Utility and pitfalls of sentinel node identification using indocyanine green during segmentectomy for cT1N0M0 non-small cell lung cancer

Monomeric or Homodimer Conjugates of Fibroblast Activation Protein Inhibitor and Cyanine 7 Bearing a Meso-Chloride as Near-Infrared Fluorescence Probes: Design, Synthesis, and Comparative In Vivo Imaging of Distinct Breast Cancer Subtypes

Intraoperative fluorescence navigation can illuminate the tumor, directing surgeons to accurately achieve negative margins, which not only reduces recurrence but also minimizes the incidence of complications. Herein, we developed two near-infrared fluorescent probes FAPI-Cy7-Cl (Emmax = 820 nm) and (FAPI)2-Cy7-Cl (Emmax = 823 nm) with prolonged tumor retention (>72 h) and high target-to-background ratios (up to 4.5) based on the conjugation of pan-cancer targeted fibroblast activation protein inhibitor (FAPI) and the "tumor-seeking" Cyanine 7 bearing a meso-chloride and a cyclohexenyl skeleton (Cy7-Cl). Specifically, FAPI-Cy7-Cl exhibited superior imaging performance in both estrogen receptor α positive breast cancer (MCF-7) and triple-negative breast cancer (TNBC) (MDA-MB-231) subtypes in mouse models. Notably, in the MDA-MB-231 tumor-bearing model, the tumor-to-liver ratio (T/L) of FAPI-Cy7-Cl increased rapidly after 2 h postinjection, reaching nearly 4.5 at 48 h, making it an optimal imaging probe for guiding TNBC surgery resection.

Intraoperative sentinel lymph node mapping with indocyanine green via video-assisted thoracoscopic surgery for primary pulmonary neoplasia in a dog

OBJECTIVE

To report the use of intraoperative sentinel lymph node (SLN) mapping with indocyanine green (ICG) and near-infrared (NIR) imaging in a dog with a primary pulmonary carcinoma that underwent lung lobectomy via a video-assisted thoracoscopic approach.

STUDY DESIGN

Case report.

ANIMALS

A 9-year-old female spayed Labrador retriever.

METHODS

A solitary, 6.5 cm diameter, right caudal pulmonary mass was identified on contrast-enhanced thoracic and abdominal computed tomography, with no overt metastatic disease or other primary neoplastic diseases. The dog underwent video-assisted thoracoscopic surgery. A right-sided thoracoscopic approach was initially performed for right caudal pulmonary ligament transection and image-guided peritumoral (intrapulmonary) ICG injection. Due to the large size of the mass, a wound retractor was then placed in the right 6th intercostal space for right caudal lung lobectomy. Sentinel lymph node mapping was performed via NIR imaging, and the SLN was extirpated for histologic assessment.

RESULTS

The right tracheobronchial lymph node was identified as sentinel via NIR fluorescence following peritumoral ICG injection. Right caudal lung lobectomy and right tracheobronchial lymph node extirpation were performed without complication, and histologic evaluation revealed a grade 1 pulmonary adenocarcinoma with pneumonia and a reactive lymph node.

CONCLUSION

Peritumoral ICG administration with NIR imaging appears to be an effective method for intraoperative SLN mapping in dogs with primary pulmonary tumors. The technique utilized in this report can be applied to open or minimally invasive procedures. Large-scale studies with SLN mapping are needed to determine an accurate incidence of nodal metastatic disease and any effect of extirpation of early metastatic disease via SLN mapping techniques on oncologic outcomes in dogs with primary pulmonary carcinoma.

Indocyanine Green Fluorescence Imaging in the Surgical Management of Skin Squamous Cell Carcinoma

Introduction

Indocyanine green (ICG) fluorescence imaging has been used in the resection surgery and sentinel lymph node biopsy of many tumors. The aim of the present study is to verify the feasibility and effectiveness of ICG fluorescence imaging used for guiding the biopsy and resection of skin squamous cell carcinoma (SSCC).

Methods

Sixty patients were enrolled, including 18 patients of suspected SSCC and 42 patients of diagnosed SSCC on admission. The ICG fluorescence imaging-guided skin biopsy was performed preoperatively in the 18 cases of suspected SSCC. Fifty-three patients underwent ICG fluorescence imaging-guided radical excision.

Results

The results showed that 138 skin tissue samples in 60 patients with preoperative or intraoperative ICG fluorescence imaging-guide biopsy were collected. For a total number of 138 biopsies, 122 specimens were squamous cell carcinoma, and the accuracy rate was 88.4%, which was significantly higher than that of the group without preoperative ICG fluorescence imaging (41/62, 66.1%, P < 0.05). Fifty-three patients underwent surgery guided with ICG fluorescence imaging. Residual fluorescent signals in 24 patients were intraoperatively found and the excision was then expanded until the signals disappeared. Follow-up to November 2022, 12 patients died, of which 5 cases died from the tumor recurrence, and the others died due to advanced ages or other reasons. The recurrence rate was 9.4%, which was not significantly different from that of the group received routine radical resection (4/35, 11.4%, P > 0.05). Moreover, sentinel lymph nodes were successfully detected under ICG fluorescence imaging in the 4 patients with suspected lymph node metastases, and the location of lymph nodes can be precisely identified.

Conclusion

ICG fluorescence imaging technique can guide the pathology biopsy to improve the accuracy of pathological examination, and help to identify the boundaries of tumor tissues and sentinel lymph nodes to resect tumor radically during operation.

Use of Indocyanine Green Fluorescence Imaging in Thoracic and Esophageal Surgery

BACKGROUND

Fluorescence imaging using indocyanine green in thoracic and esophageal surgery is gaining popularity because of the potential to facilitate surgical planning, to stage disease, and to reduce postoperative complications. To optimize use of fluorescence imaging in thoracic and esophageal surgery, an expert panel sought to establish a set of recommendations at a consensus meeting.

METHODS

The panel included 12 experts in thoracic and upper gastrointestinal surgery from Asia-Pacific countries. Before meeting, 7 focus areas were defined: intersegmental plane identification for sublobar resections; pulmonary nodule localization; lung tumor detection; bullous lesion detection; lymphatic mapping of lung tumors; evaluation of gastric conduit perfusion; and lymphatic mapping in esophageal surgical procedures. A literature search of the PubMed database was conducted using keywords indocyanine green, fluorescence, thoracic, surgery, and esophagectomy. At the meeting, panelists addressed each focus area by discussing the most relevant evidence and their clinical experiences. Consensus statements were derived from the proceedings, followed by further discussions, revisions, finalization, and unanimous agreement. Each statement was assigned a level of evidence and a grade of recommendation.

RESULTS

A total of 9 consensus recommendations were established. Identification of the intersegmental plane for sublobar resections, localization of pulmonary nodules, lymphatic mapping in lung tumors, and assessment of gastric conduit perfusion were applications of fluorescence imaging that have the most robust current evidence.

CONCLUSIONS

Based on best available evidence and expert opinions, these consensus recommendations may facilitate thoracic and esophageal surgery using fluorescence imaging.

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.

Near-Infrared Fluorescence Tumor-Targeted Imaging in Lung Cancer: A Systematic Review

Lung cancer is the most common cancer type worldwide, with non-small cell lung cancer (NSCLC) being the most common subtype. Non-disseminated NSCLC is mainly treated with surgical resection. The intraoperative detection of lung cancer can be challenging, since small and deeply located pulmonary nodules can be invisible under white light. Due to the increasing use of minimally invasive surgical techniques, tactile information is often reduced. Therefore, several intraoperative imaging techniques have been tested to localize pulmonary nodules, of which near-infrared (NIR) fluorescence is an emerging modality. In this systematic review, the available literature on fluorescence imaging of lung cancers is presented, which shows that NIR fluorescence-guided lung surgery has the potential to identify the tumor during surgery, detect additional lesions and prevent tumor-positive resection margins.

Lobectomy versus segmentectomy: a propensity score-matched comparison of postoperative complications, pulmonary function and prognosis

OBJECTIVES

To demonstrate the differences in clinical outcomes between lobectomy and segmentectomy for non-small cell lung cancer using propensity score matching.

METHODS

A single-centre, retrospective, matched cohort study was conducted in clinical T1N0M0 non-small cell lung cancer patients treated by surgery between 2012 and 2019. Differences in freedom from recurrence, overall survival, postoperative complications, chest drainage and preservation of pulmonary function between lobectomy and segmentectomy were evaluated using the propensity score model. Matched variables of patients were age, sex, comorbidity index and pulmonary function. Matched variables of tumours were tumour size, T-stage, fluorodeoxyglucose uptake on positron emission tomography, histopathology, lobe site and tumour distance ratio from the hilum.

RESULTS

Of the 112 patients treated by lobectomy and 233 patients treated by segmentectomy, 93 patients each from both groups were selected after the matching. The median tumour distance ratio from hilum was 0.7 in lobectomy and 0.8 in segmentectomy group (P = 0.59), i.e. almost outer third tumour location. There were no significant differences in freedom from recurrence (P = 0.38), overall survival (P = 0.51), postoperative complications (P = 0.94), drainage period (P = 0.53) and prolonged air leakage (P = 0.82) between the two. Median preservation of pulmonary function was 93.2% after segmentectomy, which was significantly higher than 85.9% after lobectomy (P < 0.001).

CONCLUSIONS

Freedom from recurrence, overall survival, postoperative complications and chest drainage were similar between segmentectomy and lobectomy. Segmentectomy could be one of the options for clinical T1N0M0 non-small cell lung cancer located outer third as well as being able to preserve pulmonary function better than lobectomy.

CLINICAL TRIAL REGISTRATION

Development of Gold Nanorods Conjugated with Radiolabeled Anti-human Epidermal Growth Factor Receptor 2 (HER2) Monoclonal Antibody as Single-Photon Emission Computed Tomography/Photoacoustic Dual-Imaging Probes Targeting HER2-Positive Tumors

Surgery remains one of the main treatments of cancer and both precise pre- and intraoperative diagnoses are crucial in order to guide the operation. We consider that using an identical probe for both pre- and intra-operative diagnoses would bridge the gap between surgical planning and image-guided resection. Therefore, in this study, we developed gold nanorods (AuNRs) conjugated with radiolabeled anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibody, and investigated their feasibility as novel HER2-targeted dual-imaging probes for both single photon emission computed tomography (SPECT) (preoperative diagnosis) and photoacoustic (PA) imaging (intraoperative diagnosis). To achieve the purpose, AuNRs conjugated with different amount of trastuzumab (Tra) were prepared, and Tra-AuNRs were labeled with indium-111. After the evaluation of binding affinity to HER2, cell binding assay and biodistribution studies were carried out for optimization. AuNRs with moderate trastuzumab conjugation (Tra2-AuNRs) were proposed as the novel probe and demonstrated significantly higher accumulation in NCI-N87 (HER2 high-expression) tumors than in SUIT2 (low-expression) tumors 96 h post-injection along with good affinity towards HER2. Thereafter, in vitro PA imaging and in vivo SPECT imaging studies were performed. In in vitro PA imaging, Tra2-AuNRs-treated N87 cells exhibited significant PA signal increase than SUIT2 cells. In in vivo SPECT, signal increase in N87 tumors was more notable than that in SUIT2 tumors. Herein, we report that the Tra2-AuNRs enabled HER2-specific imaging, suggesting the potential as a robust HER2-targeted SPECT and PA dual-imaging probe.

Diversity of lymphatic flow in patients with lung cancer revealed by computed tomography lymphography

OBJECTIVES

This study was conducted to verify the optimal extent of lymph node dissection or sampling during lung cancer surgery based on the sentinel node (SN) map created by computed tomography (CT) lymphography.

METHODS

From April 2010 to January 2015, patients with clinical stage I non-small-cell lung cancer, who were candidates for lobectomy or segmentectomy with standard hilar and mediastinal lymph node dissection, and in whom bronchus reached the tumour, were enrolled. An ultrathin bronchoscope was inserted to the target bronchus under the guidance of virtual bronchoscopic navigation images. CT images of the chest were obtained 30 s after 2.5 ml of iopamidol was injected. SNs were identified when the maximum CT attenuation value of the lymph nodes on postcontrast CT images increased by 30 Hounsfield units or more compared with the precontrast images. Patients underwent lobectomy with standard lymph node dissection.

RESULTS

SNs were identified in 36 (87.8%) of the 41 patients. The average number of SNs was 1.6 (range, 1-4). There was 1 false negative case; therefore, the accuracy of SN identification was 97.2% (35/36). In 5 (13.9%) of 36 patients, SNs were outside the lobe-specific lymph node station range (#11i from right S1, #7 from right S1, #4R from right S8, #12u from right S8, #7 and #12l from left S1 + 2).

CONCLUSIONS

CT lymphography demonstrated the diversity of lymphatic spreading patterns and there were cases in which lymph flows are found outside the lymph node dissection range.

Extent of Segmentectomy That Achieves Greater Lung Preservation Than Lobectomy

BACKGROUND

This study sought to clarify the extent of segmentectomy that achieves greater lung preservation than lobectomy.

METHODS

This was a single-center retrospective cohort study involving 374 patients with lung cancer who were treated with either lobectomy or segmentectomy between 2013 and 2018. The percentage of preserved pulmonary function (%PPF) after surgery was compared among patients who underwent lobectomy (n = 164), segmentectomy of 2 or more segments (Seg ≥2S; n = 42), and segmentectomy of less than 2 segments (Seg <2S; n = 168). Using perfusion scintigraphy, forced expiratory volume in 1 second of the preserved target lobe was measured to examine its effect on the %PPF. The number of resected subsegments (SSs) in segmentectomy that made the %PPF higher than that observed with lobectomy was also examined.

RESULTS

Mean %PPF was lowest in those patients who underwent lobectomy (86%), followed by Seg ≥2S (89%) and Seg <2S (95%) (P < .001), but the difference between the lobectomy and Seg ≥2S was not significant (P = .21). The forced expiratory volume in 1 second of the preserved target lobe was significantly lower in the Seg ≥2S group than in the Seg <2S group (P < .001). The number of resected SSs was 6 to 12 in lobectomy, 4 to 7 in Seg ≥2S, and 1 to 4 in Seg <2S. Although the %PPF after segmentectomy of less than 5 SSs (Seg <5SS) was significantly higher than that after lobectomy (P < .001), the %PPF after segmentectomy of 5 or more SSs (Seg ≥5SS) was not significantly different from that after lobectomy (P = .68).

CONCLUSIONS

Both the Seg ≥2S and Seg ≥5SS groups did not differ from lobectomy in %PPF because of the low function of preserved target lobe.

Long-term outcomes of sentinel node identification using indocyanine green in patients with lung cancer

BACKGROUND

Sentinel node (SN) biopsy is used in the management of numerous cancers to avoid unnecessary lymphadenectomy. This was a clinical exploration/feasibility study of a novel identification technique for SN biopsy using indocyanine green (ICG) fluorescence imaging during lung cancer surgery.

METHODS

SN biopsy using ICG was performed on 22 patients who had cT1 or T2N0M0 lung cancer. ICG was injected just around the primary tumor. The fluorescence imaging system enabled visualization of the lymphatic vessels draining from the primary tumor toward the lymph nodes. Fluorescently labeled nodes were dissected, and patients were followed-up for prognosis and recurrence to confirm the pattern of lymph node metastasis after surgery.

RESULTS

SNs were successfully identified in 16 (72.7%) of 22 patients. A total of 13 of 16 patients had pathological N0 and three had SN metastasis. The median follow-up time was 92.7 months. Only one patient had no SN metastasis at the postoperative pathological examination and lymph node metastasis during the follow-up period. The accuracy rate was 93.8% (15/16) and the false-negative rate was 7.7% (1/13).

CONCLUSIONS

SNs were identified by ICG fluorescence imaging, and this technique during lung cancer surgery had good identification and accuracy rates throughout the follow-up period.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: We attempted to identify sentinel lymph nodes by indocyanine green in lung cancer surgery. The identification rate was 72.7%. The accuracy rate was 100% immediately after surgery, and 93.8% after follow-up.

WHAT THIS STUDY ADDS

Sentinel node biopsy by indocyanine green may be useful for lymph node dissection during lung cancer surgery to avoid unnecessary lymphadenectomy.

Sensitive Photoacoustic/Magnetic Resonance Dual Imaging Probe for Detection of Malignant Tumors

In order to completely remove tumors in surgeries, probes are needed both preoperatively and intraoperatively. For tumor diagnosis, magnetic resonance imaging (MRI) has been widely used as a precise preoperative method, and photoacoustic imaging (PAI) is a recently emerged intraoperative (or preoperative) method, which detects ultrasonic waves thermoelastically induced by optical absorbers irradiated by laser. Iron oxide nanoparticles (IONPs) can be used as both MR and PA imaging probes. In order to improve the sensitivity of IONPs as MR/PA imaging probes, we newly prepared liposomes encapsulated with a number of IONPs (Lipo-IONPs). Interestingly, Lipo-IONPs showed 2.6 and 3.8-times higher PA and MR signals, respectively, compared to dispersed IONPs at the same concentration. Furthermore, trastuzumab (Tra) (anti-human epidermal growth factor receptor 2 (EGFR2; HER2) monoclonal antibody) was introduced onto the surface of liposomes for detection of HER2 related to tumor malignancy. In an cellular uptake study, Tra-Lipo-IONPs were taken up by HER2-positive tumor cells and HER2-specific MR/PA dual imaging was achieved. Finally, a biodistribution study using radiolabeled Tra-Lipo-IONPs showed HER2-specific tumor accumulation. In conclusion, we demonstrated the usefulness of Lipo-IONPs as platforms for sensitive MR/PA dual imaging and the possibility of HER2-specific tumor MR/PA imaging using Tra-Lipo-IONPs.

Sentinel lymph node biopsy for lung cancer

Sentinel lymph node biopsy is a technique to identify the first lymph node (or nodes) draining a tumor. The underlying principle is that as the first site of cancer spread, evaluation of the sentinel node will be most predictive for wider nodal involvement. The introduction of sentinel node biopsy revolutionized the surgical management of cutaneous melanoma and breast cancer, becoming a key component in the management of such patients. For over 20 years, thoracic surgeons have similarly worked to apply this technique to lung cancer but have thus far not had the same impact on lung surgery. In this review, we will summarize the ongoing discussions on the role of sentinel node biopsy in lung cancer, the methods for identifying the sentinel node, and the techniques for evaluating the sentinel node specimen. We will also highlight some of the pressing questions investigators should consider when designing a trial for sentinel node mapping. This will clarify the current status of sentinel node biopsy in lung cancer and thus highlight important future directions for research.

Diagnostic accuracy of sentinel lymph node biopsy using indocyanine green in lung cancer: a systematic review and meta-analysis

OBJECTIVE

The use of sentinel lymph node biopsy (SLNB) has been gaining popularity with the emergence of indocyanine green (ICG) fluorescence imaging. We aimed to systematically review the literature and perform a meta-analysis on the diagnostic accuracy of SLNB using ICG for lung cancer.

METHODS

A comprehensive search of MEDLINE, EMBASE, SCOPUS, Web of Science, and the Cochrane Library using search terms "lung/pulmonary" AND "tumor/carcinoma/cancer/neoplasm/adenocarcinoma/malignancy/squamous/carcinoid" AND "indocyanine green" was completed in June 2018. Articles were selected based on the following inclusion criteria: (1) diagnostic accuracy study design; (2) ICG injected at the tumor site with near-infrared fluorescence imaging identification of sentinel lymph nodes; (3) lymphadenectomy or sampling was performed as the gold standard.

RESULTS

Eight primary studies were included with a total of 366 patients. 43.0% of patients were females and the mean tumor size was 2.3 cm. Sentinel lymph nodes were identified with ICG in 251 patients, yielding a pooled identification rate of 0.83 (0.67-0.94). A meta-analysis of seven studies computed a diagnostic odds ratio, sensitivity, and specificity of 177.6 (45.6-691.1), 0.85 (0.71-0.94), and 1.00 (0.98-1.00), respectively. The summary receiver operator characteristic demonstrated an area under the curve of 0.963 (SE = 0.038) and a Q* of 0.91 (SE = 0.057).

CONCLUSION

Our review found suboptimal results for the diagnostic accuracy of SLNB using ICG and must be improved before routine clinical use. Further research is required to develop a robust protocol for the use SLNB with ICG for lung cancer.

Recent fluorescence imaging technology applications of indocyanine green in general thoracic surgery

Thoracic surgeons perform a wide variety of cancer operations, which are often associated with high morbidity and mortality. Thus, thoracic surgery involves many special challenges that require innovative solutions. The increased utilization of minimally invasive practices, poor overall cancer survival, and significant morbidity of critical operations remain key obstacles to overcome. Fluorescence imaging technology (FIT), involving the implementation of fluorescent dyes and imaging systems, is currently used as an adjunct for general thoracic surgery in many situations and includes sentinel lymph node mapping, pulmonary intersegmental plane identification, pulmonary nodule identification, pulmonary bullous lesion detection, evaluation of the anastomotic perfusion after tracheal surgery, and thoracic duct imaging for postoperative chylothorax. This technology enhances the surgeon's ability to perform operations, and has specific advantages. We review some of the key studies that demonstrate the applications of FIT in the field of general thoracic surgery, focusing on the use of indocyanine green.

Is the near-infrared fluorescence imaging with intravenous indocyanine green method for identifying the intersegmental plane concordant with the modified inflation-deflation method in lung segmentectomy?

OBJECTIVES

At present, the modified inflation-deflation method is accepted and widely used in the clinic, but the near-infrared (NIR) fluorescence imaging with intravenous indocyanine green (ICG) method can also delineate the intersegmental demarcation. However, whether the two methods identify that the intersegmental plane is concordant with each other and match the real intersegmental demarcation is still unknown.

METHODS

Between March 2019 to July 2019, 19 consecutive segmentectomies were performed, using both methods to delineate the intersegmental plane, in order to evaluate and verify whether the intersegmental plane results created by the two methods were concordant and matched the real intersegmental demarcation.

RESULTS

Segmentectomies were carried out using uniportal video-assisted thoracic surgery (UVATS) successfully with no intraoperative conversions or ICG-related complications and only three cases (15.8%) with postoperative complications related to the operation. The intersegmental plane generated by the NIR fluorescence imaging with intravenous ICG method was found to be totally concordant with the modified inflation-deflation method that was approaching the real intersegmental demarcation in all 19 cases.

CONCLUSIONS

Both methods revealed the intersegmental plane clearly, and the NIR fluorescence imaging with intravenous ICG method was found to be totally concordant with the modified inflation-deflation method, which is highly concordant with the real intersegmental demarcation. NIR fluorescence imaging with intravenous ICG method may be more popular because of its safety, efficiency, and less complicated restrictions, especially in patients with pulmonary emphysema. Low doses of ICG do not affect the rate of identification of the intersegmental plane and is safer from drug toxicology.

The role of indocyanine green fluorescence for intersegmental plane identification during video-assisted thoracoscopic surgery segmentectomies

Background

According to recent studies, thoracoscopic segmentectomy is an acceptable alternative to lobectomy for treating different lung diseases. This approach appears to have equivalent rates of postoperative morbidity with potentially similar long-term results even in selected lung cancer patients. At the same time, surgical success is highly dependent on intraoperative interpretation of segmental anatomy. We aimed to analyze our lung segmentectomy experience and identify the role of indocyanine green (ICG)-fluorescence for intersegmental plane detection.

Methods

A total of 86 consecutive patients who underwent 90 thoracoscopic segmentectomies with near-infrared-indocyanine green (NIR-ICG) method between September 2015 and December 2017 were investigated. According to the preoperative 3D lung hilar model, vascular and bronchial branches of the target segment were divided. ICG was thereafter injected into the central or peripheral vein. The boundary lines between the areas with and without fluorescence was marked on the visceral pleura by electrocautery.

Results

The fluorescence was detected immediately after bolus ICG injection in the central vein in all patients but had a time delay of 10-25 seconds in cases of peripheral vein administration. The median duration of intensive ICG staining was 90 seconds, regardless of the injection method. Well-defined fluorescence borders were observed in 86 of 90 (95.6%) segmentectomies due to technical reasons in three cases and severe emphysema in one. Chronic obstructive pulmonary disease (COPD) in other patients did not impair the boundary line identification, but reduced the duration of intensive ICG staining. No ICG-related complications were observed.

Conclusions

The ICG-fluorescence technology is safe and effective for verification of anatomic segment borders for video-assisted thoracoscopic surgery (VATS). The perfusion-based ICG fluorescence technique has advantages for thoracoscopic surgeries compared to other methods. Doubling the dose of ICG allows clear detection of the intersegmental plane, even in certain suboptimal conditions.

Image-guided video-assisted thoracoscopic small lung tumor resection using near-infrared marking

BACKGROUND

Localization of non-visible, non-palpable small pulmonary nodules during video-assisted thoracoscopic surgery (VATS) remains challenging. We sought to investigate the feasibility and safety of image-guided video-assisted thoracoscopic surgery (iVATS) with near-infrared (NIR) marking in a hybrid operating room (OR).

METHODS

Both localization and surgery were performed by a single team of thoracic surgeons. Diluted indocyanine green (ICG; quantity: 0.3-0.5 mL; dye concentration: 0.125 mg/mL) was injected percutaneously to pinpoint the tumor's location under cone beam computed tomography (CBCT) guidance using a laser-guided navigation system. Real-time fluorescence images were intraoperatively obtained using a NIR thoracoscopic camera to guide subsequent resection.

RESULTS

Between March and December 2017, 26 patients underwent NIR marking of small pulmonary nodules for iVATS. The median tumor size was 7 mm (interquartile range [IQR] 5.3-10.8 mm), whereas their median distance from the pleural surface was 5 mm (IQR 0.3-10.5 mm). Seven nodules (35%) were solid, whereas 17 (65%) were ground-glass opacities. All lesions were identifiable on intraoperative CBCT. The median time required for NIR localization was 13 min. An NIR(+) "tattoo" was identified in all cases, and no intraoperative conversion to thoracotomy occurred. The final pathological diagnoses were primary lung cancer (n = 11), metastatic cancer (n = 6), and benign lung tumor (n = 9). Adverse events were not observed, and the median length of post-operative stay was 4 days (IQR 3-4 days).

CONCLUSIONS

Our data show that iVATS with NIR marking is useful, has no adverse effects, and can successfully localize difficult-to-identify small pulmonary nodules.

Photodynamic Therapy Using Indocyanine Green Loaded on Super Carbonate Apatite as Minimally Invasive Cancer Treatment

Minimally invasive treatment is getting more and more important in an aging society. The purpose of this study was to explore the possibility of ICG loaded on super carbonate apatite (sCA) nanoparticles as a novel photodynamic therapy (PDT) against cancers. Using colon cancer cells, ICG uptake and anti-tumor effects were examined between the treatments of ICG and sCA-ICG. Reactive oxygen species (ROS) production and temperature rise were also evaluated to explore the underlying mechanism. Atomic force microscopy revealed that the size of sCA-ICG ranged from 10 to 20 nm. In aqueous solution with 0.5% albumin, the temperature increase after laser irradiation was 27.1°C and 23.1°C in sCA-ICG and ICG, respectively (control DW: 5.7°C). A significant increase in ROS generation was noted in cell cultures treated with sCA-ICG plus irradiation compared with those treated with ICG plus irradiation (P < 0.01). Uptake of ICG in the tumor cells significantly increased in sCA-ICG compared with ICG in vitro and in vivo The fluorescence signals of ICG in the tumor, liver, and kidney faded away in both treatments by 24 hours. Finally, the HT29 tumors treated with sCA-ICG followed by irradiation exhibited drastic tumor growth retardation (P < 0.01), whereas irradiation of tumors after injection of ICG did not inhibit tumor growth. This study shows that sCA is a useful vehicle for ICG-based PDT. Quick withdrawal of ICG from normal organs is unique to sCA-ICG and contrasts with the other nanoparticles remaining in normal organs for a long time. Mol Cancer Ther; 17(7); 1613-22. ©2018 AACR.

Infrared intraoperative fluorescence imaging using indocyanine green in thoracic surgery

Thoracic surgery faces many unique challenges that require innovative solutions. The increase in utilization of minimally invasive practices, poor overall cancer survival and significant morbidity of key operations remain key obstacles to overcome. Intraoperative fluorescence imaging is a process by which fluorescent dyes and imaging systems are used as adjuncts for surgeons in the operating room. Other surgical subspecialists have shown that intraoperative fluorescence imaging can be applied as a practical adjunct to their practices. Thoracic surgeons over the last 15 years have also used intraoperative fluorescence imaging for sentinel lymph node mapping, lung mapping, oesophageal conduit vascular perfusion and lung nodule identification. This review describes some of the key studies that demonstrate the applications of intraoperative near-infrared fluorescence imaging.

Infrared fluorescence guided pleural biopsy during thoracoscopy

OBJECTIVE. The authors developed methods and assessment of efficacy of infrared fluorescence imaging of pleural carcinomatosis using indocyanine green (ICG). MATERIAL AND METHODS. The prospective study included 14 patients with malignant pleural carcinomatosis. All patients underwent standard thoracoscopy with pleural biopsy, then pleural cavity was examined under fluorescence control using ICG solution. Comparison of accuracy of biopsy materials obtained in white light and fluorescence was made. RESULTS. Signs of malignancy had 21 biopsy specimens out of 28, which were obtained in white light (in 12 patients out of 14). Research of biopsy specimens using fluorescence allowed doctors to make the precise diagnosis in all 14 patients, with 33 out of 34 biopsy materials being informative. CONCLUSIONS. Intraoperative application of infrared ICG fluorescence developed accuracy of biopsy and histological verification of the diagnosis.

Clinical use of near-infrared fluorescence imaging with indocyanine green in thoracic surgery: a literature review

Invisible near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has advantage in detecting for certain anatomy. The method is currently used in some types of surgery, such as sentinel lymph node (SLN) mapping, intraoperative solid tumor identification, and organ perfusion assessment. However, the literature of clinical application in thoracic surgery is lacking. This paper presents the advantages, current applications and potential developments of NIR fluorescence imaging with ICG in thoracic surgery.