BACKGROUND

Recent studies have shown that near-infrared (NIR) fluorescence imaging using Indocyanine green (ICG) may improve the efficiency of sentinel lymph node biopsy (SLNB). This study aimed to assess the effectiveness of the combination of ICG and methylene blue (MB) in breast cancer patients undergoing SLNB.

PATIENTS AND METHOD

We evaluated ICG plus MB (ICG + MB) identification effectiveness with MB alone using retrospective analysis. From 2016 to 2020, we collected data on 300 eligible breast cancer patients who got SLNB treatment in our institution by ICG + MB or MB alone. By comparing the distribution of clinicopathological characteristics, the detection rate of sentinel lymph nodes (SLNs) and metastatic SLNs, as well as the total number of SLNs in the two groups, we were able to assess the imaging efficiency.

RESULTS

Fluorescence imaging allowed 131 out of 136 patients in the ICG + MB group to find SLNs. ICG + MB group and MB group had detection rates of 98.5% and 91.5% (P = 0.007, χ² = 7.352), respectively. Besides, the ICG + MB approach was able to produce improved recognition outcomes. What's more, compared with the MB group, the ICG + MB group can identify more lymph nodes (LNs) (3.1 to 2.6, P = 0.000, t = 4.447). Additionally, in the ICG + MB group, ICG could identify more LNs than MB (3.1 vs 2.6, P = 0.004, t = 2.884).

CONCLUSION

ICG has high detection effectiveness for SLNs, and when paired with MB, the detection efficiency can be increased even further. Furthermore, the ICG + MB tracing mode does not involve radioisotopes, which has a lot of promise for clinical use and can take the place of conventional standard detection methods.

Sentinel Lymph Node Techniques in Urologic Oncology: Current Knowledge and Application

Lymph node (LN) metastases have a significant negative impact on the prognosis of urological malignancies. Unfortunately, current imaging modalities are insufficient when it comes to detecting micrometastases; thus, surgical LN removal is commonly used. However, there is still no established ideal lymph node dissection (LND) template, leading to unnecessary invasive staging and the possibility of missing LN metastases located outside the standard template. To address this issue, the sentinel lymph node (SLN) concept has been proposed. This technique involves identifying and removing the first group of draining LNs, which can accurately stage cancer. While successful in breast cancer and melanoma, the SLN technique in urologic oncology is still considered experimental due to high false-negative rates and lack of data in prostate, bladder, and kidney cancer. Nevertheless, the development of new tracers, imaging modalities, and surgical techniques may improve the potential of the SLN procedures in urological oncology. In this review, we aim to discuss the current knowledge and future contributions of the SLN procedure in the management of urological malignancies.

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.

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.

99mTc-labeled colloid SPECT/CT versus planar lymphoscintigraphy for sentinel lymph node detection in patients with breast cancer: a meta-analysis

Background

The aim of this meta-analysis was to compare single-photon emission computed tomography (SPECT/CT) and planar lymphoscintigraphy (PL) in patients with primary breast cancer, undergoing lymphoscintigraphy at initial staging. Specifically, we assessed the detection rate (DR) for sentinel lymph node (SLN), the absolute number of detected SLNs by each technique, and the proportion of patients with additional SLNs detected by one technique compared to the other one. Finally, we aimed to evaluate the impact of SPECT/CT on the surgical approach.

Methods

Original articles, providing a head-to-head comparison between SPECT/CT and PL, including patients with primary breast cancer at first presentation, were searched in PubMed/MEDLINE and Scopus databases through March 31st, 2022. The DR of the imaging techniques was calculated on a per-patient analysis; studies were pooled on their odds ratios (ORs) with a random-effects model to assess the presence of a significant difference between the DRs of SPECT/CT and PL. The number of additional SLNs, calculated as relative risk (RR), and the pooled proportion of patients with additional SLNs using one imaging technique rather than the other one were investigated. The pooled ratio of surgical procedures (SLN harvesting) influenced by the use of SPECT/CT, according to the surgeons, was calculated.

Results

Sixteen studies with 2693 patients were eligible for the calculation of the DR of SPECT/CT and PL. The DR was 92.11% [95% confidence interval (95% CI) 89.32–94.50%] for SPECT/CT, and 85.12% (95% CI 80.58–89.15%) for PL, with an OR of 1.96 (95% CI 1.51–2.55) in favor of SPECT/CT. There was a relative risk of detection of larger number of SLNs (RR: 1.22, 95% CI 1.14–1.32; 12 studies; 979 patients) for SPECT/CT (n = 3983) compared to PL (n = 3321) and a significant proportion of patients with additional SLNs detected by SPECT/CT, which were missed by PL (18.88%, 95% CI: 11.72%-27.27%; 13 studies). Four articles, with a total number of 1427 patients, revealed that 23.98% of the surgical procedures benefited from the use of SPECT/CT.

Conclusions

This meta-analysis favors SPECT/CT over PL for the identification of SLN in patients with primary breast cancer at staging due to higher DR, more SLNs depicted, and a significant proportion of subjects with additional detected SLNs by SPECT/CT compared to PL. Furthermore, SPECT/CT positively influences the surgical procedure. However, PL remains a satisfactory imaging option for imaging departments not equipped with SPECT/CT due to its good patient-based DR.

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.

Diagnostic value of indocyanine green for sentinel lymph node mapping and lymph node metastasis in oral/oropharyngeal carcinoma

Indocyanine green (ICG) fluorescence-based sentinel lymph node (SLN) biopsy has been promoted to detect early metastasis of oral/oropharyngeal carcinoma, but its diagnostic value still remains unclear. In this letter, we identified 6 studies on ICG fluorescence based SLN in the detection of lymph node metastasis in oral/oropharyngeal carcinoma. For detection of metastatic lymph node, the overall sensitivity and specificity of the studies were 0.86 and 0.91, respectively. SROC curve was determined according to the combined sensitivity and specificity, and the overall area under the curve AUC was 0.93. On the whole, ICG fluorescence-based SLN biopsy showed promising effect for earlier detection and staging.

Recent Developments of ICG-Guided Sentinel Lymph Node Mapping in Oral Cancer

Sentinel lymph node (SLN) biopsy has gained attention as a method of minimizing the extent of neck dissection with a similar survival rate as elective neck dissection in oral cancer. Indocyanine green (ICG) imaging is widely used in the field of surgical oncology. Real-time ICG-guided SLN imaging has been widely used in minimally invasive surgeries for various types of cancers. Here, we provide an overview of conventional SLN biopsy and ICG-guided SLN mapping techniques for oral cancer. Although ICG has many strengths, it still has limitations regarding its potential use as an ideal compound for SLN mapping. The development of novel fluorophores and imaging technology is needed for accurate identification of SLNs, which will allow precision surgery that would reduce morbidities and increase patient survival.

Real-Time In Situ Navigation System With Indocyanine Green Fluorescence for Sentinel Lymph Node Biopsy in Patients With Breast Cancer

Background

The naked-eye invisibility of indocyanine green fluorescence limits the application of near-infrared fluorescence imaging (NIR) systems for real-time navigation during sentinel lymph node biopsy (SLNB) in patients with breast cancer undergoing surgery. This study aims to evaluate the effectiveness and safety of a novel NIR system in visualizing indocyanine green fluorescence images in the surgical field and the application value of combined methylene blue (MB) and the novel NIR system in SLNB.

Methods

Sixty patients with clinical node-negative breast cancer received indocyanine green (ICG) and MB as tracers. Two NIR system instruments, namely, lymphatic fluorescence imaging system (LFIS) designed by the University of Science and Technology of China and vascular imager by Langfang Mingde Medical Biotechnology Co., Ltd. (Langfang vascular imager), were used as navigation assistance to locate sentinel lymph nodes (SLNs). Excising the lymph nodes developed by both MB and ICG by two NIR systems or palpably suspicious as SLNs and undergoing rapid pathological examination.

Results

Both instruments exhibited 95% (57/60) success for real-time lymphatic fluorescent images. A total of 186 SLNs were identified, of which two were pathologically confirmed as lacking any lymph node tissue. SLN identification rate was 100% (184/184) for MB plus LFIS and 86.96% (160/184) for MB alone. The median number of SLNs identified by LFIS combined with MB was 3 (range of 1–8), which was significantly higher than that by MB alone at 2 (range 1–7) (P<0.05).

Conclusion

LFIS effectively detects SLNs in breast cancer, projects the fluorescence signals during surgery, and provides a continuous surgical navigation system without the need for a remote monitor. The ICG method navigated by combined LFIS and MB may be a promising alternative tracer for radioisotope in SLN mapping.

Clinical Trial Registration

This clinical trial was registered with the China Clinical Trial Center, registration number ChiCTR2000039542.

Technical Challenges in "Micro" Lymph Node Identification during Vascularized Submental Lymph Node Flap Harvesting

Background:

The outcome of autologous lymph node (LN) transfer has depended on the number of LNs in the donor site. Unknown accuracy of the LN counting method has thrown some doubts on the reliability of the previous statistics. This study aimed to assess the accuracy of naked eye (NK) and stereo microscopy (SM) as tools for LN count.

Methods:

In total, 40 vascularized submental LN flaps were harvested from 23 fresh cadavers. The colored polymer was injected into the external carotid arteries before the harvest. LNs in each flap were counted by NK, SM, and histology in sequential order.

Results:

An estimated 175 LNs were confirmed, 4.4 ± 1.8 per flap. NK sensitivity was 33.7% compared with that of SM at 63.5%. Both methods missed all micro-lymph nodes (micro-LNs), contributing to 5.1% (9 nodes) of all LNs. Non-LN structures (647 negative counts) were composed of fat lobules, salivary gland lobules, and muscle fibers. NK specificity was 98.0%, compared with that of SM at 96.1%. SM showed a higher false positive rate at 14.3%, compared with NK at 7.4%. False positive counts were located mostly in Ib sublevel.

Conclusions:

NK and SM are imperfect tools for LN count due to poor sensitivity. If the method needs to be applied, points of considerations are (1) undetectable micro-LNs, (2) interposition of LNs with the digastric muscle and submandibular salivary gland, (3) confusion of LNs with lobules of salivary gland supplied by glandular artery or fat lobules supplied by lobular artery.