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

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

BACKGROUND

Hepatoblastoma and HCC are the most common malignant hepatocellular tumors seen in children. The aim of this study was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide real-time information about tumor response to therapy.

METHODS

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye used clinically to identify malignant liver cells during surgery. We assessed ICG accumulation in cell lines using fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, including ICG, Glypican-3, and DAPI, and tested it with cell lines and noncancer control blood samples. We then used this panel to analyze whole-blood samples for CTC burden with a cohort of 15 patients with hepatoblastoma and HCC and correlated with patient characteristics and outcomes.

RESULTS

We showed that ICG accumulation is specific to liver cancer cells, compared to nonmalignant liver cells, non-liver solid tumor cells, and other nonmalignant cells, and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/Glypican-3/DAPI panel showed that it specifically tagged malignant liver cells. Using patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

CONCLUSIONS

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically detect and quantify CTCs in the blood of pediatric patients with liver cancer.

Optimization of Indocyanine Green for Intraoperative Fluorescent Image-Guided Localization of Lung Cancer; Analysis Based on Solid Component of Lung Nodule

ICG fluorescence imaging has been used to detect lung cancer; however, there is no consensus regarding the optimization of the indocyanine green (ICG) injection method. The aim of this study was to determine the optimal dose and timing of ICG for lung cancer detection using animal models and to evaluate the feasibility of ICG fluorescence in lung cancer patients. In a preclinical study, twenty C57BL/6 mice with footpad cancer and thirty-three rabbits with VX2 lung cancer were used. These animals received an intravenous injection of ICG at 0.5, 1, 2, or 5 mg/kg, and the cancers were detected using a fluorescent imaging system after 3, 6, 12, and 24 h. In a clinical study, fifty-one patients diagnosed with lung cancer and scheduled to undergo surgery were included. Fluorescent images of lung cancer were obtained, and the fluorescent signal was quantified. Based on a preclinical study, the optimal injection method for lung cancer detection was 2 mg/kg ICG 12 h before surgery. Among the 51 patients, ICG successfully detected 37 of 39 cases with a consolidation-to-tumor (C/T) ratio of >50% (TNR: 3.3 ± 1.2), while it failed in 12 cases with a C/T ratio ≤ 50% and 2 cases with anthracosis. ICG injection at 2 mg/kg, 12 h before surgery was optimal for lung cancer detection. Lung cancers with the C/T ratio > 50% were successfully detected using ICG with a detection rate of 95%, but not with the C/T ratio ≤ 50%. Therefore, further research is needed to develop fluorescent agents targeting lung cancer.

An indocyanine green-based liquid biopsy test for circulating tumor cells for pediatric liver cancer

Background and Aims

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common malignant hepatocellular tumors seen in children. The aim of this work was to develop a liquid biopsy test for circulating tumor cells (CTCs) for these tumors that would be less invasive and provide information about the real-time state of tumors in response to therapies.

Methods

For this test, we utilized indocyanine green (ICG), a far-red fluorescent dye that is used clinically to identify malignant liver cells in the body during surgery. We assessed ICG accumulation in cell lines with fluorescence microscopy and flow cytometry. For our CTC test, we developed a panel of liver tumor-specific markers, ICG, Glypican-3 (GPC3), and DAPI and tested this panel with cell lines and non-cancer control blood samples. We then used this panel to analyze whole blood samples for CTC burden with a cohort of 14 HB and HCC patients and correlated with patient characteristics and outcomes.

Results

We showed that ICG accumulation is specific to liver cancer cells, compared to non-malignant liver cells, non-liver solid tumor cells, and non-malignant cells and can be used to identify liver tumor cells in a mixed population of cells. Experiments with the ICG/GPC3/DAPI panel showed that it specifically tagged malignant liver cells. With patient samples, we found that CTC burden from sequential blood samples from the same patients mirrored the patients' responses to therapy.

Conclusions

Our novel ICG-based liquid biopsy test for CTCs can be used to specifically count CTCs in the blood of pediatric liver cancer patients.

Impact and implications

This manuscript represents the first report of circulating tumor cells in the blood of pediatric liver cancer patients. The novel and innovative assay for CTCs shown in this paper will facilitate future work examining the relationship between CTC numbers and patient outcomes, forming the foundation for incorporation of liquid biopsy into routine clinical care for these patients.

Graphical abstract

Overview of novel liquid biopsy test for circulating tumor cells for pediatric liver cancer. Figure made with Biorender.

Favorable control of hepatocellular carcinoma with peritoneal dissemination by surgical resection using indocyanine green fluorescence imaging: a case report and review of the literature

BACKGROUND

The optimal management for peritoneal dissemination in patients with hepatocellular carcinoma remains unclear. Although several reports have described the usefulness of surgical resection, the indications should be carefully considered. Herein, we report the case of a patient with hepatocellular carcinoma with peritoneal recurrence who underwent surgical resection using an indocyanine green fluorescence navigation system and achieved favorable disease control.

CASE PRESENTATION

A 45-year-old Asian woman underwent left hemihepatectomy for a ruptured hepatocellular carcinoma. Seventeen months after the initial surgery, a single nodule near the cut surface of the liver was detected on computed tomography, along with elevation of tumor markers. The patient was diagnosed with peritoneal metastasis and underwent a surgical resection. Twelve months later, a single nodule on the dorsal side of the right hepatic lobe was detected on computed tomography, and we performed surgical resection. Indocyanine green (0.5 mg/kg) was intravenously administered 3 days before surgery, and the indocyanine green fluorescence imaging system revealed clear green fluorescence in the tumor, which helped us perform complete resection. Indocyanine green fluorescence enabled the detection of additional lesions that could not be identified by preoperative imaging, especially in the second metastasectomy. There was no further recurrence at 3 months postoperatively.

CONCLUSION

When considering surgical intervention for peritoneal recurrence in patients with hepatocellular carcinoma, complete resection is mandatory. Given that disseminated nodules are sometimes too small to be detected by preoperative imaging studies, intraoperative indocyanine green fluorescence may be an essential tool for determining the indications for surgical resection.

Outcome of Near-infrared Fluorescence-navigated Pulmonary Metastasectomy for Hepatocellular Carcinoma

OBJECTIVES

Pulmonary metastasectomy for hepatocellular carcinoma (HCC) is suitable in highly selected patients. However, complete resection is challenging in HCC patients with multiple lung metastases. We aimed to describe the clinical utility and survival outcome of indocyanine green (ICG) fluorescence-navigated resection of HCC lung metastases.

METHODS

From October 2015 to March 2021, 15 HCC patients with pulmonary metastasis underwent NIR fluorescence imaging thoracoscopic surgery. ICG was administered through peripheral veins preoperatively. All suspected lesions detected by palpation, white-light thoracoscopy or near-infrared (NIR) imaging were resected. After metastasectomy, all patients were followed up at regular intervals of 6-12 months.

RESULTS

A total of 90 metastatic HCC nodules were resected in 15 patients. All patients received sublobar resections, during which 89 lesions were removed by wedge resection and 1 lesion was managed via segmentectomy. Under NIR fluorescence imaging, 81 nodules successfully demonstrated fluorescence during the surgery, while 9 metastatic nodules were undetected. The median signal-to-background ratio (SBR) of the nodules was 3.34. Five patients died and 7 patients relapsed by the end of observation. The median overall survival (OS) and disease-free survival (DFS) were 47.1 months and 17.3 months, respectively. The 1-year OS and DFS rates were 71.1% and 57.8%, respectively.

CONCLUSIONS

ICG fluorescence imaging technology is useful for visualization of the peripheral tumours to assist in pulmonary metastasectomy for HCC. In addition, this technology has the potential to detect the small tumour that are missed in preoperative examinations, which might be beneficial for HCC patients with multiple lung metastases.

Lung Metastases: Current Surgical Indications and New Perspectives

Pulmonary metastasectomy is an established treatment that can provide improved long- term survival for patients with metastatic tumor(s) in the lung. In this mini-review, we discuss the state of the art of thoracic surgery in surgical management of lung metastases which actually occurs for a large part of surgical activity in thoracic surgery department. We describe the principles of surgical therapy that have been defined across the time, and that should remain the milestones of lung metastases treatment: a radical surgery and an adequate lymphadenectomy. We then focus on current surgical indications and report the oncological results according to the surgical approach (open vs. mini-invasive), the histological type and number of lung metastases, and in case of re-metastasectomy. Finally, we conclude with a brief overview about the future perspectives in thoracic surgery in treatment of lung metastases.

CT-guided color marking of impalpable pulmonary nodules prior to video-assisted thoracoscopic surgery

OBJECTIVES

To investigate the utility and complications of computed tomography (CT)-guided color marking of impalpable pulmonary nodules for video-assisted thoracoscopic surgical resection.

METHODS

This retrospective single institutional study has obtained Institutional Review Board approval. A total of 174 patients with 207 undiagnosed peripheral lesions of the lung were enrolled who had undergone preoperative computed tomography-guided color marking using colored collagen followed by video-assisted thoracoscopic surgery (VATS) from December 2015 to September 2018.

RESULTS

All nodules (mean 14.0 mm, range 3.0-30.0 mm) were successfully marked by computed tomography-guided color marking, and 96.0% cases (167/174) were localized by means of intraoperative fluoroscopy as clear spots. Minor pneumothorax with a median volume of 3.8 mL (range 0.2-119.0 mL) occurred in 12 patients (6.9%) who were completely asymptomatic and were not in serious condition. No patient required a chest tube. No major bleeding complication occurred, and no air emboli were seen. No intra- or post-operative mortality of VATS was observed.

CONCLUSIONS

Preoperative CT-guided color marking of impalpable pulmonary nodules is a safe and effective procedure that allows for successful surgical resection.

Indocyanine green fluorescence imaging for resection of pulmonary metastasis of hepatocellular carcinoma

Background

Indocyanine green (ICG) accumulates in hepatocellular carcinoma (HCC), and tumor fluorescence can be observed under irradiation with near infrared light (NIR). This study investigated the clinical utility of ICG fluorescence imaging during resection of pulmonary metastases of HCC.

Methods

From April 2010 to June 2018, six patients with suspected pulmonary metastasis of HCC were enrolled prospectively. Prior to surgery, all patients underwent the ICG hepatic function test following intravenous administration of ICG (0.5 mg/kg body weight). During surgery, metastatic HCC was identified by observation of ICG fluorescence, allowing assessment of the surgical margin. Tumor fluorescence was also evaluated on cut sections.

Results

A total of 11 metastatic HCCs were resected in six patients at nine operations. Eight lesions were removed by wedge resection and 3 lesions were managed by lobectomy. During surgery, tumor fluorescence could be confirmed through the visceral pleura in 6 out of 7 lesions treated by wedge resection, while NIR irradiation was difficult for 1 lesion. For these 6 lesions, the median distance from the tumor to the visceral pleura and the median surgical margin were 0 mm (range, 0-2 mm) and 14 mm (range, 11-17 mm), respectively. When cut sections were examined, all tumors emitted fluorescence. All lesions were histologically confirmed to be metastatic HCC.

Conclusions

In patients with pulmonary metastasis of HCC, ICG fluorescence imaging is useful for identifying the tumor and securing its margin when the lesion is peripheral and wedge resection is planned.

Indocyanine green fluorescence-navigated laparoscopic metastasectomy for peritoneal metastasis of hepatocellular carcinoma: a case report

Background

Indocyanine green (ICG) can selectively accumulate in primary hepatocellular carcinoma (HCC) and its extrahepatic metastases. ICG fluorescence imaging is an extremely sensitive intraoperative tool for detecting HCC foci and can be used to detect impalpable tumors in laparoscopic surgery. Here, we report a case of a 75-year-old man who underwent peritoneal metastasis resection of HCC using a laparoscopic near-infrared imaging system and ICG fluorescence-navigated surgery.

Case presentation

A 75-year-old man was referred to our department for peritoneal metastasis resection of HCC. Two years before admission, he had undergone transarterial embolization and segmentectomy of segment 6 with open surgery for ruptured HCC. Computed tomography revealed a 12-mm peritoneal metastatic lesion on the abdominal wall near the cut surface of the liver. No other metastases were observed; resection of the solitary metastasis was scheduled. ICG (0.5 mg/kg body weight) was intravenously injected, 72 h preoperatively. An endoscopic, ICG near-infrared fluorescence imaging system revealed clear green fluorescence, indicating peritoneal metastasis of HCC on the abdominal wall. The tumor was resected with adequate surgical margin by partially resecting the liver and diaphragm, followed by histological confirmation as peritoneal metastasis of HCC. No recurrence was observed after 12 months of follow-up.

Conclusions

ICG fluorescence can be useful in laparoscopic surgery for identifying peritoneal metastasis.

Image-guided surgery and therapy for lung cancer: a critical review

Of the many imaging technologies, some have the potential to be used in image-guided surgery and therapy (IGS/IGT). This review of relevant papers on IGS/IGT for lung cancer indicates effective localization and IGS/IGT in early endobronchial lesions by fluorescence bronchoscopic technique. Visualization of early peripheral (nodular) tumors at operation can be achieved by a variety of imaging methods and devices which allow identification, localization and provision of intraoperative real-time images. Recent developments employing fluorescence contrasts and near infra-red light have shown encouraging feasibility and outcome in providing reliable methods for the IGS of cancer generally and lung cancer more specifically with provision of real time intraoperative imaging. The concept of the hybrid operating theater is touched upon.

Intraoperative indocyanine green fluorescent angiography-assisted modified superior gluteal artery perforator flap for reconstruction of sacral pressure sores

Pressure sores are often observed in patients who are bedridden. They can be a severe problem not only for patients and their caregivers but also for plastic surgeons. Here, we describe a new method of superior gluteal artery perforator flap harvesting and anchoring with the assistance of intraoperative indocyanine green fluorescent angiography. In this report, we describe the procedure and outcomes for 19 patients with grades III and IV sacral pressure sores who underwent the operation between September 2015 and November 2016. All flaps survived, and two experienced wound-edge partial dehiscence. With the assistance of this imaging device, we were able to acquire a reliable superior gluteal artery perforator flap and perform modified operations with it that are safe, easy to learn and associated with fewer complications than are traditional.

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.