New Technologies for Sentinel Lymph Node Detection

New techniques versus standard mapping for sentinel lymph node biopsy in breast cancer: a systematic review and meta-analysis

New tracers for sentinel lymph node biopsy (SLNB), as indocyanine green (ICG), superparamagnetic iron oxide (SPIO) and micro bubbles, have been recently introduced in clinical practice showing promising but variable results. We reviewed the available evidence comparing these new techniques with the standard tracers to evaluate their safety. To identify all available studies, a systematic search was performed in all electronic databases. Data regarding sample size, mean number of SLN harvested for patient, number of metastatic SLN and SLN identification rate of all studies were extracted. No significant differences were found in terms of SLNs identification rates between SPIO, RI and BD but with a higher identification rate with the use of ICG. No significant differences were also found for the number of metastatic lymph nodes identified between SPIO, RI and BD and the mean number of SLNs identified between SPIO and ICG versus conventional tracers. A statistically significant differences in favor of ICG was reported for the comparison between ICG and conventional tracers for the number of metastatic lymph nodes identified. Our meta-analysis demonstrates that the use of both ICG and SPIO for the pre-operative mapping of sentinel lymph nodes in breast cancer treatment is adequately effective.

Evaluation of Surgical Aid of Methylene Blue in Addition to Intraoperative Gamma Probe for Sentinel Lymph Node Extirpation in 116 Canine Mast Cell Tumors (2017-2022)

Methylene Blue (MB) is combined with radiopharmaceutical for intraoperative sentinel lymph node (SLN) mapping, but its role during SLN extirpation has not been investigated yet in veterinary medicine. The aim of this study was to assess whether MB increased surgical detection of SLN beyond the use of intraoperative gamma-probe (IGP) alone in clinically node-negative dogs with mast cell tumors (MCTs) following the detection of sentinel lymphocentrums (SLCs) via preoperative planar lymphoscintigraphy. Dogs enrolled underwent MCT excision and SLC exploration guided by both MB and IGP. Data recorded for each SLN were staining (blue/non-blue), radioactivity (hot/non-hot), and histopathological status (HN0-1 vs. HN2-3). A total of 103 dogs bearing 80 cutaneous, 35 subcutaneous, and 1 mucocutaneous MCTs were included; 140 SLCs were explored, for a total of 196 SLNs removed. Associating MB with IGP raised the SLNs detection rate from 90% to 95%. A total of 44% of SLNs were metastatic: 86% were blue/hot, 7% were only blue, 5% were only hot, and 2% were non-blue/non-hot. All HN3 SLNs were hot. Combining MB with IGP can increase the rate of SLN detection in dogs with MCTs; nonetheless, all lymph nodes identified during dissection should be removed, as they might be unstained but metastatic.

Axillary sentinel lymph node identification using superparamagnetic iron oxide versus radioisotope in early stage breast cancer: The UK SentiMag trial (SMART study)

BACKGROUND & OBJECTIVES

Sentinel lymph node biopsy (SLNB) is an accurate and reliable method for staging the axilla in early breast cancer. The gold standard technique for localizing the sentinel lymph node (SLN) is the use of radioisotope with or without blue dye. However, this technique has its limitations. Various alternatives have been explored to overcome the disadvantages of the standard SLNB technique and superparamagnetic iron oxide mapping agents have garnered significant attention. The SMART study aims to compare the magnetic technique using the superparamagnetic iron oxide particles (SPIO, Sienna+®) to the radioisotope technique (Tc99) +/- blue dye, for SLN identification in patients with early breast cancer.

METHODS

A prospective, multicenter study was done that recruited 109 clinically node-negative early-stage breast cancer patients from five centres in the United Kingdom (UK). The patients received radioisotope ± blue dye injections, followed by intraoperative injection of magnetic tracer prior to SLNB. The sentinel node identification rate was compared between the magnetic and standard techniques to evaluate detection rate (per patient and per node), non-inferiority and concordance.

RESULTS

Data was analysed for 107 patients. The per patient detection rate was 98.13% (105/107) when using the magnetic tracer and 92.26% (103/107) when using the standard technique. The nodal detection rate was 93.07% (188/202 nodes) when using the magnetic tracer and 96.53% (195/202) when using the standard technique. Of the 31 patients with positive sentinel lymph nodes (SLNs), all 31 (100%) were detected by both techniques.

CONCLUSION

Our study demonstrates that the magnetic technique is a feasible method for SLNB, with an identification rate that is not inferior to the standard technique. The magnetic technique offers a suitable alternative to the standard technique thereby avoiding the need for the complexities of nuclear medicine, the hazards of radiation and the anaphylaxis risk of blue dye.

Detection of Sentinel Lymph Nodes During Breast Cancer Surgery: A Literature Overview

Introduction. Detecting metastases is an important part of successful breast cancer treatment. Usually, the tumor tissue first spreads to the sentinel lymph nodes. Removal of the latter during surgery and histological examination allows to assess the patient’s di­sease stage, prognosis and treatment. The literature provides more than one approach or a combination of them, allowing us to accurately identify the breast’s sentinel lymph nodes and avoid removing all axillary lymph nodes. Purpose. To review the methods of intraoperative detection of breast sentinel lymph nodes presented in the literature. Research material and methods. Publications were searched using the specialized information search system Google Scholar. Keywords used in the search: breast sentinel lymph nodes, intraoperative detection. After evaluating the exclusion criteria, the review was based on 25 scientific publications. Results. 4 individual measures and 2 combinations of them can be used to detect sentinel breast lymph nodes during surgery. The materials used can be injected in 6 different ways. Conclusions. The combination of technetium-99m radiocolloid and methylene blue can be evaluated as the best method for intraoperative detection of sentinel lymph nodes in breast cancer patients. On the other hand, due to radiation and operating costs, more attention is being paid to the use of indocyanine green, superparamagnetic iron oxide, methylene blue dye, and the detection of metastases without surgery. Superficial methods of injecting the substance should be combined with deep ones due to the possibility of detecting extra-axillary sentinel lymph nodes of the breast. Ultimately, all decisions must be made on a case-by-case basis.

Sentinel lymph node mapping with computed tomography lymphography for mast cell tumours and a comparison between regional and sentinel lymph node histological status: Sixty-two cases

It is known that the regional lymph node (RLN) may not correspond to the sentinel lymph node (SLN) (the first lymph node draining the tumour), and many diagnostic techniques have recently been aimed at its detection. Although lymphoscintigraphy is the gold standard in both human and veterinary medicine for SLN mapping, it is relatively unavailable in veterinary medicine due to costs and difficult management of the radiotracer. This prospective study evaluated, as a first aim, the feasibility and sensitivity of the computed tomography lymphography (CTL) in detecting the SLN in 62 mast cell tumours (MCTs). The second aim was to evaluate the accuracy of the CTL in identifying the most representative lymph node of the patient's lymphatic status; the histological status of the SNL was compared with that of the RLN, to see in how many cases the patient's stage would have changed according to the RLN. When the RLN turned out to be also the SLN it was decided to excise, as a control LN, the one localised in the neighbourhood of the MCT (neighbouring lymph node; NLN). The detection rate was 90%, with failure of SLN identification in six cases. In 18 (32%) of 56 MCTs with a diagnostic CTL, the SLN did not correspond to the RLN. Forty-five MCTs were surgically removed, together with their corresponding SLN and RLN/NLN. Since the clinical stage of the patient would have changed in only 7% of cases, CTL is a reliable method of detecting the SLN and, for staging purposes, there is no need to remove other LNs.

Evaluation of New Tracers in the Identification of Sentinel Lymph Node in Patients with Early Breast Cancer

Purpose

Sentinel node mapping is the standard of care for evaluation of axilla for women with early node negative breast cancer. Validation of a new tracer for sentinel node biopsy requires full axillary lymph node dissection to establish its performance indicators. This exposes about 70% of women to unnecessary axillary dissection with its attendant morbidity.

Aims and Objective

To investigate the predictive value of identification of sentinel lymph nodes by a tracer for knowing its sensitivity and false-negative rates (FNR).

Methods

A linear regression on data from a network meta-analysis was carried out, and the correlation between identification and sensitivity and its predictive value were ascertained.

Results

A strong linear relationship was observed between identification and sensitivity of sentinel node biopsy (correlation coefficient r = 0.97). The sensitivity and false negativity can be predicted by the identification rate. An identification rate of 93% corresponds to sensitivity = 90.51% and a FNR = 9.49%. The current literature on newer tracers has been succinctly reviewed.

Conclusion

The linear regression demonstrated a very high predictive value of identification rate for ascertaining the sensitivity and FNRs of sentinel node biopsy. A new tracer for sentinel node biopsy can be introduced in clinical practice, if it achieves an identification rate of 93% or more.

Development of scalable lymphatic system in the 4D XCAT phantom: Application to quantitative evaluation of lymphoma PET segmentations

BACKGROUND

Digital anthropomorphic phantoms, such as the 4D extended cardiac-torso (XCAT) phantom, are actively used to develop, optimize, and evaluate a variety of imaging applications, allowing for realistic patient modeling and knowledge of ground truth. The XCAT phantom defines the activity and attenuation for a simulated patient, which includes a complete set of organs, muscle, bone, and soft tissue, while also accounting for cardiac and respiratory motion. However, the XCAT phantom does not currently include the lymphatic system, critical for evaluating medical imaging tasks such as sentinel node detection, node density measurement, and radiation dosimetry.

PURPOSE

In this study, we aimed to develop a scalable lymphatic system in the XCAT phantom, to facilitate improved research of the lymphatic system in medical imaging. Using this scalable lymphatic system, we modeled the lymph node conglomerate pathology that is characteristically observed in primary mediastinal B-cell lymphoma (PMBCL). As an extended application, we evaluated positron emission tomography (PET) image quantification of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of these simulated lymphomas, though the phantoms may be applied to other imaging modalities and study design paradigms (e.g., image quality, detection).

METHODS

A template model for the lymphatic system was developed based on anatomical data from the Visible Human Project of the National Library of Medicine. The segmented nodes and vessels were fit with non-uniform rational basis spline surfaces, and multichannel large deformation diffeomorphic metric mapping was used to propagate the template to different XCAT anatomies. To model conglomerates observed in PMBCL, lymph nodes were enlarged, converged within the mediastinum, and tracer concentration was increased. We used the phantoms as inputs to a PET simulation tool, which generated images using ordered subsets expectation maximization reconstruction with 2-8 mm Gaussian filters. Fixed thresholding (FT) and gradient segmentation were used to determine MTV and TLG. Percent bias (%Bias) and coefficient of variation (COV) were computed as measures of accuracy and precision, respectively, for each MTV and TLG measurement.

RESULTS

Using the methodology described above, we introduced a scalable lymphatic system in the XCAT phantom, which allows for the radioactivity and attenuation ground truth to be generated in 116 ± 2.5 s using a 2.3 GHz processor. Within the Rhinoceros interface, lymph node anatomy and function were modified to create a cohort of 10 phantoms with lymph node conglomerates. Using the lymphoma phantoms to evaluate PET quantification of MTV, mean %Bias values were -9.3%, -41.3%, and 20.9%, while COV values were 4.08%, 7.6%, and 3.4% using 25% FT, 40% FT, and gradient segmentations, respectively. Comparatively for TLG, mean %Bias values were -27.4%, -45.8%, and -16.0%, while COV values were 1.9%, 5.7%, and 1.4%, for the 25% FT, 40% FT, and gradient segmentations, respectively.

CONCLUSIONS

In this work, we upgraded the XCAT phantom to include a lymphatic system, comprised of a network of 276 scalable lymph nodes and corresponding vessels. As an application, we created a cohort of phantoms with lymph node conglomerates to evaluate lymphoma quantification in PET imaging, which highlights an important application of this work.

Biodistribution, pharmacokinetics and excretion studies of intravenously injected nanoparticles and extracellular vesicles: Possibilities and challenges

There is a large interest in developing nanoparticles and extracellular vesicles for delivery of therapeutics or imaging agents. Regulatory approval of such products requires knowledge about their biodistribution, metabolism and excretion. We here discuss possibilities and challenges of methods used for such studies, which most often are performed after labelling with radioactive isotopes or fluorescent molecules. It is important to evaluate if the labelled and unlabeled products can be expected to behave similarly in the body. Furthermore, one needs to critically consider whether the labels are still associated with the product at the time of analyses. We discuss advantages and disadvantages of different imaging modalities such as PET, SPECT, MRI, CT, ultrasound and optical imaging for whole-body biodistribution, and describe how to estimate the amount of labelled product in harvested organs and tissue. Microscopy of cells and tissues and various mass spectrometry methods are also discussed in this review.

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.

Surgical data science - from concepts toward clinical translation

Recent developments in data science in general and machine learning in particular have transformed the way experts envision the future of surgery. Surgical Data Science (SDS) is a new research field that aims to improve the quality of interventional healthcare through the capture, organization, analysis and modeling of data. While an increasing number of data-driven approaches and clinical applications have been studied in the fields of radiological and clinical data science, translational success stories are still lacking in surgery. In this publication, we shed light on the underlying reasons and provide a roadmap for future advances in the field. Based on an international workshop involving leading researchers in the field of SDS, we review current practice, key achievements and initiatives as well as available standards and tools for a number of topics relevant to the field, namely (1) infrastructure for data acquisition, storage and access in the presence of regulatory constraints, (2) data annotation and sharing and (3) data analytics. We further complement this technical perspective with (4) a review of currently available SDS products and the translational progress from academia and (5) a roadmap for faster clinical translation and exploitation of the full potential of SDS, based on an international multi-round Delphi process.

Assessment of Intraparenchymal Injection of 1% Patent Blue Dye in the Upper Outer Quadrant of the Breast to Identify Sentinel Lymph Node in Early Retro-Areolar Breast Cancer in Women: A Tertiary Centre Experience in Egypt

BACKGROUND

Sentinel lymph node biopsy is the gold standard for axillary assessment of patients with clinically node negative breast cancer. The current internationally accepted methods comprise of the usage of either a radioactive tracer, vital stains or the combination of both. However, in developing countries radioactive tracer is not widely used due to its high cost and limited availability. In addition, the classic retro-areolar blue dye injection has a high failure rate.

OBJECTIVE

Our study aimed to assess the efficacy of patent blue dye injection in the upper outer quadrant of the breast after validation by concurrent usage of radioactive nanocolloid, in comparison with the classic retro-areolar injection in identifying the sentinel node.

METHODS

A randomized control study involving 279 patients randomly divided into two groups. In group A lateral injection of 1% patent blue dye (validated by radioactive nanocolloid) was used, while subdermal patent blue dye injection in the retro-areolar space was performed in group B.

RESULTS

The new technique showed the promising results with lower failure rate (3.4%) in comparison with the classic retro-areolar patent blue injection (13.7%).

CONCLUSIONS

The lateral injection technique can be result in comparable results to the combination technique with the added benefit of being widely available and a cheaper option especially in developing countries.

Optimization of Sentinel Lymph Node Imaging Methodology Using Anionic Liposome and Hyaluronidase

The sentinel lymph node (SLN) is the first lymph node into which lymphatic fluid from tumor tissues flows. The development of a highly sensitive probe for detecting SLNs is desired for the lymph node dissection through intraoperative biopsy. We have previously shown that anionic liposomes tend to accumulate in lymph nodes and that macrophage uptake of liposomes contributes to their accumulation. In the present study, we found that among anionic lipids, phosphatidylserine (PS)-containing liposomes were substantially taken up by macrophages. We identified a new lipid composition to improve the SNL-selectivity of liposome accumulation based on Design-of-Experiment. The optimized PS-containing particles were more selectively accumulate to SLN lymph nodes than existing imaging agents indocyanine green. These results indicate the effectiveness of PS-containing anionic particles in SLN imaging.

Using Computed Tomography Lymphography for Mapping of Sentinel Lymph Nodes in Patients with Breast Cancer

Objectives

In breast cancer surgery, the combined use of the dye method and radioisotope (RI) method is recommended for identifying sentinel lymph nodes. However, the RI method is difficult to license, expensive, and difficult to introduce. Thus, we introduced computed tomography lymphography (CTLG) and investigated the characteristics and usefulness of CTLG.

Material and Methods

Among breast cancer patients who underwent surgery during a 6-year period from January 2013 to December 2018, CTLG was performed on 141 patients with clinically negative lymph node metastasis. These cases were then retrospectively investigated. The number and location of lymph vessel, true sentinel lymph nodes, and the positional relationships with surrounding muscles and blood vessels were confirmed from the constructed 3D images. The actual surgeries were then performed using a dye method with indigo carmine based on images obtained using CTLG.

Results

CTLG was able to identify lymph vessels and true sentinel lymph nodes in 131 of the 141 cases (92.91%). There were 97 patients in whom the first true sentinel lymph node reached from the breast was one node, 30 with two nodes, and 4 with three nodes. Moreover, there were three cases in which sentinel lymph nodes were present at Level II. During surgery, sentinel lymph nodes were identified in 131 patients (92.91%) using dye.

Conclusion

CTLG has a high identification rate in sentinel lymph nodes, and it is considered a convenient and useful examination method because a lot of information, such as the number and position of sentinel lymph nodes, can be obtained.

Sentinel lymph node mapping in breast cancer patients following neoadjuvant chemotherapy: systematic review and meta-analysis about head to head comparison of cN0 and cN + patients

PURPOSE

The effectiveness of sentinel lymph node (SLN) mapping and biopsy following neoadjuvant chemotherapy (NAC) in axillary lymph node staging of breast cancer (BCa) patients with initial clinical node positive status (cN +) compared to clinical node negative status (cN0) is not yet known. The aim of this meta-analysis was to compare the accuracy of SLN mapping following NAC in cN + and cN0 BCa patients.

METHODS

PubMed and Scopus were comprehensively reviewed to retrieve all the studies that performed SLN mapping/biopsy and standard axillary lymph node dissection on cN0 and cN + BCa patients following NAC. Pooled detection and false negative rates for N0 and N + patients including 95% confidence interval values (95% CI) were evaluated. Odds ratio (OR) and risk difference (RD) of SLN detection failure and false negative results were compared between two groups.

RESULTS

A total of 27 articles were included for SLN detection rate evaluation and 17 for false negative assessment. The OR and RD of detection failure in N + group compared with N0 group following NAC were 2.22 (p = 0.00, 95% CI 1.4-3.4) and 4% (p = 0.00, 95% CI 2-6%), respectively. The OR and RD of false negative rate were 1.6 (p = 0.01, 95% CI 1-2.6) and 8% (p = 0.02, 95% CI 1-14%), respectively.

CONCLUSION

SLN mapping in BCa patients following NAC shows high risk of detection failure and high false negative rate of SLN biopsy in cN + patients. In comparison with cN0 BCa patients, SLN mapping and biopsy after NAC was associated with almost two times higher odds of detection failure and false negative results in cN + patients; therefore, this method should not be recommended in this group of patients.

Long-term follow-up results of fluorescence and blue dye guided sentinel lymph node biopsy in early breast cancer

PURPOSE

This study aimed to assess the efficacy of the combination of indocyanine green (ICG) and methylene blue (MB) dye in early breast cancer patients undergoing sentinel lymph node biopsy (SLNB).

METHODS

Between January 2011 and December 2015, 1061 early breast cancer patients underwent SLNB were included. SLNB was performed for enrolled patients by injection of both ICG and MB. Detection rate, positivity, and number of sentinel lymph nodes (SLNs) by ICG and MB were analysed. Axillary recurrence and arm lymphedema at 5.6-year follow-up were reported.

RESULTS

The combination of ICG and MB resulted in a very high detection rate of 99.6%, the median number of sentinel lymph nodes was 3. A total of 374 histologically confirmed positive SLNs were detected in 237 patients, 96.6% of the positive patients and 94.1% of the positive nodes could be identified by the combination of ICG and MB. After a median follow-up of 5.6 (2-9.3) years, 0.64% of patients with negative SLNs had ipsilateral axillary recurrence, and the incidence of arm lymphedema was 2.1%.

CONCLUSIONS

Although the missing isotope control weakens the interpretation of the findings, the dual tracing modality of ICG and MB, without involvement of radioactive isotopes, was an effective method for SLNB in patients with early breast cancer.

TRIAL REGISTRATION

ACTRN12612000109808. Registered on 23 January 2012.

Low-cost Fluorescein as an Alternative to Radio-colloid for Sentinel Lymph Node Biopsy-a Prospective Validation Study in Early Breast Cancer

BACKGROUND

Sentinel lymph node biopsy (SLNB) using radio-pharmaceutical (RP) and a blue dye is gold standard for axillary staging in clinically node-negative early breast cancer. High costs and limited availability of RP and/or gamma probe are major deterrents in performing SLNB in developing countries. Fluorescence-guided SLNB can obviate the need for RP and gamma probe. Fluorescein is an inexpensive fluorescent lymphatic tracer. In this study, we compared SLN identification rate (SLN-IR) and false negative rates (FNR) of fluorescein-guided SLNB and radio-guided SLNB using ^99mTc-Sulfur-colloid, in isolation, or in combination with methylene blue dye (MBD).

METHODS

Sixty-five cN0 early and large operable breast cancer patients underwent validation SLNB using fluorescein (and blue LED light), ^99mTc-Sulfur-colloid (and gamma probe) and MBD. Inj Fluorescein 4% was injected, 1 ml each peri-tumoral and sub-areolar five minutes before axillary incision. Axillary dissection was performed irrespective of SLNB histology. The SLN-IR and FNR with various tracers and their combinations were compared.

RESULTS

The mean number of SLNs identified was 3.5 ± 1.8 (range 1-6). The SLN-IR using RP alone was 94%, fluorescein alone was 92%, and MBD alone was 82%. The SLN-IR using fluorescein plus MBD combination was 95.4%, compared to 97% using MBD plus RP combination. FNR was 6.3% using fluorescein plus MBD, as well as RP plus MBD combinations.

CONCLUSIONS

SLN-IR of > 90% and SLN-FNR of < 10% using fluorescein plus MBD combination are in acceptable range, and are comparable to that of RP plus MBD combination. Fluorescein can replace RP for performing SLNB, in combination with MBD.

Does near-infrared fluorescent cholangiography with indocyanine green reduce bile duct injuries and conversions to open surgery during laparoscopic or robotic cholecystectomy? - A meta-analysis

BACKGROUND

Bile duct injury and conversion-to-open-surgery rates remain unacceptably high during laparoscopic and robotic cholecystectomy. In a recently published randomized clinical trial, using near-infrared fluorescent cholangiography with indocyanine green intraoperatively markedly enhanced biliary-structure visualization. Our systematic literature review compares bile duct injury and conversion-to-open-surgery rates in patients undergoing laparoscopic or robotic cholecystectomy with versus without near-infrared fluorescent cholangiography.

METHODS

A thorough PubMed search was conducted to identify randomized clinical trials and nonrandomized clinical trials with ≥100 patients. Because all near-infrared fluorescent cholangiography studies were published since 2013, only studies without near-infrared fluorescent cholangiography published since 2013 were included for comparison. Incidence estimates, weighted and unweighted for study size, were adjusted for acute versus chronic cholecystitis, and for robotic versus laparoscopic cholecystectomy and are reported as events/10,000 patients. All studies were assessed for bias risk and high-risk studies excluded.

RESULTS

In total, 4,990 abstracts were reviewed, identifying 5 near-infrared fluorescent cholangiography studies (3 laparoscopic cholecystectomy/2 robotic cholecystectomy; n = 1,603) and 11 not near-infrared fluorescent cholangiography studies (5 laparoscopic cholecystectomy/4 robotic cholecystectomy/2 both; n = 5,070) for analysis. Overall weighted rates for bile duct injury and conversion were 6 and 16/10,000 in near-infrared fluorescent cholangiography patients versus 25 and 271/10,000 in patients without near-infrared fluorescent cholangiography. Among patients undergoing laparoscopic cholecystectomy, bile duct injuries, and conversion rates among near-infrared fluorescent cholangiography versus patients without near-infrared fluorescent cholangiography were 0 and 23/10,000 versus 32 and 255/10,000, respectively. Bile duct injury rates were low with robotic cholecystectomy with and without near-infrared fluorescent cholangiography (12 and 8/10,000), but there was a marked reduction in conversions with near-infrared fluorescent cholangiography (12 vs 322/10,000).

CONCLUSION

Although large comparative trials remain necessary, preliminary analysis suggests that using near-infrared fluorescent cholangiography with indocyanine green intraoperatively sizably decreases bile duct injury and conversion-to-open-surgery rates relative to cholecystectomy under white light alone.

Development of Sentinel LN Imaging with a Combination of HAase Based on a Comprehensive Analysis of the Intra-lymphatic Kinetics of LPs

The sentinel lymph node (LN) is the first LN to which lymph fluid flows from tumor tissue. We identified the key parameters of liposomes (LPs) that affect their accumulation in regional (primary) LNs with minimum leakage to its connecting (secondary) LNs by a comprehensive analysis of the LN-to-LN trafficking of LPs with various surface charges and various sizes. We used a lymphatic flow-modified (LFM) mouse that allows for the chronological analysis of inguinal (primary) LN-to-axillary (secondary) LN at the body surface. As a result, the anionic medium-sized LPs (130 nm on average) exhibited the highest accumulation in the primary LNs. A mechanism-based analysis revealed that CD169-positive macrophages in LNs were the dominant cell population that captures anionic LPs. Sentinel LN imaging was also performed by the intratumoral injection of fluorescent medium-sized anionic LPs using a breast cancer orthotopic model. In comparison with the typically used contrast agent indocyanine green, the anionic LPs were detected in sentinel LNs with a high sensitivity. Additionally, the co-injection of hyaluronidase significantly improved the sensitivity of detection of the fluorescent LPs in sentinel LNs. In conclusion, medium-sized anionic LPs combined with hyaluronidase represents a potent strategy for investigating sentinel LNs.

[Analysis of lymphatic drainage pathways using infrared fluorescence in patients with lung cancer]

OBJECTIVE

To develop a method for analysis of lymphatic drainage pathways from the lobe of the lung affected by non-small cell lung cancer (NSCLC) using infrared fluorescence.

MATERIAL AND METHODS

A study enrolled patients with NSCLC who underwent anatomic resection of the lung with systematic lymph node dissection and preliminary intraoperative peritumoral injection of indocyanine green conjugate with human albumin. Registration of fluorescence in regional lymph nodes (LN) was carried out immediately after excision of specimen using the FLUM-808 instrumental system.

RESULTS

Infrared fluorescence was observed in 117 hilar and mediastinal lymph nodes from 43 patients (2.7 nodes per a patient). Comparison of localization of fluorescent LN with localization of tumor in various lobes established significant variability of lymphatic drainage pathways.

CONCLUSION

The developed method of infrared fluorescent evaluation of lymphatic drainage in patients with NSCLC confirms the necessity of systematic lymph node dissection for adequate staging.

Use of indocyanine green fluorescence compared to radioisotope for sentinel lymph node biopsy in early-stage breast cancer: systematic review and meta-analysis

BACKGROUND

In early-stage breast cancer, indocyanine green (ICG)-fluorescence based sentinel lymph node (SLN) detection is being considered. This is a meta-analysis of SLN detection rates and sensitivity of ICG-fluorescence compared to radioisotope (RI), to evaluate its clinical applicability.

DATA SOURCES

Systematic review of full-text articles from PubMed and Scopus, of women with early breast cancer who underwent SLN mapping using ICG and RI concurrently was performed. The meta-analysis was performed using the Mantel-Haenszel method.

RESULTS

2301 patients from 19 studies were included. No significant difference was observed between ICG and RI for SLN detection (OR0.90,95%CI0.66-1.24) or sensitivity (OR1.23,95%CI0.73-2.05) with heterogeneity between studies (I² = 58%,P = 0.003). Sensitivity of dual mapping (ICG + RI) was significantly better compared to single mapping with RI (OR3.69,95%CI1.79-7.62) or ICG (OR3.32,95%CI1.52-7.24) alone with no heterogeneity between studies (I² = 0%,P = 0.004).

CONCLUSION

ICG-fluorescence could complement RI method or provide alternative in centers with poor accessibility to RI lymphoscintigraphy.

Image-Guided Pediatric Surgery Using Indocyanine Green (ICG) Fluorescence in Laparoscopic and Robotic Surgery

Background: Indocyanine green (ICG)-guided near-infrared fluorescence (NIRF) has been recently adopted in pediatric minimally invasive surgery (MIS). This study aimed to report our experience with ICG-guided NIRF in pediatric laparoscopy and robotics and evaluate its usefulness and technique of application in different pediatric pathologies. Methods: ICG technology was adopted in 76 laparoscopic and/or robotic procedures accomplished in a single division of pediatric surgery over a 24-month period (January 2018-2020): 40 (37 laparoscopic, three robotic) left varicocelectomies with intra-operative lymphography; 13 (10 laparoscopic, three robotic) renal procedures: seven partial nephrectomies, three nephrectomies, and three renal cyst deroofings; 12 laparoscopic cholecystectomies; five robotic tumor excisions; three laparoscopic abdominal lymphoma excisions; three thoracoscopic procedures: two lobectomies and one lymph node biopsy for suspected lymphoma. The ICG solution was administered into a peripheral vein in all indications except for varicocele and lymphoma in which it was, respectively, injected into the testis body or the target organ. Regarding the timing of the administration, the ICG solution was administered intra-operatively in all indications except for cholecystectomy in which the ICG injection was performed 15-18 h before surgery. Results: No conversions to open or laparoscopy occurred. No adverse and allergic reactions to ICG or other postoperative complications were reported. Conclusions: Based upon our 2 year experience, we believe that ICG-guided NIRF is a very useful tool in pediatric MIS to perform a true imaged-guided surgery, allowing an easier identification of anatomic structures and an easier surgical performance in difficult cases. The most common applications in pediatric surgery include varicocele repair, difficult cholecystectomy, partial nephrectomy, lymphoma, and tumors excision but further indications will be soon discovered. ICG-enhanced fluorescence was technically easy to apply and safe for the patient reporting no adverse reactions to the product. The main limitation is represented by the specific equipment needed to apply ICG-guided NIRF in laparoscopic procedures, that is not available in all centers whereas the ICG system Firefly® is already integrated into the robotic platform.

The Turkish SentiMAG feasibility trial: preliminary results

BACKGROUND

Sentinel node biopsy (SNB) is the standard of care for staging of the clinically and radiologically negative axillary lymph nodes in breast cancer patients. Sentinel node biopsy, with using Technetium-sulphur colloid (99 m Tc) alone or with blue dye is standard technique for evaluating axillary lymph nodes. This technique has drawbacks such as radiation exposure. Superparamagnetic iron oxide nanoparticles (SPIO) can represent a valid option for SNB. In this study; we tried to evaluate feasibility of new magnetic technique in Turkish early breast cancer patients.

MATERIAL AND METHODS

The study sample consists of 143 women affected by early breast carcinoma with clinically negative axillary lymph nodes. Sentinel node localization was performed using magnetic technique. Detection rate of magnetic technique was calculated and postoperative complications were assessed.

RESULTS

Results are based on 104 patients. Sentinel node identification rate was 99% (103/104, 95% CI 0.97-1.01) for magnetic technique. A median of two SNs per patient was removed. Major adverse reaction was the permanent skin coloration (7.1%).

CONCLUSIONS

The magnetic technique is a feasible method for detecting SN in breast cancer patients with minimal adverse effects. Magnetic technique may be alternative to standard technique especially in breast units, where nuclear medicine unit is not available.

Evaluation of lymph node metastasis in a rabbit tumor model: correlations between contrast-enhanced ultrasound and pathologic findings

Purpose

The purpose of this study was to evaluate the ability of contrast-enhanced ultrasonography (CEUS) with microbubbles to detect metastatic lymph nodes (LNs) for treatment planning and prognosis.

Methods

For the metastatic LN model, ground VX₂ tumor tissues were injected subcutaneously in 12 rabbits, just below the right hind limb. The rabbits were classified into three groups based on the LN area: group A (n=4, >1.9 cm² ), group B (n=4, 1-1.9 cm² ), and group C (n=4, <1 cm² ). The LNs were monitored on CEUS for 10 seconds after injecting 2.5 mL of microbubbles. The percent area of metastatic LNs was calculated on pathologic images and compared with CEUS images.

Results

In group A, the mean percent area of metastasis was 40.7%±19.4%. In all cases of metastasis, round-shaped perfusion defects were clearly observed in CEUS images. The metastatic areas were strongly correlated with pathologic findings. The mean percent area in group B was 21.5%±14.4%. The CEUS findings showed multiple nodular perfusion defects, clearly revealing the metastatic areas. In group B, the CEUS and pathologic findings were concordant for three of the four cases. The mean percent area in group C was 9.1%±6.4%. However, in this group, CEUS only detected a small perfusion defect in one case.

Conclusion

CEUS has the potential to depict characteristic imaging features of metastatic LNs but still has limitations in early detection.