Background
During laparoscopic cholecystectomy, common bile duct (CBD) injury is a rare but severe complication. To reduce the risk of injury, near-infrared (NIR) fluorescent cholangiography using ...indocyanine green (ICG) has recently been introduced as a novel method of visualizing the biliary system during surgery. To date, several studies have shown feasibility of this technique; however, liver background fluorescence remains a major problem during fluorescent cholangiography. The aim of the current study was to optimize ICG dose and timing for NIR cholangiography using a quantitative intraoperative camera system during open hepatopancreatobiliary (HPB) surgery. Subsequently, these results were validated during laparoscopic cholecystectomy using a laparoscopic fluorescence imaging system.
Methods
Twenty-seven patients who underwent NIR imaging using the Mini-FLARE image-guided surgery system during open HPB surgery were analyzed to assess optimal dosage and timing of ICG administration. ICG was intravenously injected preoperatively at doses of 5, 10, and 20 mg, and imaged at either 30 min (early) or 24 h (delayed) post-injection. Next, the optimal doses found for early and delayed imaging were applied to two groups of seven patients (
n
= 14) undergoing laparoscopic NIR fluorescent cholangiography during laparoscopic cholecystectomy.
Results
Median liver-to-background contrast was 23.5 (range 22.1–35.0), 16.8 (range 11.3–25.1), 1.3 (range 0.7–7.8), and 2.5 (range 1.3–3.6) for 5 mg/30 min, 10 mg/30 min, 10 mg/24 h, and 20 mg/24 h, respectively. Fluorescence intensity of the liver was significantly lower in the 10 mg delayed-imaging dose group compared with the early imaging 5 and 10 mg dose groups (
p
= 0.001), which resulted in a significant increase in CBD-to-liver contrast ratio compared with the early administration groups (
p
< 0.002). These findings were qualitatively confirmed during laparoscopic cholecystectomy.
Conclusion
This study shows that a prolonged interval between ICG administration and surgery permits optimal NIR cholangiography with minimal liver background fluorescence.
Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has the potential to improve the sentinel lymph node (SLN) procedure by facilitating percutaneous and intraoperative ...identification of lymphatic channels and SLNs. Previous studies suggested that a dose of 0.62 mg (1.6 mL of 0.5 mM) ICG is optimal for SLN mapping in breast cancer. The aim of this study was to evaluate the diagnostic accuracy of NIR fluorescence for SLN mapping in breast cancer patients when used in conjunction with conventional techniques. Study subjects were 95 breast cancer patients planning to undergo SLN procedure at either the Dana-Farber/Harvard Cancer Center (Boston, MA, USA) or the Leiden University Medical Center (Leiden, the Netherlands) between July 2010 and January 2013. Subjects underwent the standard-of-care SLN procedure at each institution using
99
Technetium-colloid in all subjects and patent blue in 27 (28 %) of the subjects. NIR fluorescence-guided SLN detection was performed using the Mini-FLARE imaging system. SLN identification was successful in 94 of 95 subjects (99 %) using NIR fluorescence imaging or a combination of both NIR fluorescence imaging and radioactive guidance. In 2 of 95 subjects, radioactive guidance was necessary for initial in vivo identification of SLNs. In 1 of 95 subjects, NIR fluorescence was necessary for initial in vivo identification of SLNs. A total of 177 SLNs (mean 1.9, range 1–5) were resected: 100 % NIR fluorescent, 88 % radioactive, and 78 % (of 40 nodes) blue. In 2 of 95 subjects (2.1 %), SLNs-containing macrometastases were found only by NIR fluorescence, and in one patient this led to upstaging to N1. This study demonstrates the safe and accurate application of NIR fluorescence imaging for the identification of SLNs in breast cancer patients, but calls into question what technique should be used as the gold standard in future studies.
Purpose Near infrared fluorescence imaging is a promising technique that offers real-time visual information during surgery. In this study we report the first clinical results to our knowledge of ...ureteral imaging using near infrared fluorescence after a simple peripheral infusion of methylene blue. Furthermore, we assessed the optimal timing and dose of methylene blue. Materials and Methods A total of 12 patients who underwent lower abdominal surgery were included in this prospective feasibility study. Near infrared fluorescence imaging was performed using the Mini-FLARE™ imaging system. To determine optimal timing and dose, methylene blue was injected intravenously at doses of 0.25, 0.5 or 1 mg/kg after exposure of the ureters. Imaging was performed for up to 60 minutes after injection. Results In all patients both ureters could be clearly visualized within 10 minutes after infusion of methylene blue. The signal lasted at least up to 60 minutes after injection. The mean signal-to-background ratio of the ureter was 2.27 ± 1.22 (4), 2.61 ± 1.88 (4) and 3.58 ± 3.36 (4) for the 0.25, 0.5 and 1 mg/kg groups, respectively. A mixed model analysis was used to compare signal-to-background ratios among dose groups and times, and to assess the relationship between dose and time. A significant difference among time points (p <0.001) was found. However, no difference was observed among dose groups (p = 0.811). Conclusions This study demonstrates the first successful use of near infrared fluorescence using low dose methylene blue for the identification of the ureters during lower abdominal surgery.
Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has recently been introduced to improve the sentinel lymph node (SLN) procedure. Several optical tracers have been successfully ...tested. However, the optimal tracer formulation is still unknown. This study evaluates the performance of ICG-technetium-99m (99mTc)-nanocolloid in relation to 2 most commonly used ICG-based formulas during SLN biopsy in vulvar cancer.
Twelve women who planned to undergo SLN biopsy for stage I vulvar cancer were prospectively included. Sentinel lymph node mapping was performed using the dual-modality radioactive and NIR fluorescence tracer ICG-99mTc-nanocolloid. All patients underwent combined SLN localization using NIR fluorescence and the (current) gold standard using blue dye and radioactive guidance.
In all 12 patients, at least 1 SLN was detected during surgery. A total of 21 lymph nodes (median 2; range, 1-3) were resected. Median time between skin incision and first SLN detection was 8 (range, 1-22) minutes. All resected SLNs were both radioactive and fluorescent, although only 13 (62%) of 21 SLNs stained blue. Median brightness of exposed SLNs, expressed as signal-to-background ratio, was 5.4 (range, 1.8-11.8). Lymph node metastases were found in 3 patients.
Near-infrared fluorescence-guided SLN mapping is feasible and outperforms blue dye staining. Premixing ICG with 99mTc-nanocolloid provides real-time intraoperative imaging of the SN and seems to be the optimal tracer combination in terms of intraoperative detection rate of the SN (100%). Moreover, ICG-99mTc-nanocolloid allows the administration of a 5-times lower injected dose of ICG (compared with ICG and ICG absorbed to human serum albumin) and can be injected up to 20 hours before surgery.
Summary Objectives Elective neck dissection is frequently performed during surgery in head and neck cancer patients. The sentinel lymph node (SLN) procedure can prevent the morbidity of a neck ...dissection and improve lymph node staging by fine pathology. Near-infrared (NIR) fluorescence imaging is a promising technique to identify the sentinel lymph node (SLN) intraoperatively. This feasibility study explored the use of indocyanine green adsorbed to human serum albumin (ICG:HSA) for SLN mapping in head and neck cancer patients. Materials and methods A total of 10 consecutive patients with oral cavity or oropharyngeal cancer and a clinical N0 neck were included. After exposure of the neck, 1.6 mL of ICG:HSA (500 μM) was injected at four quadrants around the tumor. During the neck dissection, levels I–IV were measured for fluorescence using the Mini-FLARE imaging system. Results In all 10 patients, NIR fluorescence imaging enabled visualization of one or more SLNs. A total of 17 SLNs were identified. The mean contrast between the fluorescent signal of the lymph nodes and of the surrounding tissue was 8.7 ± 6.4. In 3 patients, of which 1 was false-negative, lymph node metastases were found. After administration of ICG:HSA, the average number of fluorescent lymph nodes significantly increased over time ( P < 0.001). Conclusion This study demonstrated feasibility to detect draining lymph nodes in head and neck cancer patients using NIR fluorescence imaging. However, the fluorescent tracer quickly migrated beyond the SLN to higher tier nodes.
Background
Irradical tumor resections and iatrogenic ureteral injury remain a significant problem during lower abdominal surgery. The aim of the current study was to intraoperatively identify both ...colorectal tumors and ureters in subcutaneous and orthotopic animal models using cRGD-ZW800-1 and near-infrared (NIR) fluorescence.
Methods
The zwitterionic fluorophore ZW800-1 was conjugated to the tumor specific peptide cRGD (targeting integrins) and to the a-specific peptide cRAD. One nmol cRGD-ZW800-1, cRAD-ZW800-1, or ZW800-1 alone was injected in mice bearing subcutaneous HT-29 human colorectal tumors. Subsequently, cRGD-ZW800-1 was injected at dosages of 0.25 and 1 nmol in mice bearing orthotopic HT-29 tumors transfected with luciferase2. In vivo biodistribution and ureteral visualization were investigated in rats. Fluorescence was measured intraoperatively at several time points after probe administration using the FLARE imaging system.
Results
Both subcutaneous and orthotopic tumors could be clearly identified using cRGD-ZW800-1. A significantly higher signal-to-background ratio was observed in mice injected with cRGD-ZW800-1 (2.42 ± 0.77) compared with mice injected with cRAD-ZW800-1 or ZW800-1 alone (1.21 ± 0.19 and 1.34 ± 0.19, respectively) when measured at 24 h after probe administration. The clearance of cRGD-ZW800-1 permitted visualization of the ureters and also generated minimal background fluorescence in the gastrointestinal tract.
Conclusions
This study appears to be the first to demonstrate both clear tumor demarcation and ureteral visualization after a single intravenous injection of a targeted NIR fluorophore. As a low dose of cRGD-ZW800-1 provided clear tumor identification, clinical translation of these results should be possible.
Abstract Near-infrared (NIR) fluorescence imaging has emerged as a promising complimentary technique for intraoperative visualization of tumor tissue, lymph nodes and vital structures. In this ...review, the current applications and future opportunities of NIR fluorescence imaging in gynecologic oncology are summarized. Several studies indicate that intraoperative sentinel lymph node identification in vulvar cancer using NIR fluorescence imaging outperforms blue dye staining and provides real-time intraoperative imaging of sentinel lymph nodes. NIR fluorescence imaging can penetrate through several millimeters of tissue, revealing structures just below the tissue surface. Hereby, iatrogenic damage to vital structures, such as the ureter or nerves may be avoided by identification using NIR fluorescence imaging. Tumor-targeted probes are currently being developed and have the potential to improve surgical outcomes of cytoreductive and staging procedures, in particular in ovarian cancer. Research in the near future will be necessary to determine whether this technology has additional value in order to facilitate the surgical procedure, reduce morbidity and improve disease-free and overall survival.
Abstract Objective Near-infrared fluorescence imaging using indocyanine green (ICG) has recently been introduced as a novel technique for sentinel lymph node (SLN) mapping in early-stage cervical ...cancer. Although preclinical research has shown that ICG adsorbed to human serum albumin (ICG:HSA) improves its performance, the need for HSA has not yet been confirmed in cervical cancer patients. The current randomized study aims to determine whether ICG:HSA offers advantages over using ICG alone. Methods Eighteen consecutive early-stage cervical cancer patients scheduled to undergo pelvic lymphadenectomy were included. Prior to surgery, 1.6 mL of 500 μM ICG:HSA or 500 μM ICG alone was injected transvaginally in 4 quadrants around the tumor. The Mini-FLARE imaging system was used for intraoperative NIR fluorescence detection and quantitation. Results SLNs were identified intraoperatively in 78% of the patients. Patient and tumor characteristics were equally distributed over both treatment groups. No significant difference in signal-to-background ratio (9.3 vs. 10.1, P = .72) or average number of detected SLNs (2.9 vs 2.7, P = .84) was found between the ICG:HSA group and the ICG alone group, respectively. Conclusions In conclusion, this double-blind, randomized trial showed no advantage of ICG:HSA over ICG alone for the SLN procedure in early-stage cervical cancer. Further optimization is required to improve the intraoperative detection rate.
Background
Improved imaging methods and surgical techniques have created a new era in hepatopancreatobiliary (HPB) surgery. Despite these developments, visual inspection, palpation, and ...intraoperative ultrasound remain the most utilized tools during surgery today. This is problematic, though, especially in laparoscopic HPB surgery, where palpation is not possible. Optical imaging using near-infrared (NIR) fluorescence can be used for the real-time assessment of both anatomy (e.g., sensitive detection and demarcation of tumours and vital structures) and function (e.g., assessment of luminal flow and tissue perfusion) during both open and minimally invasive surgeries.
Methods
This article reviews the published literature related to preclinical development and clinical applications of NIR fluorescence imaging during HPB surgery.
Results
NIR fluorescence imaging combines the use of otherwise invisible NIR fluorescent contrast agents and specially designed camera systems, which are capable of detecting these contrast agents during surgery. Unlike visible light, NIR fluorescent light can penetrate several millimetres through blood and living tissue, thus providing improved detectability. Applications of this technique during HPB surgery include tumour imaging in liver and pancreas, and real-time imaging of the biliary tree.
Conclusions
NIR fluorescence imaging is a promising new technique that may someday improve surgical accuracy and lower complications.
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