High rate of solitary sentinel node metastases identification by fluorescence-guided lymphatic imaging in breast cancer

Indocyanine Green Fluorescence-Guided Sentinel Node Biopsy in Breast Cancer Within a North African Population: A Retrospective Study

Objective

Radio isotopes and blue dyes alone or in combination are the most commonly used tracer agents in sentinel node (SN) biopsy for early breast cancer. Recent studies have found fluorescence method using indocyanine green (ICG) as a promising technology with fewer disadvantages.

Materials and Methods

Retrospective analysis of our database that included patients with clinically node-negative breast cancer scheduled for breast surgery and SN biopsy between 2016 and January 2021. Patients who underwent detection using fluorescence-ICG were included in this study.

Results

A total of 47 patients were included. Median age was 50 (range: 24-78) years. Mean tumor size was 3.4 ± 1.5 cm. All patients received ICG injection and 11 received a combination of ICG and blue dye. Forty-five successful SN identifications with ICG were performed and 99 nodes retrieved. Eleven procedures were undertaken after initial systemic therapy. Twenty-four patients had at least one positive SN for malignancy. Mean follow up was 29.2 months and no axillary recurrence was noted during the study period.

Conclusion

ICG appears to be a feasible and accurate method for SN biopsy with high identification rate. This is the first study of ICG in sentinel node biopsy in a North African population.

Performance of Indocyanine-Green Imaging for Sentinel Lymph Node Mapping and Lymph Node Metastasis in Esophageal Cancer: Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Lymphatic mapping with indocyanine-green (ICG) and near-infrared light fluorescent imaging is widely used for sentinel lymph node staging in different types of cancer but is not fully accepted for all procedures because studies have reported heterogeneous results. This study aimed to assess the detection rate (DR) of ICG imaging for sentinel lymph node mapping (SLNM) and lymph node metastases (LNMs) in esophageal cancer.

METHODS

A systematic search was performed to identify relevant studies examining the use of ICG imaging for SLNM in patients with esophageal cancer. Extracted results were pooled in a single-proportion meta-analysis, with a random-effects model, presented as forest plots.

RESULTS

Six studies were included in the analysis. The ICG DR for SLNM was 89% [95% confidence interval (CI) 71%-96%]. The pooled sensitivity and specificity values for the detection of LNMs were 84% (95% CI 64%-94%) and 15% (95% CI 3%-45%), respectively. A trend towards a lower DR was found with increasing mean latency time between ICG injection and SLNM.

CONCLUSIONS

ICG imaging is a technique that potentially could improve lymph node yield excision and, as a consequence, improve the detection of lymph node metastases.

Evidence of stage progression in a novel, validated fluorescence-navigated and microsurgical-assisted secondary lymphedema rodent model

Secondary lymphedema (SL)is a frequent and devastating complication of modern oncological therapy and filarial infections. A lack of a reliable preclinical model to investigate the underlying mechanism of clinical stage progression has limited the development of new therapeutic strategies. Current first line treatment has shown to be merely symptomatic and relies on lifetime use of compression garments and decongestive physiotherapy. In this study, we present the development of a secondary lymphedema model in 35 rats using pre- and intraoperative fluorescence-guided mapping of the lymphatics and microsurgical induction. In contrast to the few models reported so far, we decided to avoid the use of radiation for lymphedema induction. It turned out, that the model is nearly free of complications and capable of generating a statistically significant limb volume increase by water displacement measurements, sustained for at least 48 days. A translational, accurate lymphatic dysfunction was visualized by a novel VIS-NIR X-ray ICG-Clearance-Capacity imaging technology. For the first-time SL stage progression was validated by characteristic histological alterations, such as subdermal mast cell infiltration, adipose tissue deposition, and fibrosis by increased skin collagen content. Immunofluorescence confocal microscopy analysis suggested that stage progression is related to the presence of a characteristic α SMA+/HSP-47+/vimentin+ fibroblast subpopulation phenotype. These findings demonstrate that the in-vivo model is a reliable and clinically relevant SL model for the development of further secondary lymphedema therapeutic strategies and the analysis of the veiled molecular mechanisms of lymphatic dysfunction.

Detection of Sentinel Lymph Nodes with Near-Infrared Imaging in Malignancies

Optical molecular imaging, a highly sensitive and noninvasive technique which is simple to operate, inexpensive, and has the real-time capability, is increasingly being used in the diagnosis and treatment of carcinomas. The near-infrared fluorescence dye indocyanine green (ICG) is widely used in optical imaging for the dynamic detection of sentinel lymph nodes (SLNs) in real time improving the detection rate and accuracy. ICG has the advantages of low scattering in tissue absorbance, low auto-fluorescence, and high signal-to-background ratio. The detection rate of axillary sentinel lymph nodes biopsy (SLNB) in breast cancers with ICG was more than 95 %, the false-negative rate was lower than 10 %, and the average detected number ranged from 1.75 to 3.8. The combined use of ICG with nuclein or blue dye resulted in a lower false-negative rate. ICG is also being used for the sentinel node detection in other malignant cancers such as head and neck, gastrointestinal, and gynecological carcinomas. In this article, we provide an overview of numerous studies that used the near-infrared fluorescence imaging to detect the sentinel lymph nodes in breast carcinoma and other malignant cancers. It is expected that with improvements in the optical imaging systems together with the use of a combination of multiple dyes and verification in large clinical trials, optical molecular imaging will become an essential tool for SLN detection and image-guided precise resection.

Comparison of sentinel lymph node detection performances using blue dye in conjunction with indocyanine green or radioisotope in breast cancer patients: a prospective single-center randomized study

Objective:

This randomized study aimed to compare the clinical efficacy between the novel dual tracer composed of indocyanine green (ICG) and blue dye (BD) and the conventional dual tracer composed of radioisotope and BD for sentinel lymph node (SLN) mapping in patients with breast cancer.

Methods:

This study enrolled 471 clinically lymph node-negative patients with primary breast cancer. All patients underwent mastectomy, and those undergoing sentinel lymph node biopsy (SLNB) were randomized to receive blue dye plus radioisotope (RB group) or BD plus ICG (IB group). The detection performances on SLN identification rate, positive SLN counts, detection sensitivity, and false-negative rate were compared between the two groups.

Results:

In the IB group, 97% (194/200) of the patients who underwent the ICG and BD dual tracer injection showed fluorescent-positive lymphatic vessels within 2–5 min. The identification rate of SLNs was comparable between the IB group (99.0%, 198/200) and the RB group (99.6%, 270/271) (P = 0.79). No significant differences were observed in the identification rate of metastatic SLNs (22.5% vs. 22.9%, P > 0.05, RB group vs. IB group, the same below), positive SLN counts (3.72 ± 2.28 vs. 3.91 ± 2.13, P > 0.05), positive metastatic SLN counts (0.38 ± 0.84 vs. 0.34 ± 0.78, P > 0.05), SLNB detection sensitivity (94.4% vs. 92.5%, P > 0.05), or false-negative rate (5.6% vs. 7.5%, P > 0.05) between the two groups.

Conclusions:

ICG can be used as a promising alternative tracer for radioisotope in SLN mapping, and when it is combined with BD in lymphangiography, it offers comparable detection sensitivity compared to the conventional lymphatic mapping strategies that are widely used in clinical practice.

Feasibility of Real-Time Near-Infrared Fluorescence Tracer Imaging in Sentinel Node Biopsy for Oral Cavity Cancer Patients

Background

Sentinel node biopsy (SNB) is an established method in oral squamous cell carcinoma (OSCC) for staging the cN0 neck and to select patients who will benefit from a neck dissection. Near-infrared fluorescence (NIRF) imaging has the potential to improve the SNB procedure by facilitating intraoperative visual identification of the sentinel lymph node (SN). The purpose of this study was to evaluate the feasibility of fluorescence tracer imaging for SN detection in conjunction with conventional radio-guided technique.

Methods

Prospective study of patients with primary OSCC planned for tumor resection and SNB. Thirty patients were injected peritumorally with a bimodal tracer (ICG-^99mTc-Nanocoll) followed by lymphoscintigraphy and SPECT/CT to define the SNs and their anatomical location preoperatively. SNs were detected intraoperatively with a hand-held gamma-probe and a hand-held NIRF camera.

Results

In 29 of 30 subjects (97%), all preoperatively defined SNs could be identified intraoperatively using a combination of radioactive and fluorescence guidance. A total of 94 SNs (mean 3, range 1–5) that were both radioactive and fluorescent ex vivo were harvested. Eleven of 94 SNs (12%) could only be identified in vivo using NIRF imaging, and the majority of those were located in level 1 close to the primary tumor.

Conclusions

A combined fluorescent and radioactive tracer for SNB is feasible, and the additional use of NIRF imaging may improve the accuracy of SN identification in oral cancer patients. Intraoperative fluorescence guidance seems of particular value when SNs are located in close proximity to the injection site.

Diagnostic Performance of Indocyanine Green-Guided Sentinel Lymph Node Biopsy in Breast Cancer: A Meta-Analysis

Background

The diagnostic performance of indocyanine green (ICG) fluorescence-guided sentinel lymph node biopsy (SLNB) for the presence of metastases in breast cancer remains unclear.

Objective

We performed a meta-analysis to investigate the diagnostic performance of ICG-guided SLNB.

Methods

Eligible studies were identified from searches of the databases PubMed and EMBASE up to September 2015. Studies that reported the detection rate of ICG fluorescence-guided SLNB with full axillary lymph node dissection and histological or immunohistochemical examinations were included. A meta-analysis was performed to generate pooled detection rate, sensitivity, specificity, false negative rate, diagnostic odds ratio (DOR) and a summary receiver operator characteristic curve (SROC).

Results

Nineteen published studies were included to generate a pooled detection rate, comprising 2594 patients. The pooled detection rate was 0.98 (95% confidence interval [CI], 0.96–0.99). Six studies finally met the criteria for meta-analysis, which yielded a pooled sensitivity of 0.92 (95% CI, 0.85–0.96), specificity 1 (95% CI, 0.97–1), and DOR 311.47 (95% CI, 84.11–1153.39). The area under the SROC was 0.9758. No publication bias was found.

Conclusion

ICG fluorescence-guided SLNB is viable for detection of lymph node metastases in breast cancer. Large-scale randomized multi-center trials are necessary to confirm our results.

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.

[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.

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.

Optimising magnetic sentinel lymph node biopsy in an in vivo porcine model

The magnetic technique for sentinel lymph node biopsy (SLNB) has been evaluated in several clinical trials. An in vivo porcine model was developed to optimise the magnetic technique by evaluating the effect of differing volume, concentration and time of injection of magnetic tracer. A total of 60 sentinel node procedures were undertaken. There was a significant correlation between magnetometer counts and iron content of excised sentinel lymph nodes (SLNs) (r=0.82; P<0.001). Total number of SLNs increased with increasing volumes of magnetic tracer (P<0.001). Transcutaneous magnetometer counts increased with increasing time from injection of magnetic tracer (P<0.0001), plateauing within 60min. Increasing concentration resulted in higher iron content of SLNs (P=0.006). Increasing magnetic tracer volume and injecting prior to surgery improve transcutaneous 'hotspot' identification but very high volumes, increase the number of nodes excised.

FROM THE CLINICAL EDITOR

Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging of breast cancer patients. Although the current gold standard technique is the combined injection of technetium-labelled nanocolloid and blue dye into the breast, the magnetic technique, using superparamagnetic carboxydextran-coated iron oxide (SPIO), has also been demonstrated as a feasible alternative. In this article, the authors set up to study factors in order to optimize the magnetic tracers.

Current status of optical imaging for evaluating lymph nodes and lymphatic system

Optical imaging techniques use visual and near infrared rays. Despite their considerably poor penetration depth, they are widely used due to their safe and intuitive properties and potential for intraoperative usage. Optical imaging techniques have been actively investigated for clinical imaging of lymph nodes and lymphatic system. This article summarizes a variety of optical tracers and techniques used for lymph node and lymphatic imaging, and reviews their clinical applications. Emerging new optical imaging techniques and their potential are also described.

Novel techniques for sentinel lymph node biopsy in breast cancer: a systematic review

The existing standard for axillary lymph node staging in breast cancer patients with a clinically and radiologically normal axilla is sentinel lymph node biopsy with a radioisotope and blue dye (dual technique). The dependence on radioisotopes means that uptake of the procedure is limited to only about 60% of eligible patients in developed countries and is negligible elsewhere. We did a systematic review to assess three techniques for sentinel lymph node biopsy that are not radioisotope dependent or that refine the existing method: indocyanine green fluorescence, contrast-enhanced ultrasound using microbubbles, and superparamagnetic iron oxide nanoparticles. Our systematic review suggested that these new methods for sentinel lymph node biopsy have clinical potential but give high levels of false-negative results. We could not identify any technique that challenged the existing standard procedure. Further assessment of these techniques against the standard dual technique in randomised trials is needed.

Indocyanine green fluorescence-guided sentinel node biopsy: a meta-analysis on detection rate and diagnostic performance

BACKGROUND

Indocyanine green (ICG) fluorescence-guided sentinel node biopsy (SLNB) has been successfully employed in various kinds of tumors. Clinical results of previous studies on this technique are at different levels of evidence. This Meta-analysis was conducted to provide a more precise estimation on its clinical performance.

METHODS

Eligible studies were identified from systematical PubMed and EMBASE searches; data were extracted. A Meta-analysis was performed to generate pooled detection rate, sensitivity, specificity, diagnostic odds ratio (DOR) and summary receiver operator characteristic curves.

RESULTS

Fifteen published articles were included. Clinical data of 513 patients were obtained. The pooled detection rate, the pooled sensitivity, the pooled specificity, the pooled DOR and their 95% confidence intervals (95% CI) were 0.96 (0.91-0.99), 0.87 (0.79-0.92), 1.00 (0.99-1.00) and 150.13 (57.42-392.56), respectively. Significant heterogeneities existed among studies. Significant publication bias was found in detection rate. The concentration < 5 mg/ml subgroup and the injected volume ≥2 ml subgroup had higher DORs, sensitivities and detection rates than the concentration ≥ 5 mg/ml subgroup and the injected volume <2 ml subgroup, respectively.

CONCLUSION

Based on this Meta-analysis, this technique could be valued promising for detecting the presence of LN metastases. ICG injection with reduced concentration and larger volume may provide improved performance.

Fluorescence-guided surgery with a fluorophore-conjugated antibody to carcinoembryonic antigen (CEA), that highlights the tumor, improves surgical resection and increases survival in orthotopic mouse models of human pancreatic cancer

BACKGROUND

We have developed a method of distinguishing normal tissue from pancreatic cancer in vivo using fluorophore-conjugated antibody to carcinoembryonic antigen (CEA). The objective of this study was to evaluate whether fluorescence-guided surgery (FGS) with a fluorophore-conjugated antibody to CEA, to highlight the tumor, can improve surgical resection and increase disease-free survival (DFS) and overall survival (OS) in orthotopic mouse models of human pancreatic cancer.

METHODS

We established nude-mouse models of human pancreatic cancer with surgical orthotopic implantation of the human BxPC-3 pancreatic cancer. Orthotopic tumors were allowed to develop for 2 weeks. Mice then underwent bright-light surgery (BLS) or FGS 24 h after intravenous injection of anti-CEA-Alexa Fluor 488. Completeness of resection was assessed from postoperative imaging. Mice were followed postoperatively until premorbid to determine DFS and OS.

RESULTS

Complete resection was achieved in 92 % of mice in the FGS group compared to 45.5 % in the BLS group (p = 0.001). FGS resulted in a smaller postoperative tumor burden (p = 0.01). Cure rates with FGS compared to BLS improved from 4.5 to 40 %, respectively (p = 0.01), and 1-year postoperative survival rates increased from 0 % with BLS to 28 % with FGS (p = 0.01). Median DFS increased from 5 weeks with BLS to 11 weeks with FGS (p = 0.0003). Median OS increased from 13.5 weeks with BLS to 22 weeks with FGS (p = 0.001).

CONCLUSIONS

FGS resulted in greater cure rates and longer DFS and OS using a fluorophore-conjugated anti-CEA antibody. FGS has potential to improve the surgical treatment of pancreatic cancer.

One-year postoperative morbidity associated with near-infrared-guided indocyanine green (ICG) or ICG in conjugation with human serum albumin (ICG:HSA) sentinel lymph node biopsy

BACKGROUND

Sentinel lymph node biopsy (SLNB) is a standard staging procedure in breast cancer and skin melanoma patients. Radioactive colloid (RC) and blue dye are the routinely used markers for staining. The new dye used in this procedure, indocyanine green (ICG), seems to have true potential in near-infrared-guided SLNB. The aim of this study was to analyze 1-year morbidity after SLNB using RC and ICG or RC and ICG conjugated to human serum albumin (ICG:HSA) in breast cancer and skin melanoma patients.

METHODS

Forty-nine patients diagnosed with breast cancer and 10 patients with skin melanoma underwent SLNB using ICG with RC and ICG:HSA with RC. A total of 47 SLNB patients without the need for additional lymphadenectomy were evaluated approximately 1 year (11-13 months) for the presence of tattoo, extremity swelling, nerve dysfunction/pain, range of motion, and stiffness.

RESULTS

From the 47 patients examined, long-term morbidity was present in 3 (6.4%). In 1 patient, tattoo persisted for 11 months. Mild lymphedema was seen in 1 patient, and 1 patient exhibited minor functional deficit.

CONCLUSIONS

Using ICG or ICG:HSA seems to be safe, and long-term morbidity in SLNB patients is low. However, skin discoloration may appear as it does after the use of blue dye, and an increased number of harvested nodes might be associated with an increased number of iatrogenic lymphedema.

Clinical trial of combined radio- and fluorescence-guided sentinel lymph node biopsy in breast cancer

BACKGROUND

Combining radioactive colloids and a near-infrared (NIR) fluorophore permits preoperative planning and intraoperative localization of deeply located sentinel lymph nodes (SLNs) with direct optical guidance by a single lymphatic tracer. The aim of this clinical trial was to evaluate and optimize a hybrid NIR fluorescence and radioactive tracer for SLN detection in patients with breast cancer.

METHODS

Patients with breast cancer undergoing SLN biopsy were enrolled. The day before surgery, a periareolar injection of indocyanine green (ICG)-99mTc-radiolabelled nanocolloid was administered and a lymphoscintigram acquired. Blue dye was injected immediately before surgery. Intraoperative SLN localization was performed using a γ probe and the Mini-FLARE™ NIR fluorescence imaging system. Patients were divided into two dose groups, with one group receiving twice the particle density of ICG and nanocolloid, but the same dose of radioactive 99mTc.

RESULTS

Thirty-two patients were enrolled in the trial. At least one SLN was identified before and during operation. All 48 axillary SLNs could be detected by γ tracing and NIR fluorescence imaging, but only 42 of them stained blue. NIR fluorescence imaging permitted detection of lymphatic vessels draining to the SLN up to 29 h after injection. Doubling the particle density did not yield a difference in fluorescence intensity (median 255 (range 98-542) versus 284 (90-921) arbitrary units; P = 0.590) or signal-to-background ratio (median 5·4 (range 3·0-15·4) versus 4·9 (3·5-16·3); P = 1·000) of the SLN.

CONCLUSION

The hybrid NIR fluorescence and radioactive tracer permitted accurate preoperative and intraoperative detection of the SLNs in patients with breast cancer.

REGISTRATION NUMBER

NTR3685 (Netherlands Trial Register; http://www.trialregister.nl).

An experimental study to evaluate the Fluobeam 800 imaging system for fluorescence-guided lymphatic imaging and sentinel node biopsy

BACKGROUND

Visualization of the lymphatic system is challenging. Lymphatic imaging is a crucial diagnostic tool for benign and malignant lymphatic pathologies. Fluorescence-guided imaging allows selective lymphatic mapping and sentinel lymph node (SLN) identification. There are a few fluorescence systems, but some drawbacks remain due to technical and ergonomic aspects. The aim of this study was to evaluate the feasibility of the new Fluobeam 800 imaging system.

METHODS

After approval by the ethics committee, the system was evaluated for lymphography and SLN biopsy in an animal model. Five pigs each with 4 lymph node (LN) stations (n = 20 LN stations) were subjected to lymphatic imaging using indocyanine green (ICG). Additionally, the use of ICG was compared with ICG adsorbed to human serum albumin (ICG-HSA). Lymphatic vessels and SLN identification rates were measured.

RESULTS

After injection, a clear fluorescence signal of the lymphatic vessels was visualized leading to the LN station. Overall, ICG fluorescence imaging identified a mean of 2.0 lymphatic vessels and 1.1 (range = 1-2) SLN in 20 of 20 LN stations. Reverse lymphography was feasible. A clinical difference in resolution was not detected between use of ICG-HSA and ICG.

CONCLUSION

This is the first study analyzing the feasibility of the Fluobeam 800 imaging system allowing transcutaneous real-time imaging. It enables detection of the SLN by fluorescence retention with increased detection depth and resolution. After fixation to the ceiling, the ergonomics advanced for simultaneous field navigation and dissection. The new system can be applied for lymphatic imaging for lympatico-reconstructive surgery and SLN biopsy.

Sentinel lymph nodes fluorescence detection and imaging using Patent Blue V bound to human serum albumin

Patent Blue V (PBV), a dye used clinically for sentinel lymph node detection, was mixed with human serum albumin (HSA). After binding to HSA, the fluorescence quantum yield increased from 5 × 10(-4) to 1.7 × 10(-2), which was enough to allow fluorescence detection and imaging of its distribution. A detection threshold, evaluated in scattering test objects, lower than 2.5 nmol × L(-1) was obtained, using a single-probe setup with a 5-mW incident light power. The detection sensitivity using a fluorescence imaging device was in the µmol × L(-1) range, with a noncooled CCD camera. Preclinical evaluation was performed on a rat model and permitted to observe inflamed nodes on all animals.