Indocyanine green can stand alone in detecting sentinel lymph nodes in cervical cancer

Evaluation of the benefit of indocyanine green as an educational and practical tool for ureteral identification in laparoscopic pelvic surgery: a cross-sectional study

BACKGROUND

Indocyanine green (ICG) is a visible near-infrared fluorescent dye. Several studies have reported its benefit in identifying important anatomical structures, tissue vascularization, and sentinel lymph nodes in the case of tumors. Studies have shown that ICG is critical and safe in gynecologic surgeries. However, research on how ICG dye can help surgeons in laparoscopic surgeries correctly identify the course of the ureter has yet to be further investigated.

METHOD

This cross-sectional study enrolled 62 gynecology attending and resident surgeons who were asked to identify the course of the ureter on images of laparoscopic surgeries. The results were then compared with images in which ICG dye highlighted the course of the ureter. The purpose of this study was to detect the ability of surgical assistants and residents to adequately identify the course of the ureter in laparoscopic pelvic surgeries.

RESULTS

No statistically significant differences were found in terms of year of residency, years of experience, number of laparoscopic procedures attended, and correct identification of ureter course. ICG proved useful in identifying the correct ureteral trajectory.

CONCLUSIONS

ICG can be a valuable tool to improve the correct identification of ureters and improve surgical outcomes.

Feasibility and Diagnostic Accuracy of Ultrastaging in the Detection of Micrometastases in Sentinel and Non-sentinel Lymph Nodes in Cervical Cancer: A Single-Center Retrospective Study With a Five-Year Follow-Up Period

BACKGROUND

Cervical cancer is the fourth most common cause of malignant tumor-related deaths among women in developing nations. Cervical cancer has been estimated to cause 527.600 new cases and 265.700 deaths globally per year.

OBJECTIVES

This study aimed to evaluate patients with cervical cancer by ultrastaging all the lymph nodes (LN), sentinel LN (SLN) and non-SLN, to increase the sensitivity of the detection of LN metastases and the diagnostic accuracy in cervical cancer with a five-year follow-up.

MATERIALS AND METHODS

This is a retrospective study of 14 cervical cancer cases from 2017 to 2019 at the Municipal Emergency Clinical Hospital of Timisoara, Romania. The cases were selected based on their high risk of LN involvement but negative intraoperative pathologic LN. After re-evaluating all paraffin block biopsy samples from 29 cases, 14 cases were included in the study, which met all criteria for ultrastaging on surgical biopsy samples.

RESULTS

Patients' ages included in the study ranged from 43 to 70 years (median: 57.14 years). According to the International Federation of Gynecology and Obstetrics (FIGO) staging, the majority of the patients were in stage IB: seven cases (50%). The study revealed a positive correlation between patient age and FIGO staging, with Pearson's correlation coefficient of 0.707 and a p-value of less than 0.05, indicating that older patients were more likely to be diagnosed with a higher FIGO stage. The mean follow-up was 34.5 months, and the median follow-up was 36 months (range: 6-60 months). We obtained 167 nodes, with a mean of 11.92 nodes/case. Twenty-one LN were found to be positive with the ultrastaging method. We detected 11 LN with macrometastases (MAC) (52.38%), seven with micrometastasis (MIC) (33.3%), and three with tumor cell islets (14.4%). That would be 13% of newly diagnosed ultrastaging cases as positive nodes. This ultrastaging method detected nodal MIC in eight (57.1%) out of the 14 patients, who initially tested negative for LN involvement using the routine Hematoxylin and Eosin (HE) method. The detection of micrometastases in these patients underscored the superior sensitivity of ultrastaging, which was further highlighted by the subsequent relapse of four (28.57%) out of these eight patients. The study also found no correlation between the FIGO standardization and the number of MIC found in these patients.

CONCLUSIONS

Predicting cervical LN metastasis (LNM) is crucial for improving survival rates and reducing recurrence. Very few small cohort studies used an ultrastaging method to assess non-SLNs; most of them only assessed SLNs. We showed in our study that the ultrastaging method, both in the case of SLN and non-SLN, is superior compared with H&E analysis, with a 13% rate of new positive nodule diagnosis. Metastatic involvement of non-SLN was found in over 50% of all cases (8/14) according to the ultrastaging method. Additionally, our study confirms that the sensitivity of SLN ultrastaging is high for the presence of both MIC and MAC in SLN pelvic LN. As a result, we feel that ultrastaging is the most effective method for SLN analysis in patients with early-stage cervical cancer, and bilateral detection is preferable, significantly reducing false-negative results. The routine use of SLN along with ultrastaging would lead to more accurate surgical staging and better oncological follow-up of cases.

Comparative study using indocyanine green and patent blue dye for sentinel lymph node biopsy in patients with early-stage cervical cancer

BACKGROUND

Lymphatic involvement is the most important prognostic factor in early-stage cervical cancer. Sentinel lymph node biopsy is a viable alternative to systematic lymphadenectomy and may identify metastases more precisely.

OBJECTIVE

To compare two tracers (indocyanine green and patent blue) to detect sentinel nodes.

METHODS

A single-center, retrospective study of women treated due to early-stage cervical cancer (International Federation of Gynecology and Obstetrics 2009 IA1 with lymphovascular invasion, IA2, and IB1). Location and tracer of all detected sentinel nodes had been documented for a prospective, multicenter trial (SENTIX trial). All sentinel nodes were sent to frozen section and final analysis through ultrastaging using a standard protocol.

RESULTS

Overall, 103 patients were included. Bilateral detection rate for indocyanine green (93.2%) was significantly higher than for blue dye (77.7%; p=0.004). Their combined use significantly increased the bilateral detection to 99.0% (p=0.031). While 97.4% of all sentinel nodes were located below the common iliac vessels, no para-aortic nodes were labeled. Simultaneous bilateral detection with both tracers was found in 71.8% of the cases, of which the sentinel nodes were identical in 91.9%. Nine positive nodes were detected among seven patients (6.8%), all marked with indocyanine green while patent blue labeled six. Frozen section failed to detect one of three macrometastases and three of four micrometastases (sensitivity 43%; negative prediction value 96%).

CONCLUSION

Anatomical distribution and topographic localization of the sentinel nodes obtained with these tracers were not different. Indocyanine green provided a significantly higher bilateral detection rate and had superior sensitivity to detect positive nodes compared with patent blue. Combining indocyanine green and blue dye increased the bilateral detection rate significantly.

Current applications of indocyanine green (ICG) in abdominal, gynecologic and urologic surgery: a meta-review and quality analysis with use of the AMSTAR 2 instrument

BACKGROUND

Indocyanine green (ICG) is an injectable fluorochrome that has recently gained popularity as a means of assisting intraoperative visualization during laparoscopic and robotic surgery. Many systematic reviews and meta-analyses have been published. We conducted a meta-review to synthesize the findings of these studies.

METHODS

PubMed and Embase were searched to identify systematic reviews and meta-analyses coping with the uses of ICG in abdominal operations, including Metabolic Bariatric Surgery, Cholecystectomy, Colorectal, Esophageal, Gastric, Hepato-Pancreato-Biliary, Obstetrics and Gynecology (OG), Pediatric Surgery, Surgical Oncology, Urology, (abdominal) Vascular Surgery, Adrenal and Splenic Surgery, and Interdisciplinary tasks, until September 2023. We submitted the retrieved meta-analyses to qualitative analysis based on the AMSTAR 2 instrument.

RESULTS

We identified 116 studies, 41 systematic reviews (SRs) and 75 meta-analyses (MAs), spanning 2013-2023. The most thoroughly investigated (sub)specialties were Colorectal (6 SRs, 25 MAs), OG (9 SRs, 15 MAs), and HPB (4 SRs, 12 MAs). Interestingly, there was high heterogeneity regarding the administered ICG doses, routes, and timing. The use of ICG offered a clear benefit regarding anastomotic leak prevention, particularly after colorectal and esophageal surgery. There was no clear benefit regarding sentinel node detection after OG. According to the AMSTAR 2 tool, most meta-analyses ranked as "critically low" (34.7%) or "low" (58.7%) quality. There were only five meta-analyses (6.7%) that qualified as "moderate" quality, whereas there were no "high" quality reviews.

CONCLUSIONS

Regardless of the abundance of pertinent literature and reviews, surgeons should be cautious when interpreting their results on ICG use in abdominal surgery. Future reviews should focus on ensuring methodological vigor; establishing clear protocols of ICG dose, route of administration, and timing; and improving reporting quality. Other sources of data (e.g., registries) and novel methods of data analysis (e.g., machine learning) might also contribute to an enhanced role of ICG as a decision-making tool in surgery.

Sentinel Lymph Node Mapping: Current Applications and Future Perspectives in Gynecology Malignant Tumors

The sentinel lymph nodes (SLNs) is a group of lymph nodes initially involved in the metastatic spread of cancer cells. SLN mapping refers to intraoperative localization and biopsy of SLNs with specific tracers to assess lymph node metastases. It is widely used in a variety of tumor surgeries for its high sensitivity and high negative predictive value. In the evaluation of the status of lymph node metastases in gynecological malignancies, it has received increasingly more attention due to its minor invasiveness, few complications, and high diagnosis rate. The National Comprehensive Cancer Network (NCCN) guidelines provide an excellent introduction to the indications and methods of SLN techniques in vulvar, cervical, and endometrial cancers, but they provide little explanation about some specific issues. In this review, we summarize different dyes and injection methods and discuss the indications of application and the clinical trials of SLN mapping in gynecological malignant tumors, aiming to provide a reference for the rational application of sentinel techniques in gynecology malignant tumors before relevant guidelines are updated.

Consensus Conference Statement on the General Use of Near-infrared Fluorescence Imaging and Indocyanine Green Guided Surgery: Results of a Modified Delphi Study

BACKGROUND

In recent decades, the use of near-infrared light and fluorescence-guidance during open and laparoscopic surgery has exponentially expanded across various clinical settings. However, tremendous variability exists in how it is performed.

OBJECTIVE

In this first published survey of international experts on fluorescence-guided surgery, we sought to identify areas of consensus and nonconsensus across 4 areas of practice: fundamentals; patient selection/preparation; technical aspects; and effectiveness and safety.

METHODS

A Delphi survey was conducted among 19 international experts in fluorescence-guided surgery attending a 1-day consensus meeting in Frankfurt, Germany on September 8th, 2019. Using mobile phones, experts were asked to anonymously vote over 2 rounds of voting, with 70% and 80% set as a priori thresholds for consensus and vote robustness, respectively.

RESULTS

Experts from 5 continents reached consensus on 41 of 44 statements, including strong consensus that near-infrared fluorescence-guided surgery is both effective and safe across a broad variety of clinical settings, including the localization of critical anatomical structures like vessels, detection of tumors and sentinel nodes, assessment of tissue perfusion and anastomotic leaks, delineation of segmented organs, and localization of parathyroid glands. Although the minimum and maximum safe effective dose of ICG were felt to be 1 to 2 mg and >10 mg, respectively, there was strong consensus that determining the optimum dose, concentration, route and timing of ICG administration should be an ongoing research focus.

CONCLUSIONS

Although fluorescence imaging was almost unanimously perceived to be both effective and safe across a broad range of clinical settings, considerable further research remains necessary to optimize its use.

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.

Consensus Guidelines for the Use of Fluorescence Imaging in Hepatobiliary Surgery

OBJECTIVE

To establish consensus recommendations for the use of fluorescence imaging with indocyanine green (ICG) in hepatobiliary surgery.

BACKGROUND

ICG fluorescence imaging has gained popularity in hepatobiliary surgery in recent years. However, there is varied evidence on the use, dosage, and timing of administration of ICG in clinical practice. To standardize the use of this imaging modality in hepatobiliary surgery, a panel of pioneering experts from the Asia-Pacific region sought to establish a set of consensus recommendations by consolidating the available evidence and clinical experiences.

METHODS

A total of 13 surgeons experienced in hepatobiliary surgery and/or minimally invasive surgery formed an expert consensus panel in Shanghai, China in October 2018. By the modified Delphi method, they presented the relevant evidence, discussed clinical experiences, and derived consensus statements on the use of ICG in hepatobiliary surgery. Each statement was discussed and modified until a unanimous consensus was achieved.

RESULTS

A total of 7 recommendations for the clinical applications of ICG in hepatobiliary surgery were formulated.

CONCLUSIONS

The Shanghai consensus recommendations offer practical tips and techniques to augment the safety and technical feasibility of ICG fluorescence-guided hepatobiliary surgery, including laparoscopic cholecystectomy, liver segmentectomy, and liver transplantation.

Controversies in Sentinel Lymph Node Biopsy for Gynecologic Malignancies

OBJECTIVE

Sentinel lymph node (SLN) biopsy represents an evolution in the advancement of minimally invasive surgical techniques for gynecologic cancers. Prospective and retrospective studies have consistently shown its accuracy in the detection of lymph node metastases for endometrial and cervical cancers. However, consistent with any emerging surgical technique in the early phases of adoption, new questions have arisen regarding its application and impact. This paper served as a scoping review to identify the key controversies that have arisen in the field of SLN biopsy for endometrial and cervical cancers.

DATA SOURCES

Several key controversies were identified, and PubMed, the Cochrane Library (cochranelibrary.com) advanced search function, and the National Comprehensive Cancer Network guidelines were searched for supporting evidence. These included search terms such as "the accuracy of SLN biopsy for high grade endometrial cancer or cervical cancers >2-cm," "cost effectiveness of SLN biopsy for gynecologic cancers," "clinical significance of low volume metastases in endometrial cancer," "morbidity of SLN biopsy for endometrial and cervical cancer," and "impact on cancer survival of SLN biopsy for endometrial and cervical cancer."

METHODS OF STUDY SELECTION

Studies were selected for review if they included significant numbers of patients, were level I evidence, or were prospective trials. Where this level of evidence failed to exist, seminal observational series that were published in high-quality journals were included.

TABULATION, INTEGRATION, AND RESULTS

Similar studies were listed and subcategorized and cross-compared, excluding those that included repeated analyses of the same patient populations. The relevant clinical trials or observational studies were clustered and reviewed for each chosen controversy. Adequate evidence supports the accuracy of SLN biopsy in the staging of high-grade endometrial cancer and cervical cancer, and it seems to be a cost-effective strategy for invasive endometrial cancer. Conclusive evidence was lacking with respect to the oncologic outcomes related to SLN biopsy, the impact on patient morbidity, and whether clinicians should treat isolated tumor cells in SLNs with adjuvant therapy.

CONCLUSION

SLN biopsy is an accepted staging strategy for cervical and endometrial cancer surgery; however, controversies remain in how it can be applied with the most safety and efficacy. These ultimately need to be resolved with further clinical trials and observations of larger series of patients.

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.

Sentinel lymph node biopsy versus pelvic lymphadenectomy in early-stage cervical cancer: a multi-center randomized trial (PHENIX/CSEM 010)

BACKGROUND

There is no accepted strategy for applying sentinel lymph node (SLN) biopsy as an alternative to pelvic lymphadenectomy in cervical cancer. It is unclear whether and when pelvic lymphadenectomy can be safely replaced by SLN biopsy alone.

PRIMARY OBJECTIVE

To comprehensively compare the oncological outcomes of SLN biopsy with pelvic lymphadenectomy in patients with and without SLN metastasis.

STUDY HYPOTHESIS

It is hypothesized that the oncological outcomes provided by SLN biopsy are non-inferior to those of pelvic lymphadenectomy in patients with clinically early-stage cervical cancer if risk-adapted adjuvant treatments are given.

TRIAL DESIGN

All eligible patients will undergo SLN biopsy at the start of surgery. The resected SLNs will be submitted for frozen section examination. and patients will be triaged into the PHENIX-I (SLN-negative) or PHENIX-II (SLN-positive) cohort. In each cohort of this trial, patients will be randomized in a 1:1 ratio into the experimental (SLN biopsy alone) or reference (pelvic lymphadenectomy) arm. Radical hysterectomy will be performed for all patients, and adjuvant treatments will be planned according to post-operative pathological factors.

MAJOR INCLUSION/EXCLUSION CRITERIA

Patients aged between 18 and 65 years with histologically confirmed, untreated stage IA1 (lymphovascular space involvement), IA2, IB1, and IB2 cervical squamous carcinoma, adenocarcinoma, or adenosquamous carcinoma.

PRIMARY ENDPOINT

The primary endpoint is disease-free survival.

SAMPLE SIZE

Estimated sample sizes of 830 and 250 are required to fulfill the study objectives of PHENIX-I and II, respectively.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

As of May 2020, more than 600 eligible patients have been enrolled. Enrollment is expected to be completed by December 2022, and presentation of results is expected in 2026.

TRIAL REGISTRATION

NCT02642471.

Robotic Partial Nephrectomy with Indocyanine Green Fluorescence Navigation

Partial nephrectomy (PN) is a recommended type of treatment of localised renal tumors. Real-time intraoperative imaging technique, such as fluorescence imaging with indocyanine green (ICG) administration helps to improve intraoperative and postoperative outcomes in patients who underwent PN. Our work presents results of patients who underwent robotic PN with ICG navigation. A total of 37 patients underwent robotic PN with application of ICG between April 2015 and May 2019. A total amount of 5 mg of ICG was applied intravenously, and then robotic PN was performed with fluorescent imaging. ICG was used by the surgeon's decision according to unfavourable anatomical properties of tumor or to high R.E.N.A.L. nephrometry score. An exact border between perfused and nonperfused tissue was detected, and exact tumor's branch of the renal artery was clamped. Robotic PN with ICG-fluorescence imaging navigation was performed in 37 cases with a preoperative average diameter of tumor of 31 mm. The mean surgery time was 133 minutes, and the mean estimated blood loss was 190 mL. Arterial clamping was performed in 35 cases. The mean duration of warm ischemia was 14 minutes. Application of ICG enabled specific tumor-supplying vessel clamping in 25 cases. Two complications of grade II according to the Clavien-Dindo classification occurred intraoperatively, and one complication of grade III was observed. Renal function changes showed favourable results for the cases with superselective clamping. Finally, an administration of ICG eases superselective clamping of tumor-specific branch of renal artery and helps to preserve normal renal function with acceptable oncological results.