Robotically assisted fluorescence-guided lymph node mapping with ICG for gynecologic malignancies: a feasibility study

Indocyanine green in gynecologic surgery: Where do we stand? A literature review and meta-analysis

The main objective of this study was to review and perform a meta-analysis of current literature on the use of indocyanine green for sentinel lymph node detection in pelvic gynecologic cancer. We included all studies focusing on indications and procedures associated with the use of ICG in gynecologic surgery and available on the Medline and Pubmed database. For the meta-analysis, random effect models were used for estimation of the 95 % detection rate and 95 % confidence interval, and stratified analyses by cancer type, concentration and localization of injection were performed. A total of 147 articles were included, of which 91 were studied in a meta-analysis. Results concerning detection rate by indocyanine green injection site were found to be 95.1 % and 97.3 % respectively for intracervical injection in 2 or 4 quadrants, and 77.0 % and 94.8 % for hysteroscopic and intradermal injection respectively. Results concerning detection rate by cancer type were 95.8 %, 95.2 %, 94.7 % and 95.7 % respectively for cervical, endometrial, vulvar and endometrial/cervical cancers. Finally, the results concerning detection rate by indocyanine green concentration were 91.2 %, 95.7 %, 96.7 % and 97.7 % for concentrations of <1.25 mg/ml, 1.25 mg/ml, 2.5 mg/ml and 5 mg/ml respectively. In conclusion, indocyanine green is shown to allow highlighting of sentinel lymph nodes with good reliability with an overall indocyanine green detection rate of 95.5 %. Our literature review revealed that indocyanine green feasibility has also been demonstrated in several surgical contexts, notably for reconstructive surgery and detection of endometriosis.

A Green Lantern for the Surgeon: A Review on the Use of Indocyanine Green (ICG) in Minimally Invasive Surgery

Indocyanine green (ICG) fluorescence imaging has revolutionized surgical practice across various medical and surgical specialties. This article reviews the clinical applications of ICG in abdominal, urological, thoracic, and gynecological surgery. ICG fluorescence imaging has been widely adopted in general surgery for various applications, including perfusion assessment, intraoperative visualization of the ureter, and tumor localization. It is particularly valuable in evaluating anastomotic leaks and aiding in precise tumor resection during minimally invasive surgeries. Studies have shown mixed results on its effectiveness in reducing anastomotic leak rates, highlighting the need for further research. In thoracic surgery, ICG facilitates the identification and resection of pulmonary bullae, as well as the precise localization of pulmonary nodules during video-assisted surgery. In urology, ICG aids in localizing renal tumors and guiding selective arterial occlusion during partial nephrectomy. Its role in identifying the lymphatic pathway in prostate cancer and sentinel lymph node biopsy in gynecological cancer is also discussed. Despite its benefits, the use of ICG fluorescence faces challenges such as limited tissue penetration, the potential for false results, a lack of standardized protocols, and high equipment costs. Nonetheless, it remains a powerful tool that could improve surgical outcomes.

Detection and dissection of sentinel nodes in endometrial endometrioid cancer with indocyanine green using PinPoint laparoscopy: Analysis of the learning curve

OBJECTIVE

Early-stage endometrial endometrioid adenocarcinoma is managed through laparoscopic total hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy. Detection of positive nodes is rare, and lymphadenectomy may involve complications. Pelvic sentinel lymph node dissection can prevent complete dissection. Herein, we evaluated the learning curve of sentinel lymph node dissection using indocyanine green.

STUDY DESIGN

All surgeries for endometrial endometrioid adenocarcinoma were performed laparoscopically with indocyanine green to detect sentinel nodes. The primary outcome was the ability to identify and resect sentinel lymph nodes on each side. The secondary outcome was correspondence between the frozen section histology of the nodes with the final histology.

RESULTS

Among 31 patients with endometrial endometrioid adenocarcinoma treated between October 2018 and August 2020, 29 who underwent laparoscopy using indocyanine green were enrolled. Complete lymphadenectomy was performed in 16 patients. Failure to recognize sentinel nodes on right and left sides occurred in 10.34% and 0% of cases, respectively. The median number of recognized and dissected sentinel nodes was 1 on both sides (range 0-5). One patient had a lymph node positive for malignancy on histology (3.45%) on both sides. There were 13 and 14 cases of negative frozen sections on the right and left sides, respectively, and 1 case of a positive frozen section with positive whole pelvic lymph nodes.

CONCLUSION

Sentinel node dissection using indocyanine green in endometrial endometrioid adenocarcinoma has a distinct learning curve; however, it is practical and achievable for skilled surgeons.

Validation of Sentinel Lymph Node Biopsy in Robotic Endometrial Cancer Staging Surgery: Results From a High-Volume Center in India

PURPOSE

Lymph node involvement is one of the most important factors influencing recurrence and survival in patients with endometrial cancer (EC). However, the therapeutic role of lymphadenectomy in early-stage disease has been called into question. Sentinel lymph node (SLN) mapping may be an acceptable alternative to omitting lymphadenectomy or performing a complete lymphadenectomy in patients with EC.

To validate SLN biopsy (SLNB) using indocyanine green (ICG) dye and near-infrared imaging in the background of comprehensive lymphadenectomy in patients with EC undergoing robotic staging surgery at Tata Medical Center.

METHODS

This was a single-center, prospective observational study involving patients with EC undergoing robotic staging. Patients received a standardized cervical injection of ICG at the 3- and 9-o'clock positions, with the dye reinjected if mapping failed. Depending on preoperative histology and radiological staging, patients had SLNB or comprehensive systematic lymphadenectomy in addition to SLNB.

RESULTS

The study included 105 female patients, of whom 71 underwent SLN and full lymphadenectomy and 34 underwent only SLN. There was bilateral mapping in 92 (87.61%) patients, with no mapping in one patient. In 18 patients, ICG dye was reinjected. With the exception of one, the rest had successful mapping after reinjection. The sensitivity of the SLN-ICG algorithm was 92.3%, and the negative predictive value was 98.3%. Ultrastaging necessitated upstaging in 8.57% of patients.

CONCLUSION

With a very high negative predictive value, SLN mapping with ICG dye has a high degree of diagnostic accuracy in detecting lymph node metastases in EC.

Quantifying the Impact of Signal-to-background Ratios on Surgical Discrimination of Fluorescent Lesions

PURPOSE

Surgical fluorescence guidance has gained popularity in various settings, e.g., minimally invasive robot-assisted laparoscopic surgery. In pursuit of novel receptor-targeted tracers, the field of fluorescence-guided surgery is currently moving toward increasingly lower signal intensities. This highlights the importance of understanding the impact of low fluorescence intensities on clinical decision making. This study uses kinematics to investigate the impact of signal-to-background ratios (SBR) on surgical performance.

METHODS

Using a custom grid exercise containing hidden fluorescent targets, a da Vinci Xi robot with Firefly fluorescence endoscope and ProGrasp and Maryland forceps instruments, we studied how the participants' (N = 16) actions were influenced by the fluorescent SBR. To monitor the surgeon's actions, the surgical instrument tip was tracked using a custom video-based tracking framework. The digitized instrument tracks were then subjected to multi-parametric kinematic analysis, allowing for the isolation of various metrics (e.g., velocity, jerkiness, tortuosity). These were incorporated in scores for dexterity (Dx), decision making (DM), overall performance (PS) and proficiency. All were related to the SBR values.

RESULTS

Multi-parametric analysis showed that task completion time, time spent in fluorescence-imaging mode and total pathlength are metrics that are directly related to the SBR. Below SBR 1.5, these values substantially increased, and handling errors became more frequent. The difference in Dx and DM between the targets that gave SBR < 1.50 and SBR > 1.50, indicates that the latter group generally yields a 2.5-fold higher Dx value and a threefold higher DM value. As these values provide the basis for the PS score, proficiency could only be achieved at SBR > 1.55.

CONCLUSION

By tracking the surgical instruments we were able to, for the first time, quantitatively and objectively assess how the instrument positioning is impacted by fluorescent SBR. Our findings suggest that in ideal situations a minimum SBR of 1.5 is required to discriminate fluorescent lesions, a substantially lower value than the SBR 2 often reported in literature.

Fluorescent Indocyanine Green versus Technetium-99m and Blue Dye for Bilateral SENTinel Lymph Node Detection in Stage I-IIA Cervical Cancer (FluoreSENT): protocol for a non-inferiority study

INTRODUCTION

Nowadays, two predominant methods for detecting sentinel lymph nodes (SLNs) in cervical cancer are in use. The most conventional method is a combination of a radiotracer, technetium-99m (^99mTc) and blue dye. More recently, another method for SLN mapping using indocyanine green (ICG) is becoming widely accepted. ICG is a fluorescent dye, visualised intraoperatively with near-infrared (NIR) fluorescence imaging, providing real-time visual navigation. The presumed advantages of ICG over ^99mTc, that is, being cheaper, non-radioactive and logistically more attractive, are only valuable if its detection rate proves to be at least non-inferior. Before omitting the well-functioning and evidence-based combined approach of ^99mTc and blue dye, we aim to provide prospective evidence on the non-inferiority of ICG with NIR fluorescence imaging.

METHODS AND ANALYSIS

We initiated a prospective non-inferiority study with a paired comparison of both SLN methods in a single sample of 101 patients with International Federation of Gynecology and Obstetrics (FIGO) stage IA-IB2 or IIA1 cervical cancer receiving primary surgical treatment. All patients undergo SLN mapping with ICG and NIR fluorescence imaging in adjunct to mapping with ^99mTc (including single photon emission computed tomography with X-ray computed tomography (SPECT/CT)) and blue dye. Surgeons start SLN detection with ICG while being blinded for the preoperative outcome of SPECT/CT to avoid biased detection with ICG. Primary endpoint of this study is bilateral SLN detection rate of both methods (ie, detection of at least one SLN in each hemipelvis). Since we compare strategies for SLN mapping that are already applied in current daily practice for different types of cancer, no additional risks or burdens are expected from these study procedures.

ETHICS AND DISSEMINATION

The current study is approved by the Medical Ethics Research Committee Utrecht (reference number 21-014). Findings arising from this study will be disseminated in peer-reviewed journals, academic conferences and through patient organisations.

TRIAL REGISTRATION NUMBER

NL9011 and EudraCT 2020-005134-15.

Fluorescence-guided radical prostatectomy

Robotic-assisted laparoscopic radical prostatectomy represents one of the most common operations in urologic oncology and involves several critical technical steps including pelvic lymph node dissection, cavernous nerve sparing and vesicourethral anastomosis. The quality of performing these steps is linked to functional and oncological outcomes. Indocyanine green [ICG] is a non-radioactive, water-soluble compound which allows for enhanced visualization with near-infrared fluorescence of both anatomical structures and vasculature during complex abdominal operations such as prostatectomy. During the last decade, several investigators have examined the value and role of ICG fluorescence during prostatectomy. In this review, we sought to evaluate the body of evidence for fluorescence-guided robotic prostatectomy as well as assess potential future areas of investigation with this technology.

Robotic Staging of Cervical Cancer With Simultaneous Detection of Primary Pelvic and Secondary Para-Aortic Sentinel Lymph Nodes: Reproducibility in a First Case Series

Objective

Discrepancies exist among international guidelines on the surgical staging of para-aortic lymph nodes in locally advanced cervical cancer (LACC), varying from considering a para-aortic lymph node dissection, at least up to the inferior mesenteric artery, to a complete para-aortic lymph node dissection. In this study, we aim to assess the reproducibility of our recently reported robotic technique using indocyanine green for identifying besides primary pelvic sentinel lymph nodes (SLNs), secondary para-aortic SLNs in a first case-cohort of cervical cancer patients.

Methods

A retrospective case series of LACC patients with/without suspicious pelvic lymph nodes (LNs) on imaging (including two patients with an additional suspicious para-aortic LN) is reported. All patients underwent a robotic pelvic SLN and para-aortic sentinel/nonsentinel LN dissection using the da Vinci Xi platform. Indocyanine green was used as a fluorescent tracer, at a concentration of 1.9 mg/mL, and injected as 0.5 mL in each quadrant of the cervix.

Results

In a total of 10 cases, primary pelvic SLNs (90% bilateral) with subsequent secondary para-aortic SLNs were identified in all cases. Lower para-aortic SLNs were present in all cases, and upper para-aortic SLNs were found in 9 out of 10 cases. The mean age of the cervical cancer patients was 49.8 years (SD ± 6.89), and the mean body mass index (BMI; kg/m²) was 23.96 (SD ± 4.60). The median total operative time was 105.5 min (range: 89–141 min). The mean numbers of primary pelvic SLNs and secondary lower and upper para-aortic SLNs were 3.10 (SD ± 1.10), 2.90 (SD ± 0.74), and 2.30 (SD ± 1.57), respectively. The median number of total para-aortic LNs (PALNs) dissected per patient was 11.5. Six patients had positive primary pelvic SLNs, and two had secondary positive para-aortic SLNs. The nonsentinel para-aortic LNs were negative in all cases. There were no intra- or postoperative complications.

Conclusion

Our preliminary experience demonstrates the reproducibility of identifying, besides primary pelvic SLNs, secondary lower and upper para-aortic SLNs during robotic staging in LACC. A surgical approach limiting a complete para-aortic LN dissection could reduce the potential risks and morbidity associated with this procedure. To determine the sensitivity and negative predictive value of this new surgical approach, and whether the lower para-aortic SLNs under the inferior mesenteric artery are representative of the whole para-aortic region, large prospective observational studies are needed in LACC and/or those with suspicious pelvic LNs but apparent normal para-aortic LNs on imaging.

Indocyanine green-guided sentinel lymph node mapping during laparoscopic surgery with vaginal cuff closure but no uterine manipulator for cervical cancer

BACKGROUND

Lymph node metastasis is a critical prognostic factor in cervical cancer. Considering the potential complications of lymphadenectomy and desirability of avoiding systemic lymphadenectomy, accurate intraoperative prediction of the existence of lymph node metastasis is important in patients undergoing surgery for cervical cancer. We evaluated the feasibility and value of indocyanine green (ICG) use for sentinel lymph node (SLN) mapping during laparoscopic surgery performed for cervical cancer.

METHODS

This single-center cohort study included 77 patients undergoing a new laparoscopic radical surgery method with pelvic lymphadenectomy for early-stage cervical cancer. The surgery, performed without using a uterine manipulator, included creation of a vaginal cuff. Bilateral ICG-guided SLN mapping and rapid histopathological examination were performed, and results were analyzed in relation to final histopathologic diagnoses.

RESULTS

The SLN pelvic side-specific detection rate was 93.5%, sensitivity (SLN-positive cases/SLN-detected pelvic lymph node-positive cases) was 100%, intraoperative negative predictive value (NPV) was 97.8%, and final pathological NPV was 100%. The detection rate was significantly lower for tumors ≥ 2 cm in diameter than for tumors < 2 cm in diameter. Micrometastases were missed by intraoperative examination in 3 cases.

CONCLUSION

The high NPV suggests the feasibility and usefulness of ICG-based SLN mapping plus rapid intraoperative examination for identification of metastatic SLNs. Use of ICG-based mapping for intraoperative identification of SLNs in patients undergoing this new laparoscopic surgery method for early-stage cervical cancer was particularly effective for tumors < 2 cm in diameter. However, incorporating a search for micrometastases into rapid intraoperative histopathologic examination may be necessary.

Sentinel lymph node biopsy at robotic-assisted hysterectomy for atypical hyperplasia and endometrial cancer

Lymph node (LN) evaluation in endometrial cancer is controversial. Sentinel lymph node biopsy (SLNB) allows for an accurate nodal assessment while minimising the risks of a full pelvic lymph node dissection (PLND). The aims of this study are to examine the characteristics and peri-operative outcomes of women with atypical hyperplasia (AH) or endometrial cancer undergoing robotic-assisted hysterectomy (RAH) ± SLNB or PLND; to examine the utilisation, feasibility and role of SLNB and compare their peri-operative outcomes. Retrospective cohort study from December 2018 to February 2021 of women who underwent RAH ± LN assessment for endometrial cancer or AH. 115 women underwent RAH. 59% had SLNB, 29% had no LN assessment, and 12% had PLND. The final diagnosis was mostly early stage low-grade disease; Stage 1A-50%, Grade 1 endometrioid adenocarcinoma (EAC)-56%. The detection rate was 90%. There was a statistically significant trend towards performing SLNB over time (P value 0.004). There was a statistically shorter length of stay, less estimated blood loss, and shorter surgical duration in the SLNB cohort, compared to the no LN assessment cohort (P values 0.02, 0.01, and 0.03, respectively). There was statistically significant less estimated blood loss and surgical duration in the SLNB compared to the PLND cohort (P values 0.03 and 0.001, respectively). SLNB at RAH was utilised and feasible. It was safe with a low complication rate and had advantages compared to PLND cohort. SLNB should be considered in suitable selected women undergoing surgery for endometrial cancer or AH.

Synergistic strategy of rare-earth doped nanoparticles for NIR-II biomedical imaging

Featuring simultaneous multicolor imaging for multiple targets, a synergistic strategy has become promising for fluorescence imaging applications. Visible and first near infrared (NIR-I, 700-900 nm) fluorophores have been explored for multicolor imaging to achieve good multi-target capacity, but they are largely hampered by the narrow imaging bands available (400-900 nm, bandwidth 500 nm), the broad emission spectra of many fluorophores, shallow tissue penetration and scattering loss. With attractive characteristic emission peaks in the second NIR window (NIR-II, 1000-1700 nm), a narrow emission spectrum, and deeper tissue penetration capability, rare-earth doped nanoparticles (RENPs) have been considered by us to be outstanding candidates for multicolor bioimaging. Herein, two RENPs, NaYF4:Yb20Er2@NaYF4 and NaYF4:Nd5@NaYF4, were prepared and modified with polyethylene glycol (PEG) to explore simultaneous imaging in the NIR-IIb (1530 nm, under 980 nm laser excitation) and the NIR-II (1060 nm, under 808 nm laser excitation) windows. The PEGylated-RENPs (RENPs@PEG) were able to simultaneously visualize the circulatory system, trace the lymphatic system, and evaluate the skeletal system. Our study demonstrates that RENPs have high synergistic imaging capability in multifunctional biomedical applications using their NIR-II fluorescence. Importantly, the two RENPs@PEG are complementary to each other for higher temporal resolution in NaYF4:Nd5@NaYF4@PEG and higher spatial resolution in NaYF4:Yb20Er2@NaYF4@PEG, which may provide more comprehensive and accurate imaging diagnosis. In conclusion, RENPs are highly promising nanomaterials for multicolor imaging in the NIR-II window.

Comparison of radio-isotope method with 99m technetium and near-infrared fluorescent imaging with indocyanine green for sentinel lymph node detection in endometrial cancer

BACKGROUND

We aimed to compare the detection rate of pelvic sentinel lymph node between the radio-isotope with 99m technetium (99mTc)-labeled phytate and near-infrared fluorescent imaging with indocyanine green in patients with endometrial cancer.

METHODS

This study included 122 patients who had undergone sentinel lymph node mapping using 99mTc and indocyanine green. In the radio-isotope method, sentinel lymph nodes were detected using uterine cervix 99mTc injections the day before surgery. Following injection, the number and locations of the sentinel lymph nodes were evaluated by lymphoscintigraphy. In addition, indocyanine green was injected into the cervix immediately before surgery.

RESULTS

The overall pelvic sentinel lymph node detection rate (at least one pelvic sentinel lymph node detected) was not significantly different between 99mTc (95.9% [117/122]) and indocyanine green (94.3% [115/122]). Similarly, the bilateral sentinel lymph node detection rate was not significantly different between 99mTc (87.7% [107/122]) and indocyanine green (79.5% [97/122]). More than two sentinel lymph nodes per unilateral pelvic lymph node were found in 12.3% (15/122) and 27% (33/122) of cases with 99mTc and indocyanine green, respectively, in the right pelvic side, and 11.5% (14/122) and 32.8% (40/122) of cases with 99mTc and indocyanine green, respectively, in the left pelvic side. indocyanine green showed that there were significantly more than two sentinel lymph nodes in either the left or right pelvic sentinel lymph nodes (P < 0.0001). There was a significant difference in the mean number of total pelvic sentinel lymph nodes between 99mTc (2.2) and indocyanine green (2.5) (P = 0.028) methods.

CONCLUSION

Although indocyanine green is useful for sentinel lymph node identification, we believe it is better to use it in combination with 99mTc until the surgeon is accustomed to it.

Comprehensive Review of Fluorescence Applications in Gynecology

Since the introduction of indocyanine green (ICG) as a fluorophore in near-infrared imaging, fluorescence visualization has become an essential tool in many fields of surgery. In the field of gynecology, recent new applications have been proposed and found their place in clinical practice. Different applications in gynecology were investigated, subcategorized, and overviewed concerning surgical applications and available dyes. Specific applications in which fluorescence-guided surgery was implemented in gynecology are described in this manuscript—namely, sentinel node biopsy, mesometrium visualization, angiography of different organs, safety issues in pregnant women, ureters visualization, detection of peritoneal metastases, targeted fluorophores for cancer detection, fluorescent contamination hysterectomy, lymphography for lower limb lymphedema prevention, tumor margin detection, endometriosis, and metastases mapping. With evolving technology, further innovative research on the new applications of fluorescence visualization in cancer surgery may help to establish these techniques as standards of high-quality surgery in gynecology. However, more investigations are necessary in order to assess if these innovative tools can also be effective to improve patient outcomes and quality of life in different gynecologic malignancies.

A narrative review of fluorescence imaging in robotic-assisted surgery

Objective

In this review, we provide examples of applications of fluorescence imaging in urologic, gynecologic, general, and endocrine surgeries.

Background

While robotic-assisted surgery has helped increase the availability of minimally invasive procedures across surgical specialties, there remains an opportunity to reduce adverse events associated with open, laparoscopic, and robotic-assisted methods. In 2011, fluorescence imaging was introduced as an option to the da Vinci Surgical System, and has been standard equipment since 2014. Without interfering with surgical workflow, this fluorescence technology named Firefly^® allows for acquisition and display of near-infrared fluorescent signals that are co-registered with white light endoscopic images. As a result, robotic surgeons of all specialties have been able to explore the clinical utility of fluorescence guided surgery.

Methods

Literature searches were performed using the PubMed and MEDLINE databases using the keywords "robotic-assisted fluorescence surgery", "ICG robotic surgery", and "fluorescence guided surgery" covering the years 2011-2020.

Conclusions

Real-time intraoperative fluorescence guidance has shown great potential in helping guide surgeons in both simple and complex surgical interventions. Indocyanine green is one of the most widely-used imaging agents in fluorescence guided surgery, and other targeted, near-infrared imaging agents are in various stages of development. Fluorescence is becoming a reliable tool that can help surgeons in their decision-making process in some specialties, while explorations continue in others.

Association between the donor to recipient ICG-PDR variation rate and the functional recovery of the graft after orthotopic liver transplantation: A case series

Background

Despite current advances in liver transplant surgery, post-operative early allograft dysfunction still complicates the patient prognosis and graft survival. The transition from the donor has not been yet fully understood, and no study quantifies if and how the liver function changes through its transfer to the recipient. The indocyanine green dye plasma disappearance rate (ICG-PDR) is a simple validated tool of liver function assessment. The variation rate between the donor and recipient ICG-PDR still needs to be investigated.

Materials and methods

Single-center retrospective study. ICG-PDR determinations were performed before graft retrieval (T1) and 24 hours after transplant (T2). The ICG-PDR relative variation rate between T1 and T2 was calculated to assess the graft function and suffering/recovering. Matched data were compared with the MEAF model of graft dysfunction.

Objective

To investigate whether the variation rate between the donor ICG-PDR value and the recipient ICG-PDR measurement on first postoperative day (POD₁) can be associated with the MEAF score.

Results

36 ICG-PDR measurements between 18 donors and 18 graft recipients were performed. The mean donor ICG-PDR was 22.64 (SD 6.35), and the mean receiver’s ICG-PDR on 1st POD was 17.68 (SD 6.60), with a mean MEAF value of 4.51 (SD 1.23). Pearson’s test stressed a good, linear inverse correlation between the ICG-PDR relative variation and the MEAF values, correlation coefficient -0.580 (p = 0.012).

Conclusion

The direct correlation between the donor to recipient ICG-PDR variation rate and MEAF was found. Measurements at T1 and T2 showed an up- or downtrend of the graft performance that reflect the MEAF values.

The Advantage of Pinpoint Camera System With Indocyanine Green for Sentinel Lymph Node Micrometastasis Detection in Low Risk Endometrial Cancer

BACKGROUND/AIM

This report outlines our experience in the management of 10 cases of low-risk endometrial cancer with Indocyanine Green for sentinel lymph node (SLN) mapping using the Pinpoint 30-degree 4K S1 SPY real-time camera system (Stryker). This system offers simultaneous, real-time, high-definition white light and fluorescence imaging through a single laparoscope, without the need to change camera filters.

PATIENTS AND METHODS

In our retrospective case series we included all endometrioid endometrial cancers of grade G1 and pre-operative radiological staging FIGO 1A reported on magnetic resonance imaging (MRI) that were treated laparoscopically from October 2019 to April 2020.

RESULTS

Bilateral sentinel lymph node excision was achieved in 9 out of 10 cases. In one patient, one sentinel lymph node featuring a micrometastasis of <2 mm was identified.

CONCLUSION

A specialist minimal access team can safely and reliably reproduce this technique for sentinel lymph node excision.

Sentinel node biopsy for diagnosis of lymph node involvement in endometrial cancer

BACKGROUND

Pelvic lymphadenectomy provides prognostic information for those diagnosed with endometrial (womb) cancer and provides information that may influence decisions regarding adjuvant treatment. However, studies have not shown a therapeutic benefit, and lymphadenectomy causes significant morbidity. The technique of sentinel lymph node biopsy (SLNB), allows the first draining node from a cancer to be identified and examined histologically for involvement with cancer cells. SLNB is commonly used in other cancers, including breast and vulval cancer. Different tracers, including colloid labelled with radioactive technetium-99, blue dyes, e.g. patent or methylene blue, and near infra-red fluorescent dyes, e.g. indocyanine green (ICG), have been used singly or in combination for detection of sentinel lymph nodes (SLN).

OBJECTIVES

To assess the diagnostic accuracy of sentinel lymph node biopsy (SLNB) in the identification of pelvic lymph node involvement in women with endometrial cancer, presumed to be at an early stage prior to surgery, including consideration of the detection rate.

SEARCH METHODS

We searched MEDLINE (1946 to July 2019), Embase (1974 to July 2019) and the relevant Cochrane trial registers.

SELECTION CRITERIA

We included studies that evaluated the diagnostic accuracy of tracers for SLN assessment (involving the identification of a SLN plus histological examination) against a reference standard of histological examination of removed pelvic +/- para-aortic lymph nodes following systematic pelvic +/- para-aortic lymphadenectomy (PLND/PPALND) in women with endometrial cancer, where there were sufficient data for the construction of two-by-two tables.

DATA COLLECTION AND ANALYSIS

Two review authors (a combination of HN, JM, NW, RG, and WH) independently screened titles and abstracts for relevance, classified studies for inclusion/exclusion and extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We calculated the detection rate as the arithmetic mean of the total number of SLNs detected out of the total number of women included in the included studies with the woman as the unit of analysis, used univariate meta-analytical methods to estimate pooled sensitivity estimates, and summarised the results using GRADE.

MAIN RESULTS

The search revealed 6259 unique records after removal of duplicates. After screening 232 studies in full text, we found 73 potentially includable records (for 52 studies), although we were only able to extract 2x2 table data for 33 studies, including 2237 women (46 records) for inclusion in the review, despite writing to trial authors for additional information. We found 11 studies that analysed results for blue dye alone, four studies for technetium-99m alone, 12 studies that used a combination of blue dye and technetium-99m, nine studies that used indocyanine green (ICG) and near infra-red immunofluorescence, and one study that used a combination of ICG and technetium-99m. Overall, the methodological reporting in most of the studies was poor, which resulted in a very large proportion of 'unclear risk of bias' ratings. Overall, the mean SLN detection rate was 86.9% (95% CI 82.9% to 90.8%; 2237 women; 33 studies; moderate-certainty evidence). In studies that reported bilateral detection the mean rate was 65.4% (95% CI 57.8% to 73.0%) . When considered according to which tracer was used, the SLN detection rate ranged from 77.8% (95% CI 70.0% to 85.6%) for blue dye alone (559 women; 11 studies; low-certainty evidence) to 100% for ICG and technetium-99m (32 women; 1 study; very low-certainty evidence). The rates of positive lymph nodes ranged from 5.2% to 34.4% with a mean of 20.1% (95% CI 17.7% to 22.3%). The pooled sensitivity of SLNB was 91.8% (95% CI 86.5% to 95.1%; total 2237 women, of whom 409 had SLN involvement; moderate-certainty evidence). The sensitivity for of SLNB for the different tracers were: blue dye alone 95.2% (95% CI 77.2% to 99.2%; 559 women; 11 studies; low-certainty evidence); Technetium-99m alone 90.5% (95% CI 67.7% to 97.7%; 257 women; 4 studies; low-certainty evidence); technetium-99m and blue dye 91.9% (95% CI 74.4% to 97.8%; 548 women; 12 studies; low-certainty evidence); ICG alone 92.5% (95% CI 81.8% to 97.1%; 953 women; 9 studies; moderate-certainty evidence); ICG and blue dye 90.5% (95% CI 63.2.6% to 98.1%; 215 women; 2 studies; low-certainty evidence); and ICG and technetium-99m 100% (95% CI 63% to 100%; 32 women; 1 study; very low-certainty evidence). Meta-regression analyses found that the sensitivities did not differ between the different tracers used, between studies with a majority of women with FIGO stage 1A versus 1B or above; between studies assessing the pelvic lymph node basin alone versus the pelvic and para-aortic lymph node basin; or between studies that used subserosal alone versus subserosal and cervical injection. It should be noted that a false-positive result cannot occur, as the histological examination of the SLN is unchanged by the results from any additional nodes removed at systematic lymphadenectomy.

AUTHORS' CONCLUSIONS

The diagnostic test accuracy for SLNB using either ICG alone or a combination of a dye (blue or ICG) and technetium-99m is probably good, with high sensitivity, where a SLN could be detected. Detection rates with ICG or a combination of dye (ICG or blue) and technetium-99m may be higher. The value of a SLNB approach in a treatment pathway, over adjuvant treatment decisions based on uterine factors and molecular profiling, requires examination in a high-quality intervention study.

Indocyanine green versus technetium-99m with blue dye for sentinel lymph node detection in early-stage cervical cancer: A systematic review and meta-analysis

Background

The fluorescent dye indocyanine green (ICG) has emerged as a promising tracer for intraoperative detection of sentinel lymph nodes (SLNs) in early‐stage cervical cancer. Although researchers suggest the SLN detection of ICG is equal to the more conventional combined approach of a radiotracer and blue dye, no consensus has been reached.

Aims

We aimed to assess the differences in overall and bilateral SLN detection rates with ICG versus the combined approach, the radiotracer technetium‐99m (^99mTc) with blue dye.

Methods and Results

We searched MEDLINE, Embase, and the Cochrane Library from inception to January 1, 2020 and included studies reporting on a comparison of SLN detection with ICG versus ^99mTc with blue dye in early‐stage cervical cancer. The overall and bilateral detection rates were pooled with random‐effects meta‐analyses.

From 118 studies retrieved seven studies (one cross‐sectional; six retrospective cohorts) were included, encompassing 589 patients. No significant differences were found in the pooled overall SLN detection rate of ICG versus ^99mTc with blue dye. Meta‐analyses of all studies showed ICG to result in a higher bilateral SLN detection rate than ^99mTc with blue dye; 90.3% (95%CI, 79.8‐100.0%) with ICG versus 73.5% (95%CI, 66.4‐80.6%) with 99mTc with blue dye. This resulted in a significant and clinically relevant risk difference of 16.6% (95%CI, 5.3‐28.0%). With sensitivity analysis, the risk difference of the bilateral detection rate maintained in favor of ICG but was no longer significant (13.2%, 95%CI −0.8‐27.3%).

Conclusion

ICG appears to provide higher bilateral SLN detection rates compared to ^99mTc with blue dye in patients with early‐stage cervical cancer. However, in adherence with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) guidelines, the quality of evidence is too low to provide strong recommendations and directly omit the combined approach of ^99mTc with blue dye.

Lymph node evaluation in endometrial cancer: how did it change over the last two decades?

Endometrial cancer (EC) is the most common gynecological malignancy in developed countries, and surgery represents the pivotal part of treatment. Hysterectomy and salpingo-oophorectomy allow removing the primary tumor and defining patients at higher risk, who might benefit from adjuvant therapies. Minimally invasive surgery is associated with superior postoperative outcomes and represents a safe and effective approach for surgical staging of EC. The lymph node status evaluation in EC is still a matter of debate. Over the last twenty years much has changed, moving from a full systematic pelvic and paraaortic lymphadenectomy for staging purpose to the removal of the pelvic (with or without paraaortic) lymph nodes only in selected EC classes of risk. Two randomized trials failed to demonstrate survival benefits of lymphadenectomy in case of apparent early stage EC; however, its prognostic role has never been questioned. At present, with the aim of reducing the surgical-related morbidity, sentinel node mapping is emerging as a safe and valid alternative to lymphadenectomy for EC staging, demonstrating high accuracy and an increased detection of lymph nodes metastasis. Here, we performed a review of the most significant studies, which supported the changes in the lymph node status evaluation for EC over the last two decades.

A Feasibility Study of Sentinel Lymph Node Biopsy in Endometrial Cancer Using Technetium 99m Nanocolloid

To study the feasibility of sentinel node biopsy in early-stage endometrial cancer and to analyse the detection rate of sentinel lymph node (SLN) using preoperative cervical injection of Tc99m nanocolloid. Thirty-five patients with preoperative histological diagnosis of endometrial cancer without any extrauterine involvement on imaging were included in the study. Sentinel node mapping was done by cervical injection of Tc99m nanocolloid on the evening before surgery. Scintigraphic images were taken using gamma camera. Intraoperatively, nodes showing radioactivity were detected using hand-held gamma probe, dissected out separately and labelled as sentinel lymph nodes. Detection rate was calculated and analysed with respect to various parameters. Sentinel lymph node biopsy (SLNB) is feasible in endometrial cancer using cervical injection of Tc99m nanocolloid. SLN detection was done in 33 (94.3%) out of 35 patients. Bilateral detection was feasible in 19 patients (54.3%) with detection in left and right hemipelvis being 74.3%. Detection rate of SLN was 93.7% in endometrioid adenocarcinoma. Sentinel node was detected in all the patients with non-endometrioid histology. The SLNB using cervical injection of Tc99m nanocolloid is feasible in endometrial cancer. It is a safe and easily reproducible technique with good detection rate and high sensitivity. Stage of the tumour, grade and myometrial invasion do not seem to have an influence on sentinel node detection. Cervical involvement, enlarged lymph nodes and obstructed lymphatics can affect sentinel node mapping adversely.

Diagnostic Accuracy and Clinical Impact of Sentinel Lymph Node Sampling in Endometrial Cancer at High Risk of Recurrence: A Meta-Analysis

Purpose. To assess the value of sentinel lymph node (SLN) sampling in high risk endometrial cancer according to the ESMO-ESGO-ESTRO classification. Methods. We performed a comprehensive search on PubMed for clinical trials evaluating SLN sampling in patients with high risk endometrial cancer: stage I endometrioid, grade 3, with at least 50% myometrial invasion, regardless of lymphovascular space invasion status; or stage II; or node-negative stage III endometrioid, no residual disease; or non-endometrioid (serous or clear cell or undifferentiated carcinoma, or carcinosarcoma). All patients underwent SLN sampling followed by pelvic with or without para-aortic lymphadenectomy. Results. We included 17 original studies concerning 1322 women. Mean detection rates were 89% for unilateral and 68% for bilateral. Pooled sensitivity was 88.5% (95%CI: 81.2–93.2%), negative predictive value was 96.0% (95%CI: 93.1–97.7%), and false negative rate was 11.5% (95%CI: 6.8; 18.8%). We noted heterogeneity in SLN techniques between studies, concerning the tracer and its detection, the injection site, the number of injections, and the surgical approach. Finally, we found a correlation between the number of patients included and the SLN sampling performances. Discussion. This meta-analysis estimated the SLN sampling performances in high risk endometrial cancer patients. Data from the literature show the feasibility, the safety, the limits, and the impact on surgical de-escalation of this technique. In conclusion, our study supports the hypothesis that SLN sampling could be a valuable technique to diagnose lymph node involvement for patients with high risk endometrial cancer in replacement of conventional lymphadenectomy. Consequently, randomized clinical trials are necessary to confirm this hypothesis.

Utility of Intraoperative Fluorescence Imaging in Gynecologic Surgery: Systematic Review and Consensus Statement

BACKGROUND

This study aimed to review the current knowledge on the utility of intraoperative fluorescence imaging in gynecologic surgery and to give evidence-based recommendations to improve the quality of care for women who undergo gynecologic surgery.

METHODS

A computer-based systematic review of the MEDLINE, CENTRAL, Pubmed, EMBASE, and SciSearch databases as well as institutional guidelines was performed. The time limit was set at 2000-2019. For the literature search, PRISMA guidelines were followed. A modified-Delphi method was performed in three rounds by a panel of experts to reach a consensus of conclusions and recommendations.

RESULTS

Indocyanine green (ICG) is used primarily in gynecology for sentinel node-mapping. In endometrial and cervical cancer, ICG is a feasible, safe, time-efficient, and reliable method for lymphatic mapping, with better bilateral detection rates. Experience in vulvar cancer is more limited, with ICG used together with Tc-99 m as a dual tracer and alone in video endoscopic inguinal lymphadenectomy. In early ovarian cancer, results are still preliminary but promising. Indocyanine green fluorescence imaging also is used for ureteral assessment, allowing intraoperative ureteral visualization, to reduce the risk of ureteral injury during gynecologic surgery.

CONCLUSIONS

For most gynecologic cancers, ICG fluorescence imaging is considered the tracer of choice for lymphatic mapping. The use of this new technology expands to a better ureteral assessment.

British Gynaecological Cancer Society (BGCS) cervical cancer guidelines: Recommendations for practice

Cervix cancer in many countries is declining and screening programmes and immunisation will reduce the incidence in the next few decades. This guideline attempts to cover management of invasive disease reflecting diagnosis and imaging including new imaging and sentinel lymph node biopsies. Smaller volume disease is usually managed surgically whereas advanced disease is treated with (chemo)- radiation. It also includes discussion of fertility sparing procedures. Practices are changing frequently for all aspects of care usually in attempts to reduce complications and improve quality of life. The management of advanced disease is treated by chemotherapy and the use of newer agents is also discussed. Other sections discuss specialist situations such as cancer in pregnancy, rare cervical tumours, late effects and supportive measures and fertility preserving approaches.

The role of sentinel lymph node mapping in endometrial carcinoma

Endometrial cancer is the most commonly diagnosed gynecological malignancy in developing countries, and the second malignancy after cervical cancer in developing countries. The primary treatment is based on surgical and pathologic staging including extrafascial type A radical hysterectomy bilateral salpingo-oophorectomy and pelvic and latero-aortic lymphadenectomy. Minimally invasive surgery is the most widely used technique. Sentinel node biopsy is part of this concept and has reached the management of endometrial cancer. The aim of this review was to describe the history, the different injection techniques and results of sentinel node biopsy, and analyze the future role of this technique in endometrial carcinoma.

Systemic Sentinel Lymph Node Detection Using Fluorescence Imaging After Indocyanine Green Intravenous Injection in Colorectal Cancer: Protocol for a Feasibility Study

Background

Nodal staging is a major concern in colorectal cancer as it is an important prognostic factor. Several techniques that could potentially improve patient treatment and prognosis have been developed to increase the accuracy of nodal staging. Sentinel lymph node detection has been shown to accurately reflect nodal status in various tumors and has become the standard procedure in nodal staging of breast cancer and melanoma. However, in colorectal cancer, sentinel lymph node detection techniques are still controversial as the sensitivity reported in the literature varies from one study to another. Recently, indocyanine green fluorescence–guided surgery has been reported to be a useful technique for detection of macroscopic and microscopic metastatic deposits in lymph nodes after intravenous administration of indocyanine green dye. However, no studies have focused on the potential role of sentinel lymph node detection after systemic administration of indocyanine green dye, so-called systemic sentinel lymph nodes, or on the correspondence between the identification of the sentinel lymph node by standard local injection techniques and the detection of fluorescent lymph nodes with this new approach.

Objective

The aim of this protocol is to validate the concept of sentinel lymph nodes identified by fluorescence imaging after intravenous injection of indocyanine green dye and to compare the sentinel lymph nodes identified by fluorescence imaging with sentinel lymph nodes detected by the standard blue dye technique.

Methods

This study (SeLyNoFI; Sentinel Lymph Nodes Fluorescence Imaging) is a diagnostic, single-arm, open-label feasibility study, including patients with colorectal adenocarcinoma with or without metastatic disease who are admitted for elective colorectal resection of the primary tumor. This study evaluates the feasibility of a new approach for improving the accuracy of nodal staging using fluorescence imaging after intravenous administration of indocyanine green dye. Sensitivity, positive predictive value, and accuracy of the classical blue dye technique and of the investigatory fluorescence imaging technique will be calculated. Translational research will be proposed, if applicable.

Results

As of June 2020, this study has been registered. Submission for ethical review is planned for September 2020.

Conclusions

The potential correlation between the two different approaches to detect sentinel lymph nodes offers new strategies for improving the accuracy of nodal staging in colorectal cancer. This new concept of the systemic sentinel lymph node and a greater understanding of the interactions between systemic sentinel lymph nodes and standard sentinel lymph nodes may provide important information regarding the underlying mechanism of primary tumor lymphatic drainage. The enhanced permeability and retention effect can also play a role in the fluorescence of systemic sentinel lymph nodes, especially if these lymph nodes are inflamed. In this case, we can even imagine that this new technique will highlight more instances of lymph node–positive colorectal cancer.

International Registered Report Identifier (IRRID)

PRR1-10.2196/17976

A thiopyrylium salt for PET/NIR-II tumor imaging and image-guided surgery

All tumor imaging modalities have resolution limits below which deeply situated small metastatic foci may not be identified. Moreover, incomplete lesion excision will affect the outcomes of the patients. Scintigraphy is adept in locating lesions, and second near-infrared window (NIR-II) imaging may allow precise real-time tumor delineation. To achieve complete excision of all lesions, multimodality imaging is a promising method for tumor identification and management. Here, a NIR-II thiopyrylium salt, XB1034, was first synthesized and bound to cetuximab and trans-cyclooctene (TCO) to produce XB1034-cetuximab-TCO. This probe provides excellent sensitivity and high temporal resolution NIR-II imaging in mice bearing tumors developed from human breast cancer cells MDA-MB-231. To enable PET imaging, 68 Ga-NETA-tetrazine is subsequently injected into the mice to undergo a bio-orthogonal reaction with the preinjected XB1034-cetuximab-TCO. PET images achieved in the tumor models using the pretargeting strategy are of much higher quality than those obtained using the direct radiolabeling method. Moreover, real-time NIR-II imaging allows accurate tumor excision and sentinel lymph node mapping. In conclusion, XB1034 is a promising molecular imaging probe for tumor diagnosis and treatment.

Near-infrared fluorescence-guided surgery using indocyanine green facilitates secure infrapyloric lymph node dissection during laparoscopic distal gastrectomy

PURPOSE

We aimed to investigate the usefulness of near-infrared indocyanine green (ICG)-enhanced fluorescence guidance for infrapyloric LN dissection in laparoscopic distal gastrectomy.

METHODS

This study enrolled patients with early gastric cancer scheduled for laparoscopic distal gastrectomy. After intraoperative submucosal injection of ICG (0.1 mg/mL), LN dissection was conducted under near-infrared ICG fluorescence guidance. The operation time, bleeding events during infrapyloric LN dissection were analyzed. Cases were retrospectively 1:3 propensity-score matched to patients who underwent laparoscopic distal gastrectomy without ICG injection.

RESULTS

The mean time from midline omentectomy to exposure of the right gastroepiploic vein was significantly shorter in the ICG group (n = 20) than in the non-ICG group (n = 60) (13.05 ± 5.77 vs 18.68 ± 7.92 min; p = 0.001), and the incidence of bleeding during infrapyloric LN dissection was lower in the ICG group (20% vs 68.3%, p < 0.001). The two groups did not differ significantly regarding the number of LNs retrieved from the infrapyloric area (p = 0.434).

CONCLUSIONS

Near-infrared ICG fluorescence guidance facilitates safe and fast infrapyloric LN dissection in laparoscopic distal gastrectomy.

Value of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and Sentinel Lymph Node Biopsy in Endometrial Cancer Patients: A Prospective Study

The aim of this study is to define the role of preoperative positron emission tomography/computed tomography (PET/CT) scan and sentinel lymph node (SLN) biopsy for nodal metastasis detection in Endometrial Cancer (EC) patients. From January 2014 to August 2016 patients affected by EC scheduled for surgery underwent PET/CT scan and SLN mapping with indocyanine-green. Patients with suspicious lymph nodes at FDG-PET/CT underwent selective pelvic lymphadenectomy. In case of undetectable SLN, no further lymphadenectomy was performed if PET/CT scan was negative. Basic descriptive statistics were used to describe outcomes. A total of 83 patients were enrolled in the study. PET/CT scan was suggestive of nodal involvement in 15 patients. SLN were detected bilaterally in 78% of patients. Detection rate was influenced by patients' BMI and surgical learning curve. Five patients were node-positive: all of these had hypermetabolic nodes on PET/CT scan; in one patient SLN was not detected. Ten out of 15 patients with suspicious nodes on PET/CT scan were node-negative. After a median follow up of 24 months all patients are alive. Four patients experienced recurrent disease. No nodal relapse was recorded. Lymphatic mapping with sentinel node biopsy is able to reduce morbidity associated with pelvic lymphadenectomy. Sentinel node assessment is a feasible and appealing procedure and should be performed in a specialized center. Detection rate strongly improves with learning curve, while is reduced in morbidly obese patients. PET/CT scan shows high sensitivity but moderate specificity for nodal metastasis and may help to avoid nodal dissection in patients with sentinel node mapping failure.

Failure of sentinel lymph node mapping in a patient with endometrial cancer with chronic lymphocytic leukemia: A case report

We aimed to report a detection failure of sentinel lymph node (SLN) mapping via indocyanine green in a patient with endometrial cancer with a previous history of chronic lymphocytic leukemia (CLL), which is a potential risk factor to obstruct lymphatic channels. A 64-year-old woman with a 12-year history of CLL presented to the clinic with grade 2 endometrioid carcinoma. The patient underwent laparoscopic surgical staging. Indocyanine green was used intraoperatively to locate the SLN. No lymph node or lymphatic vessels were identified during SLN mapping. At the final pathology, the morphological findings of CLL were detected in the lymph nodes without metastasis of endometrial cancer. Sentinel lymph node mapping failure due to obstruction of lymphatic channels in a patient with CLL was demonstrated in this study. This is the first report to the best of our knowledge showing SLN mapping failure in the presence of lymphoproliferative diseases.

TMTP1-modified Indocyanine Green-loaded Polymeric Micelles for Targeted Imaging of Cervical Cancer and Metastasis Sentinel Lymph Node in vivo

Metastasis is one of the most threatening aspects of cervical cancer. We developed a method to intraoperatively map the primary tumor, metastasis and metastatic sentinel lymph nodes (SLNs), providing real-time intraoperative guidance in cervical cancer.

Methods: TMTP1, a tumor metastasis targeting peptide, was employed to modify the indocyanine green (ICG)-loaded poly (ethylene glycol)- poly (lactic-co-glycolic acid) (PEG-PLGA) micelles. The cervical cancer subcutaneous tumor model and lung metastasis model were established to determine the active targeting of ICG-loaded TMTP1-PEG-PLGA micelles (ITM) for the primary tumor and occult metastasis of cervical cancer. Human cervical cancer HeLa cells engineered by firefly luciferase were injected into the right hocks of BALB/c nude mice to develop the SLN metastasis model. The ITM and control ICG-loaded PEG-PLGA micelles (IM) were injected into the right hind footpads in the SLN metastasis model, and the migration and retention of micelles were recorded under near-infrared fluorescence. K14-HPV16 transgenic mice were also used to detect the image capability of ITM to target cancerous lesions.

Results: ITM could actively target imaging of the primary tumor and cervical cancer metastasis. ITM quickly diffused from the injection site to SLNs along lymphatic capillaries and remained in the SLNs for 12 h. Moreover, ITM specifically accumulated in the tumor metastatic SLNs (T-SLNs), which could be successfully distinguished from normal SLNs (N-SLNs).

Conclusion: ITM could achieve active targeting of the primary tumor, metastasis and T-SLNs, providing precise and real-time intraoperative guidance for cervical cancer.

Characterization and validation of multimodal annihilation-gamma/near-infrared/visible laparoscopic system

Minimally invasive robotic surgery using fluorescence-guided images with a video laparoscope has been widely used because of its advantages of small incision, fast recovery time, and efficiency. However, the penetration depth limitation of fluorescence is a disadvantage caused by the absorption and scattering in tissues and blood cells. If this limitation can be overcome by additional imaging modalities, the surgical procedure can be quite efficient and precise. High-energy annihilation-gamma photons have a stronger penetration capability than visible and fluorescence photons. To characterize and validate a multimodal annihilation-gamma/near-infrared (NIR)/visible laparoscopic imaging system, an internal detector composed of an annihilation-gamma detector and an optical system was assembled inside a surgical stainless pipe with an outer diameter of 15.8 mm and an external detector with a dimension of 100  ×  100  mm2 placed at the opposite side of the internal detector. Integrated images of 511-keV gamma rays, NIR fluorescence, and visible light were obtained simultaneously. The 511-keV gamma image could be clearly seen with the acquisition of 5 s, while NIR and visible images could be presented in real time. This multimodal system has the potential for improving the surgery time and the quality of patient care.

Robotic-Assisted Sentinel Lymph Node Mapping With Indocyanine Green in Pelvic Malignancies: A Systematic Review and Meta-Analysis

Objective: Newer technologies such as near-infrared (NIR) imaging of the fluorescent dye indocyanine green (ICG) and daVinci Xi Surgical System have become promising tools for sentinel lymph node (SLN) mapping. This meta-analysis was conducted to comprehensively evaluate the diagnostic value of SLN in assessing lymph nodal metastasis in pelvic malignancies, using ICG with NIR imaging in robotic-assisted surgery. Materials and Methods: A literature search was conducted using PubMed for studies in English before April 2019. The detection rate, sensitivity of SLN detection of metastatic disease, and factors associated with successful mapping (sample size, study design, mean age, mean body mass index, type of cancer) were synthesized for meta-analysis. Results: A total of 17 articles including 1,059 patients were finally included. The reported detection rates of SLN ranged from 76 to 100%, with a pooled average rate of 95% (95% CI: 93-97; 17 studies). The sensitivity of SLN detection of metastatic disease ranged from 50 to 100% and the pooled sensitivity was 86% (95% CI: 75-94; 8 studies). There were no complications related to ICG administration reported. Conclusions: NIR imaging system using ICG in robotic-assisted surgery is a feasible and safe method for SLN mapping. Due to its promising performance, it is considered to be an alternative to a complete pelvic lymph node dissection.

Feasibility of hand-assisted laparoscopic sentinel node biopsy in open endometrial cancer surgery

Background: The aim of this preliminary retrospective study was to assess the feasibility and accuracy of Indocyanine Green (ICG) sentinel node (SLN) sampling using a laparoscopic camera during open endometrial cancer surgery.Material and methods: Retrospective study. Fourteen women with endometrial cancer, not fit for a complete laparoscopic staging, underwent SLN mapping using the IMAGE1 camera during open surgery.Results: The median age of patients was 67 (range 33-86) years. Median BMI was 31 (range 23-58). Mean operative time 157.5 minutes and hospital stay three days. The overall detection rate of SLN mapping was 93%. Bilateral detection was 86%. No post-operative short or long-term complications were observed.Conclusions: Real-time NIR technology supported by the IMAGE1 S is a reliable system and represents a promising method for SLN mapping in selected cases with EC and severe surgical risks, during 48 traditional open approaches. The use of laparoscopy ICG in open surgery seems to be a feasible and useful tool for the detection of SLN in endometrial cancer patients with intraoperative and/or postoperative high morbidity risk. It represents a valid alternative to robotic surgery, particularly in countries and centers where the robotic platform or SPY system for open surgery are not available.

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.

Current state of sentinel lymph nodes for women with endometrial cancer

Sentinel lymph node (SLN) biopsy has been investigated as an alternative to conventional pelvic and para-aorticlymphadenectomy for the surgical staging of endometrial cancer. Clinical trials have established the accuracy of sentinel nodes in the detecting metastatic disease. Novel advancements in tracers from the historically favored blue dyes and radio labeled colloids to near infrared imaging of fluorescent dyes has improved the ability to detect sentinel nodes and increased options for surgeons. The uterine cervix has been shown to be a feasible and accurate injection site for tracer, though the potential for under-evaluation of the para-aortic nodes remains a controversy, particularly for high-risk cancers. Additionally, sentinel node evaluation provides qualitatively different information than traditional staging techniques by identifying lymph nodes outside of traditional sampling locations and through the identification of very low volume meta static disease implants, such as isolated tumor cells. It is unclear how this altered staging information should be interpreted, guide the prescription of adjuvant therapy and its impact on long term clinical outcomes such as recurrence and survival. In this review we will discuss the evidence that has supported the use of the SLN technique in the staging of endometrial cancer, the options for surgical technique and the implications of managing the results of staging pathology.

Novel near-infrared II aggregation-induced emission dots for in vivo bioimaging

Near-infrared II fluorescence imaging holds great promise for in vivo imaging and imaging-guided surgery with deep penetration and high spatiotemporal resolution. However, most NIR-II aromatic luminophores suffer from the notorious aggregation-caused quenching (ACQ) effect in the aqueous solution, which largely hinders their biomedical application in vivo. In this study, the first NIR-II organic aggregation-induced emission (AIE) fluorophore (HLZ-BTED), encapsulated as nanoparticles (HLZ-BTED dots) for in vivo biomedical imaging, was designed and synthesized. The NIR-II AIE HLZ-BTED dots showed high temporal resolution, high photostability, outstanding water-solubility and biocompatibility in vitro and in vivo. The HLZ-BTED dots were further used for long-term breast tumor imaging and visualizing tumor-feeding blood vessels, long-term hind limb vasculature and incomplete hind limb ischemia. More importantly, as a proof-of-concept, this is the first time that non-invasive and real-time NIR-II imaging of the gastrointestinal tract in health and disease has been performed, making the AIE dots a promising tool for gastrointestinal (GI) tract research, such as understanding the healthy status of GI peristalsis, diagnosing and evaluating intestinal motility dysfunction, and assessing drug effects on intestinal obstruction.

Photoacoustic Ophthalmoscopy: Principle, Application, and Future Directions

Photoacoustic ophthalmoscopy (PAOM) is a novel, hybrid, non-ionizing, and non-invasive imaging technology that has been used to assess the retina. PAOM can provide both anatomic and functional retinal characterizations with high resolution, high sensitivity, high contrast, and a high depth of penetration. Thus, ocular diseases can be precisely detected and visualized at earlier stages, resulting in an improved understanding of pathophysiology, improved management, and the improved monitoring of retinal treatment to prevent vision loss. To better visualize ocular components such as retinal vessels, choroidal vessels, choroidal neovascularization, retinal neovascularization, and the retinal pigment epithelium, an advanced multimodal ocular imaging platform has been developed by a combination of PAOM with other optical imaging techniques such as optical coherence tomography (OCT), scanning laser ophthalmoscopy (SLO), and fluorescence microscopy. The multimodal images can be acquired from a single imaging system and co-registered on the same image plane, enabling an improved evaluation of disease. In this review, the potential application of photoacoustic ophthalmoscopy in both research and clinical diagnosis are discussed as a medical screening technique for the visualization of various ocular diseases. The basic principle and requirements of photoacoustic ocular imaging are introduced. Then, various photoacoustic microscopy imaging systems of the retina in animals are presented. Finally, the future development of PAOM and multimodal imaging is discussed.

Noninvasive detection of cancer spread to lymph nodes: A review of molecular imaging principles and protocols

Identification of cancer spread to tumor-draining lymph nodes offers critical information for guiding treatment in many cancer types. Current clinical methods of nodal staging are invasive and can have substantial negative side effects. Molecular imaging protocols have long been proposed as a less invasive means of nodal staging, having the potential to enable highly sensitive and specific evaluations. This review article summarizes the current status and future perspectives for molecular targeted nodal staging.

Impact of Sentinel Node Approach in Gynecologic Cancer on Training Needs

STUDY OBJECTIVE

We sought to estimate the impact of sentinel nodes in gynecologic oncology on fellowship training and discuss potential solutions.

DESIGN

Retrospective multi-institution cohort (Canadian Task Force classification II-2).

SETTING

Three tertiary cancer referral cancer centers.

PATIENTS

Patients with endometrial and vulvar cancer undergoing lymph node evaluation.

INTERVENTIONS

Patient history and fellow case volumes were evaluated retrospectively for type of lymph node assessment.

MEASUREMENTS AND MAIN RESULTS

Minimally invasive endometrial cancer and vulvar cancer fellow case volumes in 3 large institutions were reviewed and average annual volumes calculated for each clinical gynecologic oncology fellow. For vulvar cancer, probabilities of sentinel lymph node mapping and laterality of lesions were estimated from the literature. For endometrial cancer, estimates of lymphadenectomy rates were determined using probabilities calculated from our historic database and from review of the literature. Modeling the approaches to lymphadenectomy in endometrial cancer (full, selective, and sentinel), 100% versus 68% versus 24%, respectively, of patients would require complete pelvic lymphadenectomy and 100% versus 34% versus 12% would require para-aortic lymphadenectomy. In vulvar cancer, rates of inguinal femoral lymphadenectomy are expected to drop from 81% of unilateral groins to only 12% of groins.

CONCLUSIONS

Sentinel lymph node biopsy for endometrial and vulvar cancer will play an increasing role in practice, and coincident with this will be a dramatic decrease in pelvic, para-aortic, and inguinal femoral lymphadenectomies. The declining numbers will require new strategies to maintain competency in our specialty. New approaches to surgical training and continued medical education will be necessary to ensure adequate training for fellows and young faculty across gynecologic surgery.

Fluorescence of Deep Infiltrating Endometriosis During Laparoscopic Surgery: A Preliminary Report on 6 Cases

BACKGROUND

The standard treatment of rectovaginal deep infiltrating endometriosis nodules (RVDIEN) consists in their surgical removal. RVDIEN are anatomically neovascularized. Indocyanine green (ICG) reveals vascularized structures when becoming fluorescent after exposure to near-infrared (NIR) light. This study aims to evaluate if fluorescence-guided surgery can improve the laparoscopic resection of RVDIEN, thus avoiding a rectal perforation.

MATERIALS AND METHODS

Patients with a symptomatic RVDIEN, scheduled for a laparoscopic rectal shaving, were enrolled in the study. Technically, the RVDIEN was targeted and removed with the help of the NIR imager device Image 1 Spies (Karl Storz GmBH & Co KG, Tuttlingen, Germany) or Visera Elite II (Olympus Europe SE & Co KG, Hamburg, Germany), after an intraoperative, intravenous injection of ICG (0.25 mg/kg).

RESULTS

Six patients underwent a fluorescence-guided laparoscopic shaving procedure for the treatment of a nonobstructive RVDIEN. Fluorescence of the RVDIEN was observed in all the patients. In one patient, once the main lesion was removed, the posterior vaginal fornix still appeared fluorescent and was removed. No intraoperative rectal perforation occurred. The postoperative hospital stay was 2 days. No postoperative rectovaginal fistula occurred within a median follow-up of 16 months (range = 2-23 months).

CONCLUSION

In this preliminary study, fluorescence-guided laparoscopy appeared to help in separating the RVDIEN from the healthy rectal tissue, without rectal perforation. Moreover, this technique was helpful in deciding if the resection needed to be enlarged to the posterior vaginal fornix.

A practical guide for the use of indocyanine green and methylene blue in fluorescence-guided abdominal surgery

Near-infrared (NIR) fluorescence imaging is gaining clinical acceptance over the last years and has been used for detection of lymph nodes, several tumor types, vital structures and tissue perfusion. This review focuses on NIR fluorescence imaging with indocyanine green and methylene blue for different clinical applications in abdominal surgery with an emphasis on oncology, based on a systematic literature search. Furthermore, practical information on doses, injection times, and intraoperative use are provided.

Melanoma & nuclear medicine: new insights & advances

The contribution of nuclear medicine to management of melanoma patients is increasing. In intermediate-thickness N0 melanomas, lymphoscintigraphy provides a roadmap for sentinel node biopsy. With the introduction of single-photon emission computed tomography images with integrated computed tomography (SPECT/CT), 3D anatomic environments for accurate surgical planning are now possible. Sentinel node identification in intricate anatomical areas (pelvic cavity, head/neck) has been improved using hybrid radioactive/fluorescent tracers, preoperative lymphoscintigraphy and SPECT/CT together with modern intraoperative portable imaging technologies for surgical navigation (free-hand SPECT, portable gamma cameras). Furthermore, PET/CT today provides 3D roadmaps to resect 18F-fluorodeoxyglucose-avid melanoma lesions. Simultaneously, in advanced-stage melanoma and recurrences, 18F-fluorodeoxyglucose-PET/CT is useful in clinical staging and treatment decision as well as in the evaluation of therapy response. In this article, we review new insights and recent nuclear medicine advances in the management of melanoma patients.

Sentinel Lymph Nodes Mapping in Cervical Cancer a Comprehensive Review

Objective

A comprehensive literature search for more recent studies pertaining to sentinel lymph node mapping in the surveillance of cervical cancer to assess if sentinel lymph node mapping has sensitivity and specificity for evaluation of the disease; assessment of posttreatment response and disease recurrence in cervical cancer.

Materials and Methods

The literature review has been constructed on a step wise study design that includes 5 major steps. This includes search for relevant publications in various available databases, application of inclusion and exclusion criteria for the selection of relevant publications, assessment of quality of the studies included, extraction of the relevant data and coherent synthesis of the data.

Results

The search yielded numerous studies pertaining to sentinel lymph node mapping, especially on the recent trends, comparison between various modalities and evaluation of the technique. Evaluation studies have appraised high sensitivity, high negative predictive values and low false-negative rate for metastasis detection using sentinel lymph node mapping. Comparative studies have established that of all the modalities for sentinel lymph node mapping, indocyanine green sentinel lymph node mapping has higher overall and bilateral detection rates. Corroboration of the deductions of these studies further establishes that the sentinel node detection rate and sensitivity are strongly correlated to the method or technique of mapping and the history of preoperative neoadjuvant chemotherapy.

Conclusions

The review takes us to the strong conclusion that sentinel lymph node mapping is an ideal technique for detection of sentinel lymph nodes in cervical cancer patients with excellent detection rates and high sensitivity. The review also takes us to the supposition that a routine clinical evaluation of sentinel lymph nodes is feasible and a real-time florescence mapping with indocyanine green dye gives better statistically significant overall and bilateral detection than methylene blue.

A new fluorescence imaging technique for visualizing hepatobiliary structures using sodium fluorescein: result of a preclinical study in a rat model

BACKGROUND

Near-infrared fluorescence imaging has been recently applied in the field of hepatobiliary surgery. Our objective was to apply blue light fluorescence imaging to cholangiography and liver mapping during laparoscopic surgery. Therefore, we designed a preclinical study to evaluate the feasibility of using blue light fluorescence for cholangiography and liver mapping in a rat model.

METHODS

Sodium fluorescein solution (1 mL to each individual) were administered intravenously to 20 male Sprague-Dawley rats (6 weeks old, 200-250 g), after laparotomy. Whole abdominal organs were observed under blue light (at a wavelength of 440-490 nm) emitted from a commercialized LED curing light.

RESULTS

Immediately after the tracer solution was administered into the circulatory system of the rat, it was possible to visualize the location of the kidneys and the bile duct under blue light emitted from the light source. The liver was vaguely stained green by the tracer, while the ureters were not. After establishing biliary retention via duct clamping in the left lateral segment of the liver, the green color of the segment became distinct by the tracer, which showed vague coloration following release of the clamp.

CONCLUSION

We established the preclinical basis for using blue light fluorescence cholangiography and liver mapping in this study. The clinical feasibility of these techniques during laparoscopic cholecystectomy and hepatectomy remained to be demonstrated.