Fluorescence navigation with indocyanine green for detecting sentinel lymph nodes in breast cancer

Indocyanine green detects sentinel lymph nodes in early breast cancer

Objective

To explore the clinical value of indocyanine green (ICG) for the fluorescence-guided detection of sentinel lymph nodes (SLNs) during sentinel lymph node biopsy (SLNB) in patients with early breast cancer.

Methods

This retrospective study included female patients with breast cancer. Patients were administered methylene blue and ICG using standard techniques. All SLNs that were collected during surgery were submitted for pathological examination. SLNs were defined as those that were either fluorescent, blue, fluorescent and blue or palpably suspicious. Surgical complications, axillary recurrence, distant metastasis and overall survival rates were observed postoperatively.

Results

A total of 60 patients were enrolled in the study. The fluorescence detection rate of SLNs was 100% (n = 177), with a mean of 2.95 SLNs per patient. The methylene blue staining rate was 88.3% (n = 106), with a mean of 1.77 SLNs per patient. Pathological assessment of intraoperative frozen specimens revealed SLN metastases in 10 patients, who immediately underwent axillary lymph node dissection. No patient had axillary recurrence or distant metastases, with a survival rate of 100%. Patients who underwent SLNB showed good appearance in the axillary wound, with no limited shoulder joint abduction and upper limb oedema.

Conclusion

Fluorescence-guided SLNB has several advantages and is suitable for clinical application.

Fluorescent Versus Radioguided Lymph Node Mapping in Bladder Cancer

INTRODUCTION

The aim of the study was to compare 2 methods of the sentinel lymph node biopsy (SLNB) procedure in bladder cancer: we applied technetium radiocolloid (RadCol) detected by a gamma ray detection probe, and indocyanine green (ICG) detected by a near-infrared fluorescent (NIRF) camera.

MATERIAL AND METHODS

The SLNB was performed on 50 patients using the RadCol and the ICG, followed by a lymphadenectomy and a pathologic examination.

RESULTS

In the analyzed group of 47 patients (3 patients were excluded owing to the lack of lymphatic drainage from the tumor), the SLNB was performed using the 2 methods. The ICG with a NIRF-guided camera detected all sentinel lymph nodes (SLNs) in 46 cases, whereas RadCol detected them in 45 cases. In 12 (25.6%) of 47 patients, the ICG-fluorescent method revealed more SLNs than the RadCol method. In 8 (17%) patients, the SLNs revealed in the ICG fluorescence were metastatic. In 3 (6.4%) patients, we found SLNs outside the standard lymphadenectomy template, but a histopathologic examination showed they were negative for cancer. In 3 (6.4%) patients, the SLNs detected by both methods were negative for cancer, but other resected lymph nodes revealed metastases.

CONCLUSION

Our study shows that SLNB procedure with the RadCol or the ICG method is useful for the evaluation of lymph nodes in bladder cancer. The new ICG fluorescent technique with a NIRF camera system is safe, enables live view of the results of the procedure, and does not create additional costs. However, it highlights more lymph nodes than the radioactive method.

Sentinel lymph node biopsy using indocyanine green fluorescence in early-stage breast cancer: a meta-analysis

Sentinel lymph node (SLN) biopsy using indocyanine green (ICG) fluorescence is safe and has a high detection rate for SLNs. However, the results of this novel technique are heterogeneous. The objective of this meta-analysis was to evaluate the diagnostic performance of the ICG fluorescence method compared with the standard radioisotope (RI) method. All eligible studies were identified from 2005 through 2015. A proportion meta-analysis was performed using a fixed effects and/or random effects model based on the study heterogeneity. A total of 12 studies met the inclusion criteria and included 1736 women. There was no significant difference between ICG fluorescence and RI for SLN detection using either the fixed effects model [odds ratio (OR) 1.29, 95% confidence interval (CI) 0.87-1.90] or the random effects model (OR 1.32, 95% CI 0.54-3.18). There were seven studies reporting the detection rate for tumor-positive SLN. The ICG fluorescence method was significantly better than the RI method in the fixed effects model (OR 1.87, 95% CI 1.00-3.49) for staging axilla. However, there was no difference in the random effects model (OR 1.90, 95% CI 0.74-4.86). There was study outcome heterogeneity for the detection of SLN but not for tumor-positive SLN. There was no publication bias observed in the studies included. The ICG fluorescence method has valid diagnostic performance for SLN detection and shows a trend toward better axilla staging compared with the RI method. ICG fluorescence is a useful alternative to RI for SLN biopsy.

Liver tumor boundaries identified intraoperatively using real-time indocyanine green fluorescence imaging

Purpose

Clear delineation between tumors and normal tissues is ideal for real-time surgical navigation imaging. We investigated applying indocyanine green (ICG) fluorescence imaging navigation using an intraoperative administration method in liver resection.

Methods

Fifty patients who underwent liver resection were divided into two groups based on clinical situation and operative purpose. In group I, sizes of superficial liver tumors were determined; tiny tumors were identified. In group II, the liver resection margin was determined; real-time navigation was performed. ICG was injected intravenously at the beginning of the operation; the liver surface was observed with a photodynamic eye (PDE).

Results

Liver resection margins were determined using PDE. Fluorescence contrast between normal liver and tumor tissues was obvious in 32 of 35 patients. A boundary for half the liver or specific liver segments was determined in nine patients by examining the portal vein anatomy after ICG injection. Eight small tumors not observed preoperatively were detected; the smallest was 2 mm.

Conclusions

ICG fluorescence imaging navigation is a promising, simple, and safe tool for routine real-time intraoperative imaging during hepatic resection and clinical exploration in hepatocellular carcinoma, enabling high sensibility for identifying liver resection margins and detecting tiny superficial tumors.

Patterns of clinical practice for sentinel lymph node biopsy in women with node-negative breast cancer: the results of a national survey in Japan

PURPOSE

Sentinel lymph node (SLN) biopsy is now accepted as the standard of care for axillary staging in women with node-negative breast cancer. Currently, dye, radioisotope (RI), and fluorescence indocyanine green (fICG) are tracers available. Importance of these three tracers has been recognized for SLN biopsy but the trend for SLN mapping has not been reported. Aim of this national wide survey was to evaluate practice patterns of SLN biopsy in Japan.

METHODS

This survey was conducted to examine the clinical practice of SLN biopsy in centers where one or more Japanese Breast Cancer Society (JBCS) board-certified surgeons practice breast cancer care. Their responses were recorded from 1 to 30 Oct 2014 and received by mail or fax in Japan. The questionnaire included three items: the number of breast cancer patients treated per year, the number of SLN biopsy procedures in a single year, and the methods for SLN detection.

RESULTS

A total of 412 responses excluding the 63 centers that do not perform the surgery were analyzed. Out of them, 206 (50 %) centers had a gamma probe, 118 (29 %) had an NIR fluorescence imaging system, and both were available at 49 (12 %) of the centers. Neither RI nor fICG was available in 137 (33 %). The dye method was preferentially used in private hospitals. In 412 centers, a total of 36,221 patients underwent SLN biopsy per year and 23,038 (64 %) received radioactive tracer. fICG was co-applied with RI in 83 and 13 % of patients, respectively. Single mapping with RI alone was used in only 4 % of patients. The non-radioactive method was used for routine SLN biopsy in 13,183 (36 %) patients [8533 (24 %) for dye alone and 4650 (12 %) for fICG alone].

CONCLUSIONS

A radioactive tracer was used in 64 % of women with early breast cancer for SLN biopsy while approximately 24 % received dye alone, which was especially prevalent in PHs. The fICG was used in only 12 % as a non-radioactive method but incentive package for fICG by national health insurance plan could increase the number of NIR imaging systems and improve the sensitivity for SLN biopsy in Japan.

Clinical application of indocyanine green-fluorescence imaging during hepatectomy

In hepatobiliary surgery, the fluorescence and bile excretion of indocyanine green (ICG) can be used for real-time visualization of biological structure. Fluorescence cholangiography is used to obtain fluorescence images of the bile ducts following intrabiliary injection of 0.025-0.5 mg/mL ICG or intravenous injection of 2.5 mg ICG. Recently, the latter technique has been used in laparoscopic/robotic cholecystectomy. Intraoperative fluorescence imaging can be used to identify subcapsular hepatic tumors. Primary and secondary hepatic malignancy can be identified by intraoperative fluorescence imaging using preoperative intravenous injection of ICG through biliary excretion disorders that exist in cancerous tissues of hepatocellular carcinoma (HCC) and in non-cancerous hepatic parenchyma around adenocarcinoma foci. Intraoperative fluorescence imaging may help detect tumors to be removed, especially during laparoscopic hepatectomy, in which visual inspection and palpation are limited, compared with open surgery. Fluorescence imaging can also be used to identify hepatic segments. Boundaries of hepatic segments can be visualized following injection of 0.25-2.5 mg/mL ICG into the portal veins or by intravenous injection of 2.5 mg ICG following closure of the proximal portal pedicle toward hepatic regions to be removed. These techniques enable identification of hepatic segments before hepatectomy and during parenchymal transection for anatomic resection. Advances in imaging systems will increase the use of fluorescence imaging as an intraoperative navigation tool that can enhance the safety and accuracy of open and laparoscopic/robotic hepatobiliary surgery.

Near-infrared indocyanine dye permits real-time characterization of both venous and lymphatic circulation

We investigated the optical properties of a near-infrared (NIR) fluorochrome, di-β-cyclodextrin-binding indocyanine derivative (TK-1), and its pharmacokinetic differences with indocyanine green (ICG). TK-1 was designed to have hydrophilic cyclodextrin molecules and, thus, for higher water solubility and smaller particle sizes than the plasma protein-bound ICG. We compared optical properties such as the absorption and fluorescence spectra, quantum yield, and photostability between both dyes in vitro. In addition, we subcutaneously injected a 1 mM solution of TK-1 or ICG into the hind footpad of rats and observed real-time NIR fluorescence intensities in their femoral veins and accompanying lymphatics at the exposed groin site to analyze the dye pharmacokinetics. These optical experiments demonstrated that TK-1 has high water solubility, a low self-aggregation tendency, and high optical and chemical stabilities. Our in vivo imaging showed that TK-1 was transported via peripheral venous flow and lymphatic flow, whereas ICG was drained only through lymphatics. The results of this study showed that lymphatic and venous transport can be differentially regulated and is most likely influenced primarily by particle size, and that TK-1 can enable real-time NIR fluorescence imaging of whole fluids and solute movement via both microvessels and lymphatics, which conventional ICG cannot achieve.

Review of fluorescence guided surgery systems: identification of key performance capabilities beyond indocyanine green imaging

There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here.

Optical imaging probes in oncology

Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management.Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation.The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed.

Benchtop and Animal Validation of a Projective Imaging System for Potential Use in Intraoperative Surgical Guidance

We propose a projective navigation system for fluorescence imaging and image display in a natural mode of visual perception. The system consists of an excitation light source, a monochromatic charge coupled device (CCD) camera, a host computer, a projector, a proximity sensor and a Complementary metal-oxide-semiconductor (CMOS) camera. With perspective transformation and calibration, our surgical navigation system is able to achieve an overall imaging speed higher than 60 frames per second, with a latency of 330 ms, a spatial sensitivity better than 0.5 mm in both vertical and horizontal directions, and a projection bias less than 1 mm. The technical feasibility of image-guided surgery is demonstrated in both agar-agar gel phantoms and an ex vivo chicken breast model embedding Indocyanine Green (ICG). The biological utility of the system is demonstrated in vivo in a classic model of ICG hepatic metabolism. Our benchtop, ex vivo and in vivo experiments demonstrate the clinical potential for intraoperative delineation of disease margin and image-guided resection surgery.

Blood flow speed of the gastric conduit assessed by indocyanine green fluorescence: New predictive evaluation of anastomotic leakage after esophagectomy

Anastomotic leakage is considered as an independent risk factor for postoperative mortality after esophagectomy, and an insufficient blood flow in the reconstructed conduit may be a risk factor of anastomotic leakage. We investigated the clinical significance of blood flow visualization by indocyanine green (ICG) fluorescence in the gastric conduit as a means of predicting the leakage of esophagogastric anastomosis after esophagectomy.Forty patients who underwent an esophagectomy with gastric conduit reconstruction were prospectively investigated. ICG fluorescence imaging of the gastric conduit was detected by a near-infrared camera system during esophagectomy and correlated with clinical parameters or surgical outcomes.In 25 patients, the flow speed of ICG fluorescence in the gastric conduit wall was simultaneous with that of the greater curvature vessels (simultaneous group), whereas in 15 patients this was slower than that of the greater curvature vessels (delayed group). The reduced speed of ICG fluorescence stream in the gastric conduit wall was associated with intraoperative blood loss (P = 0.008). Although anastomotic leakage was not found in the simultaneous group, it occurred in 7 patients of the delayed group (P < 0.001). A flow speed of ICG fluorescence in the gastric conduit wall of 1.76 cm/s or less was determined by a receiver operating characteristic (ROC) curve, identified as a significant independent predictor of anastomotic leakage after esophagectomy (P = 0.004).This preliminary study demonstrates that intraoperative evaluation of blood flow speed by ICG fluorescence in the gastric conduit wall is a useful means to predict the risk of anastomotic leakage after esophagectomy.

A Wearable Goggle Navigation System for Dual-Mode Optical and Ultrasound Localization of Suspicious Lesions: Validation Studies Using Tissue-Simulating Phantoms and an Ex Vivo Human Breast Tissue Model

Surgical resection remains the primary curative treatment for many early-stage cancers, including breast cancer. The development of intraoperative guidance systems for identifying all sites of disease and improving the likelihood of complete surgical resection is an area of active ongoing research, as this can lead to a decrease in the need of subsequent additional surgical procedures. We develop a wearable goggle navigation system for dual-mode optical and ultrasound imaging of suspicious lesions. The system consists of a light source module, a monochromatic CCD camera, an ultrasound system, a Google Glass, and a host computer. It is tested in tissue-simulating phantoms and an ex vivo human breast tissue model. Our experiments demonstrate that the surgical navigation system provides useful guidance for localization and core needle biopsy of simulated tumor within the tissue-simulating phantom, as well as a core needle biopsy and subsequent excision of Indocyanine Green (ICG)—fluorescing sentinel lymph nodes. Our experiments support the contention that this wearable goggle navigation system can be potentially very useful and fully integrated by the surgeon for optimizing many aspects of oncologic surgery. Further engineering optimization and additional in vivo clinical validation work is necessary before such a surgical navigation system can be fully realized in the everyday clinical setting.

Lymphosome concept: Anatomical study of the lymphatic system

The gross anatomical study of the lymphatic system in humans and animals has been suspended for almost 100 years. This article introduces the author's technique for investigating the lymphatic system using the concept of the lymphosome. In revisiting the anatomical study of the lymphatic system, our updated knowledge can potentially be utilized either to reassure surgeons about their current procedures in the surgical management of cancers and lymphedema or assist them to refine them. J. Surg. Oncol. 2017;115:13-17. © 2016 Wiley Periodicals, Inc.

Indocyanine Green Fluorescence Navigation Thoracoscopic Metastasectomy for Pulmonary Metastasis of Hepatocellular Carcinoma

Indocyanine green can selectively accumulate in primary hepatocellular carcinoma (HCC) and extrahepatic metastases. We report a patient who underwent resection of pulmonary metastasis of HCC using a thoracoscopic near-infrared imaging system and fluorescent navigation surgery. A 66-year-old man with suspicion of pulmonary metastasis of HCC was referred to our hospital. Indocyanine green was injected intravenously at a dose of 0.5 mg/kg body weight, 20 h before thoracoscopic surgery. An endoscopic indocyanine green near-infrared fluorescence imaging system showed clear blue fluorescence, indicating pulmonary metastasis of HCC in a lingular segment. We performed wide wedge resection using the fluorescence image for navigation to confirm the surgical margins. The specimen was histologically confirmed as a pulmonary metastasis of HCC. In conclusion, thoracoscopic indocyanine green near-infrared fluorescence imaging for pulmonary metastases of HCC is useful in identifying tumor locations and ensuring resection margins.

Indocyanine green-based fluorescent angiography in breast reconstruction

BACKGROUND

Fluorescent angiography (FA) has been useful for assessing blood flow and assessing tissue perfusion in ophthalmology and other surgical disciplines for decades. In plastic surgery, indocyanine green (ICG) dye-based FA is a relatively novel imaging technology with high potential in various applications. We review the various FA detector systems currently available and critically appraise its utility in breast reconstruction.

METHODS

A review of the published English literature dating from 1950 to 2015 using databases, such as PubMed, Medline, Web of Science, and EMBASE was undertaken.

RESULTS

In comparison to the old fluorescein dye, ICG has a superior side effect profile and can be accurately detected by various commercial devices, such as SPY Elite (Novadaq, Canada), FLARE (Curadel LLC, USA), PDE-Neo (Hamamatsu Photonics, Japan), Fluobeam 800 (Fluoptics, France), and IC-View (Pulsion Medical Systems AG, Germany). In breast reconstruction, ICG has established as a safer, more accurate tracer agent, in lieu of the traditional blue dyes, for detection of sentinel lymph nodes with radioactive isotopes ((99m)-Technetium). In prosthesis-based breast reconstruction, intraoperative assessment of the mastectomy skin flap to guide excision of hypoperfused areas translates to improved clinical outcomes. Similarly, in autologous breast reconstructions, FA can be utilized to detect poorly perfused areas of the free flap, evaluate microvascular anastomosis for patency, and assess SIEA vascular territory for use as an alternative free flap with minimal donor site morbidity.

CONCLUSIONS

ICG-based FA is a novel, useful tool for various applications in breast reconstruction. More studies with higher level of evidence are currently lacking to validate this technology.

Tumor lymphangiogenesis and new drug development

Traditionally, tumor-associated lymphatic vessels have been regarded as passive by-standers, serving simply as a drainage system for interstitial fluid generated within the tumor. However, with growing evidence that tumors actively induce lymphangiogenesis, and that the number of lymphatic vessels closely correlates with metastasis and clinical outcome in various types of cancer, this picture has changed dramatically in recent years. Tumor-associated lymphatic vessels have now emerged as a valid therapeutic target to control metastatic disease, and the first specific anti-lymphangiogenic drugs have recently entered clinical testing. Furthermore, we are just beginning to understand the whole functional spectrum of tumor-associated lymphatic vessels, which not only concerns transport of fluid and metastatic cells, but also includes the regulation of cancer stemness and specific inhibition of immune responses, opening new venues for therapeutic applications. Therefore, we predict that specific targeting of lymphatic vessels and their function will become an important tool for future cancer treatment.

Evaluation of intraoperative fluorescence imaging-guided surgery in cancer-bearing dogs: a prospective proof-of-concept phase II study in 9 cases

The objective was to prospectively evaluate the application of intraoperative fluorescence imaging (IOFI) in the surgical excision of malignant masses in dogs, using a novel lipid nanoparticle contrast agent. Dogs presenting with spontaneous soft-tissue sarcoma or subcutaneous tumors were prospectively enrolled. Clinical staging and whole-body computed tomography (CT) were performed. All the dogs received an intravenous injection of dye-loaded lipid nanoparticles, LipImage 815. Wide or radical resection was realized after CT examination. Real-time IOFI was performed before skin incision and after tumor excision. In cases of radical resection, the lymph nodes (LNs) were imaged. The margin/healthy tissues fluorescence ratio or LN/healthy tissues fluorescence ratio was measured and compared with the histologic margins or LN status. Nine dogs were included. Limb amputation was performed in 3 dogs, and wide resection in 6. No adverse effect was noted. Fluorescence was observed in all 9 of the tumors. The margins were clean in 5 of 6 dogs after wide surgical resection, and the margin/healthy tissues fluorescence ratio was close to 1.0 in all these dogs. Infiltrated margins were observed in 1 case, with a margin/healthy tissues fluorescence ratio of 3.2. Metastasis was confirmed in 2 of 3 LNs, associated with LN/healthy tissues fluorescence ratios of 2.1 and 4.2, whereas nonmetastatic LN was associated with a ratio of 1.0. LipImage 815 used as a contrast agent during IOFI seemed to allow for good discrimination between tumoral and healthy tissues. Future studies are scheduled to evaluate the sensitivity and specificity of IOFI using LipImage 815 as a tracer.

Imaging methods for the local lymphatic system of the axilla in early breast cancer in patients qualified for sentinel lymph node biopsy

Breast cancer is the most common malignancy in women in well-developed countries. Despite a constant increase in its incidence, the percentage of patients diagnosed with the disease in the non-invasive stage is also rising. This allows more frequently for the use of breast-preserving surgical techniques, involving the breast and the regional lymphatic system.

According to current guidelines of expert panels and research societies, the recommended method of identifying the sentinel lymph node is the use of an isotope marker with a dye (a combined isotope and dye method). Cooperation with a nuclear medicine unit is essential (performing a preoperative lymphoscintigraphic scan to identify the lymphatic drainage basin and sentinel lymph node). In the case of smaller centers treating breast cancer, it can be associated with a number of difficulties, including organizational ones, and also increasing general treatment costs.

A possible solution to these problems is to use alternative techniques of visualizing the sentinel lymph node, which do not require a radiotracer. In this paper we discuss the currently available methods of mapping the lymphatic system of the axillary region in patients with early breast cancer. The review is limited to reporting on methods of proven (based on clinical research) high diagnostic value.

A systematic review and meta-analyses of sentinel lymph node identification in breast cancer and melanoma, a plea for tracer mapping

PURPOSE

Sentinel lymph node biopsy (SLNB) has become a widely accepted staging procedure for both breast carcinoma and melanoma. The aim of our study was to systematically review different SLNB techniques and perform a meta-analysis for corresponding identification and false-negative rates.

METHODS

A systematic review of the literature on SLNB in patients with early stage breast carcinoma and melanoma was performed. Only original study groups were included. The SLN identification rate and false negative rate were pooled for patients with breast carcinoma or melanoma according to radiocolloid tracer, blue dye, indocyanine green (ICG), or a combination of a radiocolloid tracer with blue dye or ICG.

RESULTS

Between 1992 and 2012, a total of 154 studies (88 breast carcinoma and 66 melanoma) were reported that met our eligibility criteria. These studies included a total of 44,172 patients. The pooled SLN identification rate in breast carcinoma and melanoma patients using solely blue dye was 85% (range: 65-100%) and 84% (range: 59-100%), while for radiocolloid alone it was 94% (range: 67-100%) and 99% (range: 83-100%), respectively. Using a combination of radiocolloid and blue, identification rates were 95% (range 94-95%) and 98% (range: 98-98%).

CONCLUSIONS

The current meta-analysis provides data that favors the use of radiocolloid or radiocolloid combined with a blue dye for SLN identification. Performing SLNB with radiocolloid alone is the technique of choice for experienced surgeons, since blue dye has multiple disadvantages. SLNB using ICG as a fluorescent dye seems a promising technique for the near future.

Intraoperative Spectroscopy with Ultrahigh Sensitivity for Image-Guided Surgery of Malignant Brain Tumors

Intraoperative cancer imaging and fluorescence-guided surgery have attracted considerable interest because fluorescence signals can provide real-time guidance to assist a surgeon in differentiating cancerous and normal tissues. Recent advances have led to the clinical use of a natural fluorophore called protoporphyrin IX (PpIX) for image-guided surgical resection of high-grade brain tumors (glioblastomas). However, traditional fluorescence imaging methods have only limited detection sensitivity and identification accuracy and are unable to detect low-grade or diffuse infiltrating gliomas (DIGs). Here we report a low-cost hand-held spectroscopic device that is capable of ultrasensitive detection of protoporphyrin IX fluorescence in vivo, together with intraoperative spectroscopic data obtained from both animal xenografts and human brain tumor specimens. The results indicate that intraoperative spectroscopy is at least 3 orders of magnitude more sensitive than the current surgical microscopes, allowing ultrasensitive detection of as few as 1000 tumor cells. For detection specificity, intraoperative spectroscopy allows the differentiation of brain tumor cells from normal brain cells with a contrast signal ratio over 100. In vivo animal studies reveal that protoporphyrin IX fluorescence is strongly correlated with both MRI and histological staining, confirming that the fluorescence signals are highly specific to tumor cells. Furthermore, ex vivo spectroscopic studies of excised brain tissues demonstrate that the hand-held spectroscopic device is capable of detecting diffuse tumor margins with low fluorescence contrast that are not detectable with current systems in the operating room. These results open new opportunities for intraoperative detection and fluorescence-guided resection of microscopic and low-grade glioma brain tumors with invasive or diffusive margins.

Indocyanine-green-loaded microbubbles for localization of sentinel lymph node using near-infrared fluorescence/ultrasound imaging: a feasibility study

Current strategies for sentinel lymph node (SLN) biopsy to detect cancer metastasis have some limitations such as the associated radiation exposure and high false-negative rates due to dye particles through the true SLNs to contiguous LNs.

[Focus on methods for detection of sentinel nodes in breast cancer]

The sentinel node procedure (GS) is the recommended technique for axillary surgical exploration in localized breast cancer with no clinical or radiological lymph node involvement. This surgical technique is based on a dual isotope and colorimetric detection. Although it allows a significant reduction in morbidity compared to axillary dissection (CA), this procedure induces a number of organizational constraints, in particular for the radioisotope injection. Specially for this reason, other GS methods have emerged in recent years, some of which appear promising (detection by fluorescence and magnetic iron). The objective of this paper was to carry out a synthesis of the reference method of detection (radioisotope) GS and analyze the recent literature on new detection methods.

Indocyanine green fluorescence mapping for sentinel lymph node biopsy in early breast cancer

INTRODUCTION

A recent feasibility study (ICG-10) has confirmed high sensitivity of ICG fluorescence mapping for sentinel SLN detection in early breast cancer with 95% of nodes both blue and fluorescent. This follow-on study has specifically evaluated a combination of ICG and blue dye for SLN localization.

METHODS

Fifty consecutive patients (49 female; 1 male) with unilateral clinically node negative invasive (37) and non-invasive (13) breast cancer underwent SLN biopsy with blue dye and ICG. Median patient age was 48 years and median invasive tumour size 19 mm for primary surgical patients. All patients had a normal pre-operative axillary ultrasound. Nodal and procedural detection rates were calculated for ICG alone and in combination with blue dye.

RESULTS

A total of 87 nodes were retrieved with an average nodal count of 1.8 per patient (range 1-4). Eighty four nodes were blue and fluorescent and 3 fluorescent only. Nodal detection rates for ICG alone and combined with blue dye were 100% (87/87) and 96% (84/87) respectively. Metastases were present in 18 nodes (all blue and fluorescent) with 10 patients node positive overall (20%). The procedural detection rate for blue dye and ICG was 96% (48/50) and 2 patients had fluorescent only nodes which were deemed sentinel (4%).

CONCLUSION

Fluorescent imaging with ICG is a sensitive, valuable and safe method for SLN biopsy. A combination of blue dye and ICG is useful dual approach when radioisotope is unavailable. ICG has the potential to be a sole tracer agent with improved patient convenience and costs.

Sentinel node biopsy using indocyanine green in oral/oropharyngeal cancer

BACKGROUNDS

Radioactive tracer-based detection has been proposed as a standard procedure in identifying sentinel nodes for cN0 oral/oropharyngeal carcinoma. However, access to radioactive isotopes may be limited in some surgical centers, and there is potential risk of the radioactive tracers to the operators. This study was designed to evaluate the feasibility of near-infrared fluorescence imaging with indocyanine green combined with blue dye mapping in sentinel node biopsy for cN0 oral/oropharyngeal carcinoma.

METHODS

Twenty-six cases of previously untreated oral/oropharyngeal carcinoma staged cT1-2N0M0 were enrolled in this study. One milliliter of indocyanine green (5 mg/ml) and 1.5 ml of methylene blue (1 mg/ml) were injected sequentially around the primary tumor in a four-quadrant pattern before skin incision. After elevation of the platysma flap and posterior retraction of the sternocleidomastoid muscle, fluorescence images were taken with a near-infrared detector, with special attention paid to any blue-dyed lymph nodes. Lymph nodes identified first with fluorescent hot spots with or without blue dye were defined as sentinel nodes, and they were harvested and sent for pathologic study.

RESULTS

Sentinel nodes were successfully harvested in all 26 cases. The number of sentinel nodes (SNs) per case varied from 1 to 9, with an average of 3.4. Routine pathology demonstrated occult metastasis exclusively in SNs in four cases (15.4 %). No tracer-associated side effects occurred in this series.

CONCLUSIONS

Near-infrared imaging using indocyanine green combined with methylene blue mapping is a feasible and reliable new method for SN biopsy in cN0 oral/oropharyngeal carcinoma.

Luminescence-based Imaging Approaches in the Field of Interventional Molecular Imaging

Luminescence imaging-based guidance technologies are increasingly gaining interest within surgical and radiologic disciplines. Their promise to help visualize molecular features of disease in real time and with microscopic detail is considered desirable. Integrating luminescence imaging with three-dimensional radiologic- and/or nuclear medicine-based preinterventional imaging may overcome limitations such as the limited tissue penetration of luminescence signals. At the same time, the beneficial features of luminescence imaging may be used to complement the routinely used radiologic- and nuclear medicine-based modalities. To fully exploit this integrated concept, and to relate the largely experimental luminesce-based guidance approaches into perspective with routine imaging approaches, it is essential to understand the advantages and limitations of this relatively new modality. By providing an overview of the available luminescence technologies and the various clinically evaluated exogenous luminescent tracers (fluorescent, hybrid, and theranostic tracers), this review attempts to place luminescence-based interventional molecular imaging technologies into perspective to the available radiologic- and/or nuclear medicine-based imaging technologies. At the same time, the transition from anatomic to physiologic and even molecular interventional luminescence imaging is illustrated.

Indocyanine Green: Historical Context, Current Applications, and Future Considerations

BACKGROUND

Indocyanine green (ICG) is a dye used in medicine since the mid-1950s for a variety of applications in in cardiology, ophthalmology, and neurosurgery; however, its fluorescent properties have only recently been used in the intraoperative evaluation of tissue perfusion.

METHOD

A literature review was conducted on the characterization and employment of ICG within the medical field. Historical and current context of ICG was examined while also considering implications for its future use.

RESULTS

ICG is a relatively nontoxic, unstable compound bound by albumin in the intravascular space until rapid clearance by the liver. It has widespread uses in hepatic, cardiac, and ophthalmologic studies, and its use in analyzing tissue perfusion and identifying sentinel lymph nodes in cancer staging is gaining popularity.

CONCLUSIONS

ICG has myriad applications and poses low risk to the patient. Its historical uses have contributed to medical knowledge, and it is now undergoing investigation for quantifying tissue perfusion, providing targeted therapies, and intraoperative identification of neurovascular anatomy, ophthalmic structures, and sentinel lymph nodes. New applications of ICG may lead to reduction in postoperative wound-related complications, more effective ophthalmologic procedures, and better detection and treatment of cancer cells.

ICG Fluorescence Technique for the Detection of Sentinel Lymph Nodes in Breast Cancer: Results of a Prospective Open-label Clinical Trial

Introduction: Detection of sentinel lymph nodes (SLN) is the standard procedure to evaluate axillary lymph node status in breast cancer. In addition to known and established procedures such as the blue dye method and scintigraphy, this study investigated the efficacy of a method based on use of the fluorescent dye indocyanine green (ICG). Patients and Method: A total of 126 women with breast cancer histologically verified by punch biopsy were studied during surgical removal of SLN. In addition to SLN marking with technetium and scintigraphy, intra-individual comparison was done using indocyanine green (ICG) for marking instead of the standard blue dye. Results: Scintigraphy had a detection rate of 96 %; the detection rate with ICG was just under 89 %. A body mass index (BMI) > 40 was found to be a limiting factor for the fluorescent method. Investigation into potential toxicities associated with the use of the fluorescent dye ICG revealed no systemic or even local side effects. The fluorescent method was found to be significantly less expensive than the scintigraphy method. Conclusion: The ICG fluorescence technique for the detection of SLN was found to be a valid and feasible method in clinical practice when compared directly with the blue dye method and scintigraphy.

Sentinel Lymph Node Detection Using Carbon Nanoparticles in Patients with Early Breast Cancer

PURPOSE

Carbon nanoparticles have a strong affinity for the lymphatic system. The purpose of this study was to evaluate the feasibility of sentinel lymph node biopsy using carbon nanoparticles in early breast cancer and to optimize the application procedure.

METHODS

Firstly, we performed a pilot study to demonstrate the optimized condition using carbon nanoparticles for sentinel lymph nodes (SLNs) detection by investigating 36 clinically node negative breast cancer patients. In subsequent prospective study, 83 patients with clinically node negative breast cancer were included to evaluate SLNs using carbon nanoparticles. Another 83 SLNs were detected by using blue dye. SLNs detection parameters were compared between the methods. All patients irrespective of the SLNs status underwent axillary lymph node dissection for verification of axillary node status after the SLN biopsy.

RESULTS

In pilot study, a 1 ml carbon nanoparticles suspension used 10-15min before surgery was associated with the best detection rate. In subsequent prospective study, with carbon nanoparticles, the identification rate, accuracy, false negative rate was 100%, 96.4%, 11.1%, respectively. The identification rate and accuracy were 88% and 95.5% with 15.8% of false negative rate using blue dye technique. The use of carbon nanoparticles suspension showed significantly superior results in identification rate (p = 0.001) and reduced false-negative results compared with blue dye technique.

CONCLUSION

Our study demonstrated feasibility and accuracy of using carbon nanoparticles for SLNs mapping in breast cancer patients. Carbon nanoparticles are useful in SLNs detection in institutions without access to radioisotope.

Sentinel lymph node biopsy under fluorescent indocyanin green guidance: Initial experience

OBJECTIVE

Sentinel lymph node biopsy can be applied by using either blue dye or radionuclide method or both in breast cancer. Fluorescent imaging with indocyanine green is a new defined method. This study evaluates the applicability of sentinel lymph node biopsy via fluorescent indocyanine green.

MATERIAL AND METHODS

IC-VIEW (Pulsion Medical Systems AG, Munich, Germany) infrared visualization system was used for imaging. Two mL of indocyanine green was injected to visualize sentinel lymph nodes. After injection, subcutaneous lymphatics were traced and sentinel lymph nodes were found with simultaneous imaging. Sentinel lymph nodes were excised under fluorescent light guidance, and excised lymph nodes were examined histopathologically. Patients with sentinel lymph node metastases underwent axillary dissection.

RESULTS

Four patients with sentinel lymph node biopsy due to breast cancer were included in the study. Sentinel lymph nodes were visualized with indocyanine green in all patients. The median number of excised sentinel lymph node was 2 (2-3). Two patients with lymph node metastasis underwent axillary dissection. No metastasis was detected in lymph nodes other than the sentinel nodes in patients with axillary dissection. There was no complication during and after the operation related to the method.

CONCLUSION

According to our limited experience, sentinel lymph node biopsy under fluorescent indocyanine green guidance, which has an advantage of simultaneous visualization, is technically feasible.

Clostridium perfringens enterotoxin C-terminal domain labeled to fluorescent dyes for in vivo visualization of micrometastatic chemotherapy-resistant ovarian cancer

Identification of micrometastatic disease at the time of surgery remains extremely challenging in ovarian cancer patients. We used fluorescence microscopy, an in vivo imaging system and a fluorescence stereo microscope to evaluate fluorescence distribution in Claudin-3- and -4-overexpressing ovarian tumors, floating tumor clumps isolated from ascites and healthy organs. To do so, mice harboring chemotherapy-naïve and chemotherapy-resistant human ovarian cancer xenografts or patient-derived xenografts (PDXs) were treated with the carboxyl-terminal binding domain of the Clostridium perfringens enterotoxin (c-CPE) conjugated to FITC (FITC-c-CPE) or the near-infrared (NIR) fluorescent tag IRDye CW800 (CW800-c-CPE) either intraperitoneally (IP) or intravenously (IV). We found tumor fluorescence to plateau at 30 min after IP injection of both the FITC-c-CPE and the CW800-c-CPE peptides and to be significantly higher than in healthy organs (p < 0.01). After IV injection of CW800-c-CPE, tumor fluorescence plateaued at 6 hr while the most favorable tumor-to-background fluorescence ratio (TBR) was found at 48 hr in both mouse models. Importantly, fluorescent c-CPE was highly sensitive for the in vivo visualization of peritoneal micrometastatic tumor implants and the identification of ovarian tumor spheroids floating in malignant ascites that were otherwise not detectable by conventional visual observation. The use of the fluorescent c-CPE peptide may represent a novel and effective optical approach at the time of primary debulking surgery for the real-time detection of micrometastatic ovarian disease overexpressing the Claudin-3 and -4 receptors or the identification of residual disease at the time of interval debulking surgery after neoadjuvant chemotherapy treatment.

Evaluation of the Clinical Utility of the ICG Fluorescence Method Compared with the Radioisotope Method for Sentinel Lymph Node Biopsy in Breast Cancer

PURPOSE

This study compared the clinical utility of indocyanine green (ICG) fluorescence and radioisotope (RI) for sentinel lymph node (SLN) detection in breast cancer.

METHODS

Women with node-negative breast cancer underwent SLN biopsy using ICG fluorescence and RI. The primary end point was the sensitivity of ICG fluorescence compared with RI in the patients with tumor-positive SLNs. Secondary end points included detection rates for SLN, the additive effect of ICG fluorescence to RI, signature of positive SLNs according to tier, and adverse events related to ICG administration.

RESULTS

A total of 847 women with clinical node-negative breast cancer underwent SLN biopsy, and 821 patients were included in the per-protocol analysis. SLN mapping was performed using ICG fluorescence and RI. The overall detection of SLNs using ICG fluorescence was identical to RI (97.2 vs. 97.0 %, P = 0.88), and the combination of both methods achieved a significant improvement compared with RI alone (99.8 vs. 97.0 %, P < 0.001). The detection rate for tumor-positive SLN was 93.3 % for ICG fluorescence and 90.0 % for RI, and the sensitivity of the ICG fluorescence method was 95.7 % (95 % CI 91.3-98.3, P = 0.11). The additional use of ICG significantly improved positive SLN detection for RI (97.2 vs. 90.0 %, P < 0.001). There were no serious adverse events related to hypersensitivity to ICG.

CONCLUSIONS

The ICG fluorescence method may be an acceptable alternative to SLN detection using RI in breast cancer.

On the horizon: Optical imaging for cutaneous squamous cell carcinoma

BACKGROUND

Surgical resection with negative margins remains the standard of care for high-risk cutaneous squamous cell carcinoma (SCC). However, surgical management is often limited by poor intraoperative tumor visualization and inability to detect occult nodal metastasis. The inability to intraoperatively detect microscopic disease can lead to additional surgery, tumor recurrence, and decreased survival.

METHODS

A comprehensive literature review was conducted to identify studies incorporating optical imaging technology in the management of cutaneous SCC (January 1, 2000-December 1, 2014).

RESULTS

Several innovative optical imaging techniques, Raman spectroscopy, confocal microscopy, and fluorescence imaging, have been developed for intraoperative surgical guidance. Fifty-seven studies review the ability of these techniques to improve cutaneous SCC localization at the gross and microscopic level.

CONCLUSION

Significant advances have been achieved with real-time optical imaging strategies for intraoperative cutaneous SCC margin assessment and tumor detection. Optical imaging holds promise in improving the percentage of negative surgical margins and in the early detection of micrometastatic disease. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2204-E2213, 2016.

Anatomical laparoscopic hepatectomy for hepatocellular carcinoma using indocyanine green fluorescence imaging

PURPOSE

It is important to minimize surgical invasiveness in the therapy of patients with hepatocellular carcinoma (HCC), and consequently laparoscopic hepatic resection is widely performed. However, most anatomical resections, except left lateral sectionectomy, remain difficult technically, and laparoscopy-assisted procedures have been introduced as an alternative approach because of the safety and curative success of the operation. We reported previously pure laparoscopic subsegmentectomy of the liver using puncture of the portal branch under percutaneous ultrasound (US) with artificial ascites. Herein, we describe pure anatomical laparoscopic segmentectomy using the puncture method with indocyanine green (ICG) injection under laparoscopic US.

PATIENTS AND METHODS

Pure laparoscopic segmentectomy was planned for 2 patients with HCC of the liver. Identification of the segment was performed by ICG injection for optical imaging using near-infrared fluorescence under laparoscopic US guidance.

RESULTS

The procedures were completed successfully, and the postoperative courses were uneventful.

CONCLUSIONS

Pure laparoscopic segmentectomy for HCC with a conventional puncture technique by ICG injection under laparoscopic US is considered to be a useful procedure featuring both low invasiveness and curative success.

Availability of tissue rinse liquid-based cytology for the rapid diagnosis of sentinel lymph node metastasis and improved bilateral detection by photodynamic eye camera

OBJECTIVE

On sentinel lymph node navigation surgery for early invasive cervical cancers, to gain high sensitivity and specificity, the sentinel nodes should be detected bilaterally and pathological diagnosis should be sensitive to detect micrometastasis. To improve these problems, we tried tissue rinse liquid-based cytology and the photodynamic eye.

METHODS

From 2005 to 2013, 102 patients with Stage Ib1 uterine cervical cancer were subjected to sentinel lymph node navigation surgery with Technetium-99 m colloid and blue dye. For the recent 11 patients with whom bilateral sentinel node detection was not available, the photodynamic eye was selectively examined. The detected sentinel node was cut along the minor axis into 2 mm slices, soaked in 10 ml CytoRich red and then subjected to tissue rinse liquid-based cytology at the time of surgery.

RESULTS

With the accumulation of 102 Ib1 patients subjected to sentinel lymph node navigation surgery, the bilateral sentinel node detection rate was 67.7%. The photodynamic eye was examined for the recent 11 patients who did not have bilateral signals. Out of the 11, 10 patients obtained bilateral signals successfully. During the period of examining the photodynamic eye, a total of 34 patients were subjected to sentinel lymph node navigation surgery. Thus, the overall bilateral detection rate increased to 97% in this subset. Two hundred and five lymph nodes were available as sentinel nodes. The sensitivity of tissue rinse liquid-based cytology was 91.7%, and the specificity was 100%. False positivity was 0% and false negativity was 8.3%. Detection failure was observed only with one micrometastasis and one case of isolated tumor cells.

CONCLUSION

Combination of photodynamic eye detection and tissue rinse liquid-based cytology pathology can be a promising method for more rewarding sentinel node detection.

Macro- and microscopic findings of ICG fluorescence in liver tumors

Background

Reports detailing microscopic observations of indocyanine green (ICG) fluorescence imaging (IFI) in hepatocellular carcinoma (HCC) and metastatic liver cancer are rare. We were able to perform macro- and microscopic IFI results in postoperative paraffin-embedded tissue samples and formalin-fixed specimens from liver tumors.

Methods

Between April 2010 and March 2014, 19 patients with HCC or liver metastases of colorectal tumors underwent liver resection. ICG solution was injected into the peripheral vein from 14 to 2 days prior to operation. We observed liver tumor IFI during the laparotomy and IFI in resected liver sections using a photo dynamic emission (PDE) camera. The IFI of paraffin-embedded tissue samples was observed using a charge-coupled device (CCD) camera. Moreover, we microscopically performed tissue section IFI using a fluorescence microscope with an ICG-B-NQF.

Results

We performed that IFI characteristics depended on tumor type macroscopically and microscopically. In normal liver tissue, fluorescence consistent with the bile canaliculus was observed. HCC had heterogeneous IFI, forming a total or partial tumor and rim pattern. In metastatic carcinoma, we performed that non-tumor cells in the marginal region showed fluorescence and tumor cells in the central region did not fluoresce.

Conclusions

We confirmed that the variations of ICG fluorescence imaging patterns reflect different tumor characteristics in not only macroscopic imaging as previous reports but also microscopic imaging. Moreover, the ICG fluorescence method is useful for postoperative pathological detection of microscopic lesions in histopathological specimens. ICG fluorescence in paraffin-embedded tissue samples and formalin-fixed specimens is preserved in the long term.

Clinical application of indocyanine green (ICG) fluorescent imaging of hepatoblastoma

BACKGROUND/PURPOSE

Although the usefulness of intraoperative indocyanine green (ICG) fluorescent imaging for the resection of hepatocellular carcinoma has been reported, its usefulness for the resection of hepatoblastoma remains unclear. This study clarifies the feasibility of intraoperative ICG fluorescent imaging for the resection of hepatoblastoma.

METHODS

In three hepatoblastoma patients, a primary tumor, recurrent tumor, and lung metastatic lesions were intraoperatively examined using a near-infrared fluorescence imaging system after the preoperative administration of ICG.

RESULTS

ICG fluorescent imaging was useful for the surgical navigation in hepatoblastoma patients. In the first case, the primary hepatoblastoma exhibited intense fluorescence during right hepatectomy, but no fluorescence was detected in the residual liver. In the second case, a recurrent tumor exhibited fluorescence between the residual liver and diaphragm. A complete resection of the residual liver, with a partial resection of the diaphragm, followed by liver transplantation was performed. In the third case with multiple lung metastases, each metastatic lesion showed positive fluorescence, and all were completely resected. These fluorescence-positive lesions were pathologically proven to be viable hepatoblastoma cells.

CONCLUSION

Intraoperative ICG fluorescence imaging for patients with hepatoblastoma was feasible and useful for identifying small viable lesions and confirming that no remnant tumor remained after resection.