A novel method for sentinel lymph node biopsy by indocyanine green fluorescence technique in breast cancer

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

[Fluorescence lymphography for sentinal lymph node biopsy in breast cancer]

OBJECTIVE

To study diagnostic value of fluorescence lymphography for sentinel lymph node biopsy in breast cancer.

MATERIAL AND METHODS

The study enrolled 25 patients with breast cancer T1-2N0-1M0 between March 2023 and July 2023. Eight ones underwent neoadjuvant chemotherapy. In 3 patients, morphologically verified metastases cN1 in axillary lymph nodes regressed after treatment. After sentinel lymph node biopsy, all patients underwent standard axillary lymphadenectomy. Subareolar injection of indocyanine green 1 ml (5 mg/ml) was performed immediately before surgery. Fluorescence imaging was performed using the MARS system.

RESULTS

Detection rate was 100%. Mean number of sentinel lymph nodes was 2. Metastatic lesions of sentinel lymph nodes were observed in 6 patients (24%) with micro-metastases in 2 cases. In 50% of cases, metastatic lesion did not extend beyond sentinel lymph nodes. False negative result was obtained in 1 (4%) patient. Mean number of metastases was 1.8 (max 3 in one patient).

CONCLUSION

Sentinel lymph node biopsy with fluorescence lymphography is a sensitive method. The advantages of this technique are visualization of subcutaneous lymphatic vessels and skin incision for access to sentinel lymph nodes, as well as visualization of sentinel lymph nodes after skin incision.

Comparison of indirect computed tomographic lymphography and near-infrared fluorescence sentinel lymph node mapping for integumentary canine mast cell tumors

OBJECTIVE

To compare the independent and combined use of indirect computed tomographic lymphography (ICTL) and near-infrared fluorescence (NIRF) for sentinel lymph node (SLN) mapping in dogs with integumentary mast cell tumors (MCT) and report the metastatic LN rate.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Twenty client-owned dogs.

METHODS

Dogs underwent preoperative ICTL, then intraoperative NIRF SLN mapping and excision of the anatomic lymph node (ALN) and/or SLN, and primary MCT. Technique agreement was complete if the same SLN was detected, and partial if the same SLN was detected along with additional SLN. No agreement occurred if the techniques detected different or no SLN. MCT were graded using two- and three-tier schemes, and LN were graded from HN0-3; HN2-3 were considered metastatic.

RESULTS

Complete, partial, and no agreement between ICTL and NIRF was seen in 8/20 (40%), 8/20 (40%), and 4/20 (20%) dogs, respectively. Detection of ICTL-SLN and NIRF-SLN failed in 1/20 (5%) and 4/20 (20%), respectively. Tumors were grade II/low-grade in 19/20 (95%) and grade III/high-grade in 1/20 (5%) dogs. Nineteen out of 20 (95%) dogs had HN2-3 LN.

CONCLUSIONS

Technique agreement of at least one SLN was seen in 16/20 (80%) dogs. Although most MCT were classified as intermediate to low grade, LN metastases were commonly detected.

CLINICAL SIGNIFICANCE

Combining ICTL and NIRF for MCT SLN mapping yields high SLN detection rates. Lymph node metastasis may be more common than previously reported for intermediate to low grade MCT.

Indo-cyanine green administration to identify loss of lymph after axillary lymph node dissection

Background

Near infrared fluorescence imaging with Indocyanine Green (ICG) is now used for the imaging of lymph nodes and lymphatic vessels. In this work, we investigated the impact of its pre-operative and peri-operative administration on our ability to detect axillary lymphatic loss after breast cancer surgery.

Methods

One subcutaneous injection of ICG was administered in the ipsilateral hand of 109 women who were scheduled to have either a mastectomy with total axillary lymph node dissection (CALND) or a lumpectomy with selective lymphadenectomy (SLN) the day before (n = 53) or the same day of surgery (n = 56). The lymph leakages were assessed by means of the application of a compress in the operated armpit and by the presence or absence of fluorescence on it, as well as in the post-operative axillary drains.

Results

The compress was fluorescent in 28% of SLN patients and 71% of CALND patients. The liquids in the axillary drains were also fluorescent in 71% of patients with CALND. No statistical significance was observed between the ICG injection groups. The association between compressive fluorescent and the presence of fluorescence in the axillary drains is significant in the pre-operative subgroup and in the whole group.

Conclusion

Our research demonstrates that lymphatic leaks aid in the development of seromas and calls into question the effectiveness of the ligatures and/or cauterizations used during surgery. A prospective, multicentric, randomized trial should be conducted to verify the efficacy of this approach.

The primary application of indocyanine green fluorescence imaging in surgical oncology

Background

Indocyanine green (ICG) is a nontoxic, albumin-bound, liver-metabolized fluorescent iodide dye that has been widely utilized in clinical applications since the mid-1950s. However, after the 1970s, in-depth research on the fluorescence properties of ICG greatly expanded its application in the medical field.

Methods

In our mini-review, we searched the relevant literature on common oncology surgeries from PubMed, including lung cancer, breast cancer, gastric cancer, colorectal cancer, liver cancer, and pituitary tumors, using keywords such as indocyanine green, fluorescence imaging technology, and near-infrared fluorescence imaging. In addition, the application of targeted ICG photothermal technology in tumor therapy is briefly mentioned.

Results

In this mini-review, we analyzed studies on ICG fluorescence imaging in common surgical oncology and offered a thorough analysis of each form of cancer or tumor.

Conclusion

ICG has demonstrated significant potential in the detection and treatment of tumors in current clinical practice, although many applications are still in the preliminary stages, and multicenter studies are still required to more precisely define its indications, effectiveness, and safety.

ICG-ER: a new probe for photoimaging and photothermal therapy for breast cancer

Breast cancer is common cancer type with high mortality. There are still inperfections in the traditional diagnosis and treatment methods for cancer. Photoacoustic imaging combines the advantages of high specificity and deep tissue penetration and is especially suitable for early cancer detection and treatment monitoring. With its specificity and noninvasiveness; photothermal therapy has become one of the best representative treatment methods. Indocyanine green (ICG) is a near-infrared imaging reagent approved by the FDA for clinical application, with a potential application for photothermal therapy. ICG has low targeting specificity. Through the combination of EB and ICG, the timeliness of ICG circulation in vivo is improved, and the tumor targeting of ICG-E is improved by using RGD. ICG-ER, an integrated optical probe for diagnosis and treatment, was constructed, and high uptake of ICG-ER by 4T1 cells was observed by flow cytometry and confocal laser scanning microscopy (CLSM). ICG-ER photoacoustic signal intensity is concentration-dependent. In vivo photoacoustic imaging showed that the ICG-ER concentration time in the tumor site was long and reached a peak at 42 hours. Under laser irradiation, the temperature of the tumor site in mice that were injected with ICG-ER reached 56°C. After photothermal treatment, the tumor tissue in the mice showed obvious necrosis and no tumor recurrence, proving that ICG-ER has a good photothermal effect. Based on the above results, ICG-ER can be used in breast cancer optical imaging and photothermal therapy, which is expected to provide new ideas for breast cancer clinical diagnosis and treatment.

A Prospective Self-Controlled Study of Indocyanine Green, Radioisotope, and Methylene Blue for Combined Imaging of Axillary Sentinel Lymph Nodes in Breast Cancer

Purpose

This self-controlled study aimed to clarify whether indocyanine green (ICG) could be an alternative tracer in the absence of radioisotope (RI) for combined imaging of axillary sentinel lymph node (SLN) in breast cancer.

Methods

Primary breast cancer, clinically axillary node-negative patients (n = 182) were prospectively enrolled from March 2015 to November 2020. ICG, methylene blue (MB), and RI were used to perform axillary sentinel lymph node biopsy (SLNB). The main observation index was the positivity of ICG + MB vs. RI + MB in axillary SLNB; the secondary observation indicators were the axillary SLN detection rate, mean number of axillary SLNs detected, mean number of metastatic axillary SLNs detected, and safety.

Results

All 182 patients had axillary SLNs; a total of 925 axillary SLNs were detected. Pathological examination confirmed metastatic axillary SLN in 42 patients (total of 79 metastatic SLNs). Positivity, detection rate of SLNs, detection rate of metastatic SLNs, and the number of metastatic SLNs detected were comparable with RI+MB and ICG+MB (p > 0.05). The mean number of axillary SLNs detected was significantly higher with ICG+MB than with RI+MB (4.99 ± 2.42 vs. 4.02 ± 2.33, p < 0.001). No tracer-related adverse events occurred.

Conclusions

ICG appears to be a safe and effective axillary SLN tracer, and a feasible alternative to RI in combined imaging for axillary SLN of breast cancer.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Development and Validation of an Intraoperative Nomogram to Predict Breast Cancer-Related Lymphedema Based on the Arm Lymphatics Distribution

BACKGROUND

Preoperatively determining those patients who are at high risk of encountering breast cancer-related lymphedema (BCRL) is still not well understood.

OBJECTIVE

This study aimed to develop a simple intraoperative nomogram for BCRL, incorporating a protective factor.

METHODS

Overall, 320 breast cancer patients at Zhongnan Hospital (training set) and 221 patients at Dongfeng General Hospital (external validation cohort) treated between November 2017 and December 2018 were included. Prior to axillary lymph node dissection (ALND), 1 mL (2.5 mg) of indocyanine green was administered to the area of the internal bicipital sulcus of the upper limb. The fluorescence image was obtained and the proportion of arm lymph flow above the level of the axillary vein was calculated. Multivariate logistic regression was performed using this proportion together with clinical data. A nomogram was then constructed and assessed for its discrimination and calibration ability and clinical utility in the training and external validation sets.

RESULTS

The cumulative incidence of BCRL was 18.7% (60/320), with a median follow-up of 29 months (20-34). In the multivariate logistic regression analysis, body mass index, taxane, radiotherapy, and proportion of arm lymph flow above the level of the axillary vein were identified as independent risk factors. In the training and validation cohorts, the calibration curve performed well (p = 0.721 and p = 0.315, respectively), and the area under the receiver operating characteristic curve values were 0.829 (95% confidence interval [CI] 0.773-0.885) and 0.804 (95% CI 0.732-0.877), respectively.

CONCLUSION

High-risk patients could be identified intraoperatively with this nomogram, and timely intervention could be performed with preservation of the arm lymphatics.

Sentinel lymph node detection by means of indocyanine green using the Karl Storz VITOM® fluorescence camera: a comparison between primary sentinel lymph node biopsy versus sentinel lymph node biopsy after neoadjuvant chemotherapy

PURPOSE

The usage of radioactive Technetium^99m (Tc^99m) colloid for the purpose of sentinel lymph node biopsy (SLNB) in early breast cancer is considered the gold standard in Germany. However, new tracers, such as near-infrared (NIR) imaging agents like indocyanine green (ICG) could offer an alternative in future, as they overcome drawbacks associated with radioactive Technetium^99m (Tc^99m) like limited availability, high costs and radioactivity exposure for both patients and surgeons.

METHODS

In this double-arm retrospective study, we sought to establish the usefulness of indocyanine green as an alternative or an addition to the conventional Technetium^99m (Tc^99m) in the identification of the SLN in early breast cancer.

RESULTS

Among the 161 patients who underwent primary SLNB, 34 patients had at least 1 SLN with metastasis. Among these patients with SLN metastasis, 33 had the SLN detected by ICG; while 31 had the SLN detected by Tc^99m. The conventional Technetium^99m radiotracer failed to detect 2 patients with metastasis in this Arm of the study. Among the 87 patients who underwent SLNB after NACT, 13 patients had at least 1 SLN with metastasis. Among these 13 patients with SLN metastasis, ICG and Tc^99m had detected the SLN among 12 patients, while 1 patient had been detected by ICG alone.

CONCLUSIONS

Our results show that ICG is as effective as the radioisotope for SLNB even among patients who have undergone NACT. This trial is registered with the German Clinical Trial Register, ID: DRKS00013606.

Monte Carlo Modeling of Shortwave-Infrared Fluorescence Photon Migration in Voxelized Media for the Detection of Breast Cancer

Recent progress regarding shortwave-infrared (SWIR) molecular imaging technology has inspired another modality of noninvasive diagnosis for early breast cancer detection in which previous mammography or sonography would be compensated. Although a SWIR fluorescence image of a small breast cancer of several millimeters was obtained from experiments with small animals, detailed numerical analyses before clinical application were required, since various parameters such as size as well as body hair differed between humans and small experimental animals. In this study, the feasibility of SWIR was compared against visible (VIS) and near-infrared (NIR) region, using the Monte Carlo simulation in voxelized media. In this model, due to the implementation of the excitation gradient, fluorescence is based on rational mechanisms, whereas fluorescence within breast cancer is spatially proportional to excitation intensity. The fluence map of SWIR simulation with excitation gradient indicated signals near the upper surface of the cancer, and stronger than those of the NIR. Furthermore, there was a dependency on the fluence signal distribution on the contour of the breast tissue, as well as the internal structure, due to the implementation of digital anatomical data for the Visible Human Project. The fluorescence signal was observed to become weaker in all regions including the VIS, the NIR, and the SWIR region, when fluorescence-labeled cancer either became smaller or was embedded in a deeper area. However, fluorescence in SWIR alone from a cancer of 4 mm diameter was judged to be detectable at a depth of 1.4 cm.

Conserving the lymphatics from the arm using fluorescence imaging in patients with breast cancer at high risk of postoperative lymphedema: a pilot study

Background

Postoperative lymphedema in breast cancer survivors is a serious complication that develops from axillary lymph node dissection (ALND), chemotherapy, and radiation therapy. Axillary reverse mapping (ARM) was recently introduced to reduce lymphedema. This pilot study aimed to investigate the feasibility of preserving the ARM node using fluorescence imaging for patients at high risk of lymphedema.

Methods

We prospectively screened patients with breast cancer who had pathologic node-positive disease at diagnosis and were scheduled for neoadjuvant chemotherapy (NCT). The sentinel lymph node (SLN) was identified using blue dye and radioisotope, while the ARM node was traced using indocyanine green (ICG). In cases in which SLN was negative on the intraoperative frozen section examination, the ARM node and lymphatics were preserved.

Results

Of the 20 screened patients, six whose metastatic axillary lymph node (ALN) was converted to clinically node-negative disease after NCT were enrolled. No patients experienced recurrence at 24 months postoperative. Four patients who had a preserved ARM node did not develop lymphedema. One patient whose ARM node was not preserved due to SLN identification failure did not develop postoperative lymphedema. One patient who underwent ALND without ARM node conservation because of metastatic SLN on frozen section examination developed postoperative lymphedema.

Conclusions

ARM is oncologically safe, decreases the incidence of postoperative lymphedema, and allows for the early detection of postoperative lymphedema in patients who underwent ALND. Ultimately, ARM may help improve the quality of life of patients with pathologic node-positive breast cancer.

Systematic review and meta-analysis concerning near-infrared imaging with fluorescent agents to identify the sentinel lymph node in oncology patients

Sentinel node procedures (SNP) are performed with the use of tracer-agents, mainly radio-colloid and/or blue dye. Fluorescent agents have emerged as a new tracer-agent to identify the SLN intra-operatively with near-infrared imaging. Our aim is to compare the detection rate of fluorescent agents to current "golden standards" (blue dye and/or radio-colloid) for the SNP by means of a systematic review and meta-analysis without any restrictions based on tumor type. A systematic search in PubMed, Embase and The Cochrane Library was performed. Articles that compared the detection rates of fluorescent agents with radio-colloid and/or blue dye were included. Meta-analyses were performed for breast, gynecological and dermatological cancer using a random effects model. In total 6195 articles were screened which resulted in a final inclusion of 55 articles. All studies used indocyanine green (ICG) as fluorescent agent. Meta-analyses comparing ICG with blue dye showed a significant and clinically relevant difference in detection rate in favor of ICG, for both breast, dermatological and gynecological cancer. Meta-analyses comparing ICG with radio-colloid did not show any significant differences, with the exception of ICG versus radio-colloid + blue dye for the bilateral SLN detection in gynecological cancer. Near-infrared fluorescence imaging using ICG provides a higher detection rate compared to blue dye for the SNP in a range of different tumor types. SLN detection rates of ICG are comparable to radio-colloid. Due to their complementary characteristics in terms of spatial resolution and transdermal sensitivity, we suggest to use a combination of both ICG and a radio-colloid.

Can Low-cost Indo Cyanine Green Florescence Technique for Sentinel Lymph Node Biopsy Replace Dual Dye (Radio-colloid and Blue Dye) Technique in Early Breast Cancer: A Prospective Two-arm Comparative Study

BACKGROUND

The objective of this study was to assess the detection and accuracy of sentinel lymph node (SLN) biopsy (SLNB) using the low-cost indocyanine green (ICG) fluorescence method and to compare this method with the gold standard dual-dye method (radio-colloid + methylene blue dye [MB]).

MATERIALS AND METHODS

One hundred patients with node-negative early breast cancer assessed clinically and by ultrasound axilla underwent an SLNB procedure using technetium-99m radio-colloid, MB, and ICG. The detection rate of SLNs and positive SLNs and the number of SLNs were compared. The injection safety of ICG and MB was evaluated.

RESULTS

One hundred female patients with a median age of 52.3 years participated in the study. Sixty-eight percent had a body mass index < 25, 85% presented with a palpable lump, of which 59% were in the outer quadrant. SLNs were identified in all 100 cases. A total of 290 SLNs were removed (mean, 2.9; range, 1-6). The identification rate with dual dye was 94%, whereas with ICG alone, it was 96%. The SLNB sensitivity rate and false negative rate were 97.6% versus 93.2% and 3.1% versus 6.2% in the ICG and dual-dye combination, respectively. None of the patients had any local or systemic reaction with ICG; 3 patients with blue dye had tattooing and staining of skin.

CONCLUSION

ICG fluorescence imaging permits real time visualization of lymphatics and provides an additional dimension to SLN biopsy that is safe and effective. These results confirm high sensitivity for fluorescence localization with comparable performance to the gold standard. ICG can reliably replace dual dye and be employed as a sole tracer for SLNB in early breast cancer.

Applications of near infrared and surface enhanced Raman scattering techniques in tumor imaging: A short review

Imaging technologies play a vital role in clinical oncology and have undergone massive growth over the past few decades. Research in the field of tumor imaging and biomedical diagnostics requires early detection of physiological alterations so as to provide curative treatment in real time. The objective of this review is to provide an insight about near infrared fluorescence (NIRF) and surface enhanced Raman scattering (SERS) imaging techniques that can be used to expand their capabilities for the early detection and diagnosis of cancer cells. Basic setup, principle and working of the instruments has been provided and common NIRF imaging agents as well as SERS tags are also discussed besides the analytical advantages/disadvantages of these techniques. This review can help researchers working in the field of molecular imaging to design cost effective fluorophores and SERS tags to overcome the limitations of both NIRF as well as SERS imaging technologies.

Fluorescence Guidance in Surgical Oncology: Challenges, Opportunities, and Translation

Surgical resection continues to function as the primary treatment option for most solid tumors. However, the detection of cancerous tissue remains predominantly subjective and reliant on the expertise of the surgeon. Surgery that is guided by fluorescence imaging has shown clinical relevance as a new approach to detecting the primary tumor, tumor margins, and metastatic lymph nodes. It is a technique to reduce recurrence and increase the possibility of a curative resection. While significant progress has been made in developing this emerging technology as a tool to assist the surgeon, further improvements are still necessary. Refining imaging agents and tumor targeting strategies to be a precise and reliable surgical strategy is essential in order to translate this technology into patient care settings. This review seeks to provide a comprehensive update on the most recent progress of fluorescence-guided surgery and its translation into the clinic. By highlighting the current status and recent developments of fluorescence image-guided surgery in the field of surgical oncology, we aim to offer insight into the challenges and opportunities that require further investigation.

Surgical Management of the Axilla in Breast Cancer Patients with Negative Sentinel Lymph Node: A Method to Reduce False-Negative Rate

BACKGROUND

False-negative rate (FNR) of sentinel lymph node dissection (SLND) has not been eliminated. The study was conducted to optimize the surgical resection of axilla in patients with negative sentinel lymph node (SLN) for the purpose of eradicating false-negative (FN) events of SLND.

METHODS

A total of 312 clinically node-negative patients without neoadjuvant therapy underwent SLND with indocyanine green (ICG), methylene blue and the combination of ICG and methylene blue. Axillary dissection was performed subsequently regardless of the status of SLN. Lymph nodes were sent for pathological examination separately by serial resection every 0.5 cm away from marginally visualized SLNs.

RESULTS

SLND was successfully conducted in 98.1% (306/312) of patients using methylene blue, ICG, and its combination. Further examination revealed 97 true-positive, 189 true-negative, and 13 FN results. The overall FNR was 11.8% (13/110). A horizontal line 1.5 cm away from the superior vSLN and a vertical line 1.5 cm away from the medial vSLN formed a zone of lower outer quadrant (LOQ) in axilla. Surgical resection of LOQ 'en bloc' showed a FNR of zero.

CONCLUSIONS

The surgical management of axilla may benefit negative SLN patients with potential nodal involvement, reducing the FNR of SLND to zero.

TRIAL REGISTRATION NUMBER AND AGENCY

This study was registered with the Chinese Clinical Trial Registry (ChiCTR1800014247).

Comparative study of indocyanine green combined with blue dye with methylene blue only and carbon nanoparticles only for sentinel lymph node biopsy in breast cancer

Purpose

The combination of indocyanine green and methylene blue (ICG + MB) was reported to be an efficient tracer method in sentinel lymph node biopsy (SLNB). However, whether this method is superior to MB only or carbon nanoparticles (CN) is controversial. This study was to evaluate the efficacy of the three methods in SLNB for breast cancer, and to analyze its influencing factors.

Methods

One hundred eighty patients with early breast cancer were recruited and randomly divided into 3 groups. Each group comprising of 60 patients with SLNB using ICG + MB, MB, and CN, respectively. Then the 3 groups were compared in detection rate, mean number of SLNs, and the detection rates and number of metastatic sentinel lymph nodes (SLNs).

Results

The detection rate of SLNs was 100% (60 of 60) in ICG + MB group, 96.7% (58 of 60), and 98.3% (59 of 60) in MB and CN group, respectively, with no significant difference (P = 0.362). Totally, 204 SLNs (mean ± standard deviation [SD] [range], 3.4 ± 1.4 [2–8]) were detected in ICG + MB group, 102 (1.7 ± 0.7 [0–3]) and 145 (2.4 ± 0.7 [0–6]) in MB and CN group, indicating significant difference (P < 0.001). The detection rate of metastatic SLN was 23.3% (14 of 60) in ICG + MB group, which was higher than 18.3% (11 of 60) and 20% (11 of 60) in MB and CN group, respectively, but showed no statistical significance (P = 0.788).

Conclusion

ICG + MB method was superior to MB only and CN only methods in the mean number of SLNs, thus predicting axillary lymph node metastasis more accurately. Therefore, in areas where the standard method is not available, ICG + MB may be more suitable as an alternative tracer for SLNB.

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.

A Novel Indocyanine Green Fluorescence-Guided Video-Assisted Technique for Sentinel Node Biopsy in Breast Cancer

BACKGROUND

The equipment to detect indocyanine green (ICG) fluorescence for sentinel lymph node (SLN) biopsy in breast cancer is not widely accessible nor optimal. The fluorescence appears as a poorly defined white shine on a black background, and dimmed lighting is required. The aim of this study was to assess the feasibility, accuracy and healthcare costs of a novel approach for SLN biopsy by a video-assisted ICG-guided technique.

METHODS

The technique for detecting SLN was radioisotope (RI) in 194 cases, video-assisted ICG-guided in 70 cases and a combined method in 71 cases. In the video-assisted ICG group, a full HD laparoscopic system equipped with xenon lamps was used for a laser-free detection of ICG within a colored and magnified high-resolution image.

RESULTS

Detection of ICG fluorescence using a laparoscope with a near-infrared filter provided a highly defined and colored image during SLN biopsy. SLN was identified in 100% of patients in all groups. Multiple SLNs were identified in 0.5% of RI patients, in 12.9% of ICG patients and in 14.1% of ICG + RI patients (p < 0.0001). In ICG + RI group, 95.1% of lymph nodes were radioactive and 92.7% were fluorescent. Operative times and healthcare costs were equivalent between groups.

CONCLUSIONS

Video-assisted ICG-guided technique is a feasible and surgeon-friendly method for SLN biopsy, with equivalent efficacy compared to RI, providing an accurate staging of the axilla.

Patterns of Axillary Lymph Node Metastasis in Breast Cancer: A Prospective Single-Center Study

Purpose

The recent trend in breast cancer treatment is to minimize axillary dissection. However, no pattern of axillary metastasis has been precisely established. The purpose of this study was to evaluate the metastatic lymphatic pattern using near-infrared fluorescence imaging with indocyanine green (ICG) in breast cancer with cytologically proven axillary metastasis.

Methods

This was a prospective single-center study. We evaluated 147 patients with breast cancer involving cytologically proven axillary metastasis, and compared physiological and nonphysiological lymphatic metastasis.

Results

We performed lymphatic mapping for 64 patients who exhibited level II lymphatic flow on near-infrared fluorescence imaging with ICG, and found that all had axillary metastasis: 51 patients who did not receive neoadjuvant chemotherapy (NAC) and 13 patients post-NAC. Of patients who did not receive NAC, 32 had physiological lymphatic metastasis and 19 had nonphysiological lymphatic metastasis. The risk factors for nonphysiological lymphatic metastasis were age ≥55 years, high Ki-67 index (>20%), and perinodal extension in both univariate and multivariate analysis (p<0.05).

Conclusion

Patients with identified risk factors in cytologically-proven axillary metastasis who did not receive NAC may have nonphysiological lymphatic metastasis.

Comparison of the indocyanine green dye method versus the combined method of indigo carmine blue dye with indocyanine green fluorescence imaging for sentinel lymph node biopsy in breast conservative therapy for stage ≤IIA breast cancer

BACKGROUND

Fluorescence imaging (FI) is one of the methods to identify sentinel lymph nodes (SLNs). However, the procedure is technically complicated and requires procedural skills, as SLN biopsy must be conducted in dim light conditions. As an improved version of this method, we introduced a combined method (Combined mixed dye and fluorescence; CMF) consisting of indigo carmine blue dye and FI. The direct visualization of SLNs under shadowless surgical light conditions is facilitated by the addition of the blue dye. We compared the SLN detection rates of CMF with that of the indocyanine green (ICG) dye method (ICG-D).

METHODS

A total of 202 patients with stage ≤IIA breast cancer who underwent breast conservative therapy with separate incision from January 2004 to February 2017 were reviewed. Details of the two methods are as follows: (1) ICG-D: 10 mg of ICG was used and the green-stained SLNs were resected via a 3-4 cm axillary incision; (2) CMF: A combination of 5 mg of ICG and 4-8 mg of indigo carmine was used. After a 1.5-2 cm incision was made near the point of disappearance of the fluorescence using Photodynamic Eye (PDE), the blue-stained SLNs were resected under shadowless surgical light conditions.

RESULTS

There were 92 ICG-D and 110 CMF cases. CMF resulted in a significantly higher SLN detection rate than ICG-D (96.4% vs. 83.7%; p = 0.003). This difference was particularly notable in those aged ≥60 years (98.3% vs. 74.3%) and individuals with body mass index (BMI) ≥25 kg/m² (90.3% vs. 58.3%).

CONCLUSION

CMF is an effective method to identify SLNs which is safe and efficient. CMF achieves a high SLN identification rate and most of this procedure is feasible under shadowless surgical light conditions. CMF can reliably perform SLN biopsy even in those aged ≥60 years and individuals with BMI ≥ 25 kg/m².

Sentinel Lymph Node Biopsy in Breast Cancer Patients by Means of Indocyanine Green Using the Karl Storz VITOM® Fluorescence Camera

Currently, the use of radioisotope and blue dye for sentinel lymph node biopsy (SLNB) for axillary staging in breast cancer is common. Recently, indocyanine green (ICG) has been proposed as an alternative sentinel lymph node (SLN) tracking agent. We evaluated the clinical value of ICG as an additional tracer in combination with Technetium^99m and as an alternative to Technetium^99m for the identification of SLN in 104 breast cancer patients. 21 patients had at least 1 histologically tumor-positive SLN. All 21 patients were detected by ICG; in one of these 21 sentinel-positive patients, Technetium^99m was unable to identify lymph node involvement. Our results show that ICG is as effective as the radioisotope for SLNB. In addition, as a near-infrared dye, it has the advantages of real-time visualization, lower cost, and wider availability, since no radioactive material needs to be handled. This trial is registered with German Clinical Trial Register Main ID: DRKS00013606.

Comparison between the indocyanine green fluorescence and blue dye methods for sentinel lymph node biopsy using novel fluorescence image-guided resection equipment in different types of hospitals

Sentinel lymph node biopsy (SLNB) has become a standard of care to detect axillary lymph metastasis in early-stage breast cancer patients with clinically negative axillary lymph nodes. Current SLNB detection modalities comprising a blue dye, a radioactive tracer, or a combination of both have advantages as well as disadvantages. Thus, near-infrared fluorescence imaging using indocyanine green (ICG) has recently been regarded as a novel method that has generated interest for SLNB around the world. However, the lack of appropriate fluorescence imaging systems has hindered further research and wide application of this method. Therefore, we developed novel fluorescence image-guided resection equipment (FIRE) to detect sentinel lymph nodes (SLNs). Moreover, to compare the ICG fluorescence imaging method with the blue dye method and to explore the universal feasibility of the former, a different type of hospital study was conducted. Ninety-nine eligible patients participated in the study at 3 different types of hospitals. After subcutaneous ICG allergy testing, all the patients were subcutaneously injected with methylene blue and ICG into the subareolar area. Consequently, 276 SLNs (range 1-7) were identified in 98 subjects (detection rate: 99%) by using the ICG fluorescence imaging method. In contrast, the blue dye method only identified 202 SLNs (range 1-7) in 91 subjects (detection rate: 91.92%). Besides, the results of the fluorescence imaging method were similar in the 3 hospitals. Our findings indicate the universal feasibility of the ICG fluorescence imaging method for SLNB using the fluorescence image-guided resection equipment in early breast cancer detection.

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.

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.

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.

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.

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.

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.

A review of performance of near-infrared fluorescence imaging devices used in clinical studies

Near-infrared fluorescence (NIRF) molecular imaging holds great promise as a new "point-of-care" medical imaging modality that can potentially provide the sensitivity of nuclear medicine techniques, but without the radioactivity that can otherwise place limitations of usage. Recently, NIRF imaging devices of a variety of designs have emerged in the market and in investigational clinical studies using indocyanine green (ICG) as a non-targeting NIRF contrast agent to demark the blood and lymphatic vasculatures both non-invasively and intraoperatively. Approved in the USA since 1956 for intravenous administration, ICG has been more recently used off label in intradermal or subcutaneous administrations for fluorescence imaging of the lymphatic vasculature and lymph nodes. Herein, we summarize the devices of a variety of designs, summarize their performance in lymphatic imaging in a tabular format and comment on necessary efforts to develop standards for device performance to compare and use these emerging devices in future, NIRF molecular imaging studies.

Intraoperative imaging-guided cancer surgery: from current fluorescence molecular imaging methods to future multi-modality imaging technology

Cancer is a major threat to human health. Diagnosis and treatment using precision medicine is expected to be an effective method for preventing the initiation and progression of cancer. Although anatomical and functional imaging techniques such as radiography, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) have played an important role for accurate preoperative diagnostics, for the most part these techniques cannot be applied intraoperatively. Optical molecular imaging is a promising technique that provides a high degree of sensitivity and specificity in tumor margin detection. Furthermore, existing clinical applications have proven that optical molecular imaging is a powerful intraoperative tool for guiding surgeons performing precision procedures, thus enabling radical resection and improved survival rates. However, detection depth limitation exists in optical molecular imaging methods and further breakthroughs from optical to multi-modality intraoperative imaging methods are needed to develop more extensive and comprehensive intraoperative applications. Here, we review the current intraoperative optical molecular imaging technologies, focusing on contrast agents and surgical navigation systems, and then discuss the future prospects of multi-modality imaging technology for intraoperative imaging-guided cancer surgery.

Comparison of the indocyanine green fluorescence and blue dye methods in detection of sentinel lymph nodes in early-stage breast cancer

PURPOSE

To assess the diagnostic performance of sentinel lymph node (SLN) biopsy using the indocyanine green (ICG) fluorescence method compared with that using the blue dye method, a prospective multicenter study was performed.

METHODS

Patients with T1-3 primary breast cancer without clinical lymph node involvement were included in this study. ICG as a fluorescence-emitting source and indigo carmine as blue dye were injected into the subareolar area. Extracted lymph nodes were examined to identify the first, second, and other SLNs. The identified nodes were classified according to the ICG fluorescence signal and blue dye uptake.

RESULTS

Ninety-nine eligible patients were included in this study. The ICG fluorescence method identified an average of 3.4 SLNs (range, 1-8) in 98 of 99 patients (detection rate, 99 %). The number of lymph nodes identified by the fluorescence method was significantly higher than that identified by the blue dye method (p < 0.001). SLN involvement was identified in 20 % (20 of 99) of patients, all of whom tested positive for the first SLN. In 16 patients, complete axillary lymph node dissection (ALND) was performed. In 25 % (4 of 16) of these patients, axillary metastases were identified; however, no axillary involvement was found in 8 patients with only one involved node, which was isolated as the first SLN.

CONCLUSIONS

High rate of SLN detection was achieved using the ICG fluorescence method. The first SLN identified by fluorescence imaging provides an exact indication of the axillary status. Therefore, the ICG fluorescence method provides precise information required to avoid unnecessary ALND.

Use of indocyanine green for detecting the sentinel lymph node in breast cancer patients: from preclinical evaluation to clinical validation

Assessment of the sentinel lymph node (SLN) in patients with early stage breast cancer is vital in selecting the appropriate surgical approach. However, the existing methods, including methylene blue and nuclides, possess low efficiency and effectiveness in mapping SLNs, and to a certain extent exert side effects during application. Indocyanine green (ICG), as a fluorescent dye, has been proved reliable usage in SLN detection by several other groups. In this paper, we introduce a novel surgical navigation system to detect SLN with ICG. This system contains two charge-coupled devices (CCD) to simultaneously capture real-time color and fluorescent video images through two different bands. During surgery, surgeons only need to follow the fluorescence display. In addition, the system saves data automatically during surgery enabling surgeons to find the registration point easily according to image recognition algorithms. To test our system, 5 mice and 10 rabbits were used for the preclinical setting and 22 breast cancer patients were utilized for the clinical evaluation in our experiments. The detection rate was 100% and an average of 2.7 SLNs was found in 22 patients. Our results show that the usage of our surgical navigation system with ICG to detect SLNs in breast cancer patients is technically feasible.

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.

Near infrared fluorescent chlorophyll nanoscale liposomes for sentinel lymph node mapping

BACKGROUND

Sentinel lymph node (SLN) mapping using in vivo near infrared fluorescence imaging has attracted great attention during the past few years. Here we report on the early use of poorly water-soluble chlorophyll with near infrared fluorescence extracted from the leaf of Chimonanthus salicifolius, for mouse axillary SLN mapping.

METHODS AND RESULTS

To improve the water solubility and SLN targeting of the chlorophyll, we encapsulated the chlorophyll in nanoscale liposomes. The liposome-coated chlorophyll nanocomposites obtained were spherical in shape and had an average diameter of 21.7 ± 6.0 nm. The nanocomposites dispersed well in water, and in aqueous suspension they exhibited brighter near infrared fluorescence than chlorophyll alone. After incubation of the nanocomposites with normal liver cells (QSG-7701) and macrophage cells (Ana-1) for no more than 48 hours, there was no obvious reduction in cell viability. When the nanocomposites were injected intradermally into the paw of a mouse, the axillary SLN was found to be strongly fluorescent and was easily visualized in real time without a requirement for surgery. The intensity of the near infrared fluorescence emitted by the SLN was obviously brighter than that emitted by the SLN of another mouse that had been intradermally injected with chlorophyll alone.

CONCLUSION

Our data show that the liposome-coated chlorophyll nanocomposites could have great potential for clinical SLN mapping due to their lack of toxicity, bright near infrared fluorescence, and small diameter.

A feasibility study (ICG-10) of indocyanine green (ICG) fluorescence mapping for sentinel lymph node detection in early breast cancer

BACKGROUND

There is now increasing evidence to support the use of indocyanine green (ICG) for sentinel lymph node (SLN) detection in early breast cancer. The primary objective of this feasibility study (ICG-10) was to determine the sensitivity and safety of ICG fluorescence imaging in sentinel lymph node identification when combined with blue dye and radiocolloid.

METHODS

One hundred women with clinically node negative breast cancer (95 unilateral; 5 bilateral) had sentinel lymph node (SLN) biopsy using blue dye, radioisotope and ICG. One patient was excluded from analysis and sensitivity, or detection rate, of ICG alone, and in combination with blue dye and/or radioisotope, was calculated for the remaining 104 procedures in 99 patients.

RESULTS

Transcutaneous fluorescent lymphography was visible in all 104 procedures. All 202 true SLNs, defined as blue and/or radioactive, were also fluorescent with ICG. Detection rates were: ICG alone 100%, ICG & blue dye 95.0%, ICG & radioisotope 77.2%, ICG & blue dye & radioisotope 73.1%. Metastases were found in 25 of 201 SLNs (12.4%) and all positive nodes were fluorescent, blue and radioactive. The procedural node positivity rate was 17.3%.

CONCLUSION

The results of this study confirm the high sensitivity of ICG fluorescence for SLN detection in early breast cancer. The combination of ICG and blue dye had the highest nodal sensitivity at 95.0% defining a dual approach to SLN biopsy that avoids the need for radioisotope.

Prediction of axillary lymph node metastasis in primary breast cancer patients using a decision tree-based model

Background

The aim of this study was to develop a new data-mining model to predict axillary lymph node (AxLN) metastasis in primary breast cancer. To achieve this, we used a decision tree-based prediction method—the alternating decision tree (ADTree).

Methods

Clinical datasets for primary breast cancer patients who underwent sentinel lymph node biopsy or AxLN dissection without prior treatment were collected from three institutes (institute A, n = 148; institute B, n = 143; institute C, n = 174) and were used for variable selection, model training and external validation, respectively. The models were evaluated using area under the receiver operating characteristics (ROC) curve analysis to discriminate node-positive patients from node-negative patients.

Results

The ADTree model selected 15 of 24 clinicopathological variables in the variable selection dataset. The resulting area under the ROC curve values were 0.770 [95% confidence interval (CI), 0.689–0.850] for the model training dataset and 0.772 (95% CI: 0.689–0.856) for the validation dataset, demonstrating high accuracy and generalization ability of the model. The bootstrap value of the validation dataset was 0.768 (95% CI: 0.763–0.774).

Conclusions

Our prediction model showed high accuracy for predicting nodal metastasis in patients with breast cancer using commonly recorded clinical variables. Therefore, our model might help oncologists in the decision-making process for primary breast cancer patients before starting treatment.