Near-infrared Fluorescence-guided Sentinel Node Mapping of the Ovary With Indocyanine Green in a Minimally Invasive Setting: A Feasible Study

Future of sentinel node biopsy in ovarian cancer

PURPOSE OF REVIEW

The rationale on the use of sentinel lymph node (SLN) biopsy in the surgical staging of apparent early-stage ovarian cancer (OC) is supported by the fact that diagnostic and prognostic role of systematic staging lymphadenectomy has been determined but its therapeutic significance is still matter of controversy. Moreover, SLN biopsy represents an option to decrease intra- and postoperative morbidity. The present review aims to provide an overview on the current and future role of SLN in OC.

RECENT FINDINGS

Most recent evidence shows that the overall mean per patient SLN detection rate in case of indocyanine green (ICG) alone was 58.6% compared with 95% in case of ICG + technetium, and with 52.9% in case of technetium alone or in combination with blue dye ( P  < 0.001). Site of injection has been reported to be in both ovarian ligaments in majority of studies (utero-ovarian ligament and infundibulo-pelvic ligament), before or after ovarian mass removal, at time of primary or re-staging surgery and by minimally invasive or open approach. Cervical injection has been recently proposed to replace utero-ovarian injection. SLN detection rate in patients with confirmed ovarian malignancy varied across different studies ranging between 9.1% and 91.3% for the injection in the utero-ovarian ligament and migration to pelvic lymph nodes and between 27.3% and 100% for the injection in the infundibulo-pelvic ligament and migration to para-aortic lymph nodes. No intra- or postoperative complication could be attributed directly to SLN biopsy. The sensitivity and the accuracy of SLN in detecting lymphatic metastasis ranged between 73.3-100% and 96-100%, respectively. In up to 40% of positive SLNs, largest metastatic deposit was classified as micro-metastasis or isolated tumor cells, which would have been missed without ultrastaging protocol.

SUMMARY

SLN biopsy represents a promising tool to assess lymph node status in apparent early-stage OC. The type and volume of injected tracer need to be considered as appear to affect SLN detection rate. Ultrastaging protocol is essential to detect low volume metastasis. Sensitivity and accuracy of SLN biopsy are encouraging, providing tracer injection in both uterine and ovarian ligaments.

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.

Sentinel Node Mapping in Ovarian Tumors: A Study Using Lymphoscintigraphy and SPECT/CT

Purpose

Ovarian cancer in the early stage requires a complete surgical staging, including radical lymphadenectomy, implying subsequent risk of morbidity and complications. Sentinel lymph node (SLN) mapping is a procedure that attempts to reduce radical lymphadenectomy-related complications and morbidities. Our study evaluates the feasibility of SLN mapping in patients with ovarian tumors by the use of intraoperative Technetium-99m-Phytate (Tc-99m-Phytate) and postoperative lymphoscintigraphy using tomographic (single-photon emission computed tomography/computed tomography (SPECT/CT)) acquisition.

Materials and Methods

Thirty-two patients with ovarian mass participated in this study. Intraoperative injection of the radiopharmaceutical was performed just after laparotomy and before the removal of tumor in utero-ovarian and suspensory ligaments of the ovary just beneath the peritoneum. Subsequently, pelvic and para-aortic lymphadenectomy was performed for malignant masses, and the presence of tumor in the lymph nodes was assessed through histopathological examination. Conversely, lymphadenectomy was not performed in patients with benign lesions or borderline ovarian tumors. Lymphoscintigraphy was performed within 24 hr using tomographic acquisition (SPECT/CT) of the abdomen and pelvis.

Results

Final pathological examination showed 19 patients with benign pathology, 5 with borderline tumors, and 6 with malignant ovarian tumors. SPECT/CT identified SLNs in para-aortic-only areas in 6 (20%), pelvic/para-aortic areas in 14 (47%), and pelvic-only areas in 7 (23%) cases. Notably, additional unusual SLN locations were revealed in perirenal, intergluteal, and posterior to psoas muscle regions in three patients. We were not able to calculate the false negative rate due to the absence of patients with involved lymph nodes.

Conclusion

SLN mapping using intraoperative injection of radiotracers is safe and feasible. Larger studies with more malignant cases are needed to better evaluate the sensitivity of this method for lymphatic staging of ovarian malignancies.

Mapping sentinel lymph nodes in early-stage ovarian cancer (MELISA) trial - a further step towards lymphadenectomy replacement

OBJECTIVE

Sistematic pelvic and para-aortic lymphadenectomy is part of the staging surgery for early-stage epithelial ovarian cancer, with no therapeutic value. The Mapping Sentinel Lymph Nodes In Early-Stage Ovarian Cancer (MELISA) trial prospectively assessed the SLN detection rate and the diagnostic accuracy of the SLN mapping technique in patients with early-stage epithelial ovarian cancer.

METHODS

This prospective, single-arm study included patients diagnosed with early-stage epithelial ovarian cancer (FIGO stages I and II), via either primary surgery or re-staging surgery. SLN mapping was performed by injecting 0.2 mL of 37-mBq 99mTc-nanocoloid albumin and 2 mL of 2.5 mg/mL indocyanine green into the infundibulopelvic and utero-ovarian ligaments. After removal of SLNs, a complete systematic pelvic and para-aortic lymphadenectomy was performed. SLN Ultrastaging analysis was applied. The primary outcome was the overall SLN detection rate, either with one or both tracers. Secondary outcomes were the diagnostic accuracy of detecting lymph node metastases and factors that may influence SLN detection.

RESULTS

Thirty patients were included. SLNs were identified in 27 patients (90%). Detection rates in primary and re-staging surgery were 89% and 92%, respectively. Para-aortic drainage was the predominant lymphatic spread, observed in 26 of 27 patients. Ultrastaging pathologic reports listed 1 SLN with macrometastasis, 1 with micrometastasis, and 5 with isolated tumor cells; the sensitivity of SLN mapping was 100%, with a false-negative rate of 0%. Univariate analysis showed a nonsignificant higher proportion of patients with uterine fibroids, adenomyosis, and endometriosis (100%, 67%, 67%, respectively) in patients in whom SLNs were not detected.

CONCLUSION

SLN mapping has a high detection rate (90%) and is an accurate technique for detecting lymph node involvement in early-stage epithelial ovarian cancer. SLN mapping is a potential alternative to systematic lymphadenectomy to reduce associated morbidity, but further research is needed to evaluate the impact of SLN mapping on oncologic outcomes and its cost-effectiveness.

Clinical relevance of sentinel lymph node biopsy in early ovarian cancer

The first-line treatment for early ovarian cancer typically involves primary debulking surgery aimed at maximal cytoreduction, alongside adjuvant chemotherapy if clinically indicated. Nodal assessment involving pelvic and para-aortic lymph node dissection is typically performed during the primary debulking surgery. However, the survival benefit of lymphadenectomy in patients with early ovarian cancer has not been well established, and the procedure is associated with longer operation time and higher perioperative complications. With the emergence of minimally invasive surgery as a potential alternative to laparotomy for early ovarian cancer, sentinel lymph node biopsy has been evaluated in this setting. In this review, we summarized the current literature regarding sentinel lymph node biopsy in patients with early ovarian cancer, focusing on the clinical relevance of this method, including its detection rate and diagnostic accuracy. Additionally, we discuss the current status of clinical trials investigating sentinel lymph node biopsy in early ovarian cancer cases.

Feasibility of Sentinel Lymph Node Biopsy in Early-Stage Epithelial Ovarian Cancer: A Systematic Review and Meta-Analysis

Sentinel lymph node biopsy (SLNB) has been widely adopted in the management of early-stage gynaecological cancers such as endometrial, vulvar and cervical cancer. Comprehensive surgical staging is crucial for patients with early-stage ovarian cancer and currently, that includes bilateral pelvic and para-aortic lymph node assessment. SLNB allows the identification, excision and pathological assessment of the first draining lymph nodes, thus negating the need for a full lymphadenectomy. We systematically searched the MEDLINE, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) databases (from inception to 3 November 2022) in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Our search identified 153 articles from which 11 were eligible for inclusion. Patients with clinical stage I-II ovarian cancer undergoing sentinel lymph node biopsy were included. Statistical analysis was performed in RStudio using the meta package, where meta-analysis was performed for the detection. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies C (QUADAS-C) tool. Overall, 11 observational studies met the predetermined criteria and these included 194 women. The meta-analysis showed that the detection rate of sentinel lymph nodes in early-stage ovarian cancer was 94% (95% CI of 86% to 1.00%). Significant heterogeneity was noted among the studies with Q = 47.6, p < 0.0001, I2 = 79% and τ2 = 0.02. Sentinel lymph nodes in early-stage ovarian cancer have a high detection rate and can potentially have applicability in clinical practice. However, considering the small number of participants in the studies, the heterogeneity among them and the low quality of evidence, the results should be interpreted with caution. Larger trials are needed before a change in clinical practice is recommended.

Sentinel lymph node detection in early-stage ovarian cancer: a systematic review and meta-analysis

BACKGROUND

A systematic pelvic and para-aortic lymphadenectomy remains the surgical standard management of early-stage epithelial ovarian cancer. Sentinel lymph node mapping is being investigated as an alternative procedure; however, data reporting sentinel lymph node performance are heterogeneous and limited.

OBJECTIVE

This study aimed to evaluate the detection rate and diagnostic accuracy of sentinel lymph node mapping in patients with early-stage ovarian cancer.

METHODS

A systematic search was conducted in Medline (through PubMed), Embase, Scopus, and the Cochrane Library. We included patients with clinical stage I-II ovarian cancer undergoing a sentinel lymph node biopsy and a pelvic and para-aortic lymphadenectomy as a reference standard. We conducted a meta-analysis for the detection rates and measures of diagnostic accuracy and assessed the risk of bias using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with identifying number CRD42022351497.

RESULTS

After duplicate removal, we identified 540 studies, 18 were assessed for eligibility, and nine studies including 113 patients were analyzed. The pooled detection rates were 93.3% per patient (95% CI 77.8% to 100%; I2=74.3%, p<0.0001), and the sentinel lymph node technique correctly identified 11 of 12 patients with lymph node metastases, with a negative predictive value per patient of 100% (95% CI 97.6% to 100%; I2=0%). The combination of indocyanine green and 99mTc-albumin nanocolloid had the best detection rate (100% (95% CI 94% to 100%; I2=0%)) when injected into the utero-ovarian and infundibulo-pelvic ligaments.

CONCLUSION

Sentinel lymph node biopsy in early-stage ovarian cancer showed a high detection rate and negative predictive value. The utero-ovarian and infundibulo-pelvic injection using the indocyanine green and technetium-99 combination could increase sentinel lymph node detection rates. However, given the limited quality of evidence and the small number of reports, results from ongoing trials are awaited before its implementation in routine clinical practice.

Robotic para-aortic sentinel lymph node mapping in endometrial, cervical, and ovarian cancer

The concept of pelvic sentinel lymph node mapping has been well-investigated in endometrial and cervical cancer. A variety of tracers have been used including blue dye, technetium-99-m (Tc-99 m), and fluorescent tracer indocyanine green. Pelvic sentinel lymph node mapping has shown its safety, efficacy, and diagnostic accuracy, with high sensitivity and negative predictive value of more than 90%, in retrospective cohort studies as well as in prospective trials for robotic surgery. The concept of pelvic sentinel lymph node biopsy has been incorporated in several international guidelines in early-stage endometrial cancer and a subgroup of early-stage cervical cancer, although survival data are still needed to confirm its standard use. The application of para-aortic sentinel lymph node mapping is still in a development phase, but its detection rate and diagnostic accuracy seem to be promising in initial studies. Here, an overview is given of the recent developments in the different methodologies used for identifying para-aortic sentinel lymph nodes in endometrial, cervical, and ovarian cancer.

Opportunities of ICG-fluorescent imaging of lymph nodes during radical cystectomy in patients with bladder cancer: A review

Today, the "golden standard" for the treatment of aggressive forms of bladder cancer is radical cystectomy. An important stage is the pelvic lymphadenectomy. This procedure is crucial for staging the tumor process, determining the subsequent treatment tactics and improving the results of surgery. Currently, the concept of a signaling lymph node (LN) is actively developing, which allows reducing the necessary level of dissection of the pelvic LN. Reducing the number of resected LN increases the level of surgical safety of the patient. The leading method of intraoperative visualization of signal LN is the fluorescence of indocyanine green in the near infrared range of the spectrum. The prospects of this diagnostic method for radical cystectomy in patients with bladder cancer determine the vector of future scientific research in this area.

Can fluorescence-guided surgery improve optimal surgical treatment for ovarian cancer? A systematic scoping review of clinical studies

BACKGROUND

The predicament of achieving optimal surgical intervention faced by surgeons in treating ovarian cancer has driven research into improving intra-operative detection of cancer using fluorescent materials.

OBJECTIVE

To provide a literature overview on the clinical use of intra-operative fluorescence-guided surgery for ovarian cancer, either for cytoreductive surgery or sentinel lymph node (SLN) biopsy.

METHODS

The systematic review included studies from June 2002 until October 2021 from PubMed, Web of Science, and Scopus as well as those from a search of related literature. Studies were included if they investigated the use of fluorescence-guided surgery in patients with a diagnosis of ovarian cancer. Authors charted variables related to study characteristics, patient demographics, baseline clinical characteristics, fluorescence-guided surgery material, and treatment details, and surgical, oncological, and survival outcome variables. After screening 2817 potential studies, 24 studies were included.

RESULTS

Studies investigating the role of fluorescence-guided surgery to visualize tumor deposits or SLN biopsy included the data of 410 and 118 patients, respectively. Six studies used indocyanine green tracer with a mean SLN detection rate of 92.3% with a pelvic and para-aortic detection rate of 94.8% and 96.7%, respectively. The sensitivity, specificity, and positive predictive value for micrometastases detection of OTL38 and 5-aminolevulinc acid at time of cytoreduction were 92.2% vs 79.8%, 67.3% vs 94.8%, and 55.8% vs 95.8%, respectively.

CONCLUSION

Fluorescence -guided surgery is a technique that may improve the detection rate of micrometastases and SLN identification in ovarian cancer. Further research is needed to establish whether this will lead to improved patient outcomes.

Where are we going with sentinel nodes mapping in ovarian cancer?

Lymph node involvement is a major predictive indicator in early-stage epithelial ovarian cancer (EOC). There is presently no effective way to determine lymph node involvement other than surgical staging. As a result, traditional ovarian cancer surgery still includes pelvic and paraaortic lymphadenectomy. However, it might be linked to higher blood loss, lengthier operations, and longer hospital stays. The creation of a technique for accurately predicting nodal status without significant lymphadenectomy is thus the subject of ongoing research. Sentinel lymph nodes (SLN) mapping is a routine procedure in oncological surgery and has been proven to be effective and safe in cervical, vulvar, and uterine cancer. On the other hand, SLN mapping is not yet widely accepted and recognized in EOC. A thorough search of the literature was conducted between January 1995 to March 2022, using PubMed and Embase. This review included studies on lymphatic outflow of the ovaries and the sentinel lymph node method. A total of 13 studies involving 212 patients who underwent sentinel lymph node mapping for ovaries were included. Both open and laparoscopic approach are used. The most popular injection site is the ovarian ligaments, and a variety of agents are utilized, although the main markers were, technetium-99m radiocolloid (Tc-99m) or indocyanine green, either alone or in combination. Overall detection rate for SLN in ovaries is 84.5% (interquartile range: 27-100%). We suggest a standardized method for sentinel lymph node mapping in ovarian cancer. The detection rates, characterization and true positive rates of the approach in investigations support further study. The use of ultra-staging is essential for lower-volume metastasis and reproducibility. To ascertain the clinical utility of sentinel node in early ovarian cancer, larger collaborative prospective clinical trials are necessary.

Feasibility of sentinel lymph node mapping in ovarian tumors: A systematic review and meta-analysis of the literature

Purpose of the report

Since the presence of lymph node metastases upstages the disease and to reduce the morbidity of total lymphadenectomy, sentinel lymph node (SLN) mapping in ovarian mass has been the focus of extensive research. This study aims to review all the literature associated with ovarian SLN mapping and assess the feasibility of ovarian SLN mapping.

Materials and methods

PubMed and Scopus were searched using the following keywords: (Sentinel lymph node) AND (Ovary OR Ovarian) AND (Tumor OR Neoplasm OR Cancer). All studies with information regarding sentinel node biopsy in ovaries were included. Different information including mapping material, injection sites, etc., was extracted from each study. In total, two indices were calculated for included studies: detection rate and false-negative rate. Meta-analysis was conducted using Meta-MUMS software. Pooled detection rate, sensitivity, heterogeneity, and publication bias were evaluated. Quality of the studies was evaluated using the Oxford center for evidence-based medicine checklist.

Results

Overall, the systematic review included 14 studies. Ovarian SLN detection rate can vary depending on the type of tracer, site of injection, etc., which signifies an overall pooled detection rate of 86% [95% CI: 75-93]. The forest plot of detection rate pooling is provided (Cochrane Q-value = 31.57, p = 0.003; I2 = 58.8%). Trim and fill method resulted in trimming of 7 studies, which decreased the pooled detection rate to 79.1% [95% CI: 67.1-87.5]. Overall, pooled sensitivity was 91% [59-100] (Cochrane Q-value = 3.93; p = 0.41; I2 = 0%). The proportion of lymph node positive patients was 0-25% in these studies with overall 14.28%.

Conclusion

Sentinel lymph node mapping in ovarian tumors is feasible and seems to have high sensitivity for detection of lymph node involvement in ovarian malignant tumors. Mapping material, injection site, and previous ovarian surgery were associated with successful mapping. Larger studies are needed to better evaluate the sensitivity of this procedure in ovarian malignancies.

Indocyanine Green-Loaded PLGA Nanoparticles Conjugated with Hyaluronic Acid Improve Target Specificity in Cervical Cancer Tumors

PURPOSE

Indocyanine green (ICG) is a promising agent for intraoperative visualization of tumor tissues and sentinel lymph nodes in early-stage gynecological cancer. However, it has some limitations, including a short half-life and poor solubility in aqueous solutions. This study aimed to enhance the efficacy of near-infrared (NIR) fluorescence imaging by overcoming the shortcomings of ICG using a nano-drug delivery system and improve target specificity in cervical cancer.

MATERIALS AND METHODS

ICG and poly(lactic-co-glycolic acid) (PLGA) conjugated with polyethylenimine (PEI) were assembled to enhance stability. Hyaluronic acid (HA) was coated on PEI-PLGA-ICG nanoparticles to target CD44-positive cancer cells. The manufactured HA-ICG-PLGA nanoparticles (HINPs) were evaluated in vitro and in vivo on cervical cancer cells (SiHa; CD44+) and human dermal cells (ccd986sk; CD44-), respectively, using NIR imaging to compare intracellular uptake and to quantify the fluorescence intensities of cells and tumors.

RESULTS

HINPs were confirmed to have a mean size of 200 nm and a zeta-potential of 33 mV using dynamic light scattering. The stability of the HINPs was confirmed at pH 5.0-8.0. Cytotoxicity assays, intracellular uptake assays, and cervical cancer xenograft models revealed that, compared to free ICG, the HINPs had significantly higher internalization by cervical cancer cells than normal cells (p<0.001) and significantly higher accumulation in tumors (p<0.001) via CD44 receptor-mediated endocytosis.

CONCLUSION

This study demonstrated the successful application of HINPs as nanocarriers for delivering ICG to CD44-positive cervical cancer, with improved efficacy in NIR fluorescence imaging.

Sentinel lymph node identification in early stage ovarian cancer: is it still possible after prior tumor resection?

Objective

Sentinel lymph node (SLN) detection in ovarian cancer is feasible when tracers are injected before the pathological ovary is resected. This study aims to investigate whether the SLN identification is also feasible in patients whose ovarian tumor has already been resected with injection of the tracer into the ovarian ligaments stumps, i.e. in the event that a frozen section confirms malignancy.

Methods

Patients who underwent laparotomy with frozen section confirming an ovarian malignancy, and those who underwent a second staging laparotomy after prior resection of a malignant ovarian mass, were included. Blue dye and a radioactive isotope were injected in the stumps of the ligamentum ovarium proprium and the ligamentum infundibulo-pelvicum. After an interval of at least 15-min, the sentinel node(s) were identified using either the gamma-probe and / or blue dye.

Results

A total of 11 patients were included in the study, the sentinel node (SLN) procedure was completed in all 11 patients. At least one SLN was identified in 3 patients, resulting in a rather low detection rate of 27,3%.

Conclusion

In this study we showed that SLN procedure after (previous) resection of the tumor seems inferior to detect sentinel nodes when compared to injection of the tracer in the ovarian ligaments before tumor resection.

Trial registration

NCT02540551

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.

[Sentinel lymph node biopsy in the management of early-stage ovarian cancer: A systematic review of the literature]

The initial management of early-stage ovarian cancer consists of staging surgery including pelvic and para-aortic lymphadenectomy. The use of the sentinel lymph node (SLN) procedure in this setting may decrease the morbidity associated with this surgery. The objective of this review was to evaluate the feasibility of the SLN procedure in ovarian cancer diagnosed at an early stage by comparing the different techniques used and their accuracy. A systematic literature search was performed on PubMed and ClinicalTrials.gov for articles in English or French about the SLN technique in ovarian cancer. Ten studies were included in the analysis, with a total of 179 patients. The main tracers used were Technetium-99m, indocyanine green, and patent blue, and the most common site of injection was the proper ovarian and unfundibulopelvic ligaments. The overall detection rate was 87.7%. Of the small number of cases of lymph node metastasis reported, the SLN procedure had a sensitivity of 90.9% and a negative predictive value of 98.8%. The sentinel node procedure appears to be feasible and safe and could be reliable in determining the lymph node status of patients with early-stage ovarian cancer.

Nanoparticle-based approaches to target the lymphatic system for antitumor treatment

Immunotherapies have been established as safe and efficient modalities for numerous tumor treatments. The lymphatic system, which is an important system, can modulate the immune system via a complex network, which includes lymph nodes, vessels, and lymphocytes. With the deepening understanding of tumor immunology, a plethora of immunotherapies, which include vaccines, photothermal therapy, and photodynamic therapy, have been established for antitumor treatments. However, the deleterious off-target effects and nonspecific targeting of therapeutic agents result in low efficacy of immunotherapy. Fortunately, nanoparticle-based approaches for targeting the lymphatic system afford a unique opportunity to manufacture drugs that can simultaneously tackle both aspects, thereby improving tumor treatments. Over the past decades, great strides have been made in the development of DC vaccines and nanomedicine as antitumor treatments in the field of lymphatic therapeutics and diagnosis. In this review, we summarize the current strategies through which nanoparticle technology has been designed to target the lymphatic system and describe applications of lymphatic imaging for the diagnosis and image-guided surgery of tumor metastasis. Moreover, improvements in the tumor specificity of nanovaccines and medicines, which have been realized through targeting or stimulating the lymphatic system, can provide amplified antitumor immune responses and reduce side effects, thereby promoting the paradigm of antitumor treatment into the clinic to benefit patients.

Ultrastaging protocol in sentinel lymph node for apparent early stage ovarian cancer

OBJECTIVE

The objective of the present study is to determine the role of sentinel lymph node (SLN) ultrastaging in apparent early-stage ovarian cancer.

METHODS

We previously demonstrated the feasibility of SLN in early-stage ovarian cancer in a pilot study and in a clinical trial (NCT03452982). The SLN of the 30 patients involved in both were processed following an ultrastaging protocol. The cost of ultrastaging processing was also reported.

RESULTS

A SLN was detected in up to 91.3% and 90% in the pelvic and para-aortic region, respectively. In all cases, a SLN was detected at least in one field, pelvic or para-aortic. The mean time from injection to SLN resection was 53.3 ± 20.3 min. Two of 30 (6.6%) patients had a contralateral SLN in the para-aortic field, but no patients had contralateral SLN within the pelvic field after injection. The mean number of harvested SLN was 2.1 ± 1.4 (range: 0-5) and 2.7 ± 1.5 (range: 0-7) in the pelvic and para-aortic region, respectively. Two patients were upgraded to stage IIIA1 because of lymph node metastasis. In the first case, based on single sections and haematoxylin and eosin (H&E) examination, a pelvic SLN micrometastasis (1 mm) was found on the first H&E section. By using the ultrastaging protocol, the size of the metastasis was increased to 2.1 mm (macrometastasis). In the same patient, the ultrastaging study of the inframesenteric para-cava SLNs found isolated tumour cells in the subcapsular and interfollicular lymph nodes sinus in one of the two SLN harvested (in one of the sections at the fourth and fifth ultrastage levels). The other upstaged case was a para-aortic macrometastasis in a patient in whom the SLN was not identified in the para-aortic field because of the absence of migration from the infundibulo-pelvic stump injection. The cost of ultrastaging in each patient depended on the total number of SLN retrieved, averaging 96.8 € (range: 0-230.5) and 124.5 € (range: 0-322.7€) for pelvic and para-aortic SLN, respectively.

CONCLUSIONS

A uniform protocol for ultrastaging is essential for lower-volume metastasis detection and to provide reproducible information between upcoming studies, as evidence about SLN in ovarian cancer is growing.

The role of sentinel-node biopsy in ovarian cancer

Lymph node involvement is an important prognostic factor in early and advanced epithelial ovarian cancer (EOC). However, to date there is no reliable method of detecting lymph node involvement, apart from surgical staging. Thus, pelvic and paraaortic lymphadenectomy (LNE) are still part of standard surgery of early ovarian cancer. There is conflicting evidence about the therapeutic value of systematic LNE in early EOC. Thus, the developmemt of a method to predict nodal status accurately, without extensive LNE, is the subject of ongoing research. Sentinel lymphadenectomy (SLN) has become a standard procedure in oncological surgery. However, SLN is not yet an established and widely accepted procedure for EOC. This review aimed at summarizing available evidence on its feasibility and reliability in EOC. Overall, evidence of SLN in early EOC is still scarce. So far, only small series of patients with a variety of tracers and injection sites were published. From the available literature, the most promising technique seems to be injection into the infundibulopelvic, as well as the proper ovarian ligament. Indocyanine green seems to be an excellent tracer for successful SLN of ovarian tumors, which can be used during laparoscopic or robotic surgery. The detection rates and true positive rates of studies support further investigation of the technique. Results from prospective studies, e.g. the ongoing SELLY trial, are necesssary to implement SLN into the standard treatment of early EOC.

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 technique in early-stage ovarian cancer (SENTOV): a phase II clinical trial

Objective

Early-stage ovarian cancer might represent an ideal disease scenario for sentinel lymph node application. Nevertheless, the published experience seems to be limited. Our objective was to assess the feasibility and safety concerns of sentinel lymph node biopsy in patients with clinical stage I–II ovarian cancer.

Methods

We conducted a prospective cohort study of 20 patients with histologically confirmed ovarian cancer. ^99mTc and indocyanine green were injected into both the utero-ovarian and infundibulopelvic ligament stump, if they were present, during surgical staging. An intraoperative gamma probe and near-infrared fluorescence imaging were used to detect the sentinel lymph nodes. Inclusion criteria included: >18 years of age, suspicious adnexal mass (unilateral or bilateral) at ultrasound and CT imaging or confirmed ovarian tumor after previous surgery (unilateral or bilateral salpingo-oophorectomy with or without hysterectomy). Adverse events were recorded through postoperative day 30. The primary trial end point was to report adverse events related to the technique, including the use of ^99mTc and ICG intraperitoneally, as well as the feasibility of the technique.

Results

A total of 20 patients were included in the analysis. Sentinel lymph nodes were detected in 14/15 (93%) pelvic and all 20 (100%) para-aortic regions. Five patients did not have utero-ovarian injection because of prior hysterectomy. The mean time from injection to sentinel lymph node resection was 53±15 min (range; 30–80). The mean number of harvested sentinel lymph nodes was 2.2±1.5 (range; 0–5) lymph nodes in the pelvis and 3.3±1.8 (range; 1–7) lymph nodes in the para-aortic region. There were no adverse intraoperative events, nor any within the 30 days of follow-up related with the technique.

Conclusion

Sentinel lymph node mapping in early-stage ovarian cancer is feasible without major intraoperative or < 30 days safety concerns. (NCT03452982).

Trial registration number

ClinicalTrials.gov, NCT03452982.

Feasibility of sentinel lymph node mapping of the ovary: a systematic review

Pelvic and para-aortic lymphadenectomy is routinely performed in early ovarian cancer to define the stage of the disease. However, it may be associated with increased blood loss, operative time, and length of hospitalization. The sentinel lymph node technique has been shown to be safe and feasible in vulvar, uterine, and cervical cancer. Data detailing feasibility and outcomes of sentinel lymph node mapping in ovarian cancer are scarce.

To summarize the studies evaluating the feasibility of sentinel lymph node detection from the ovary, examining the technique and detection rate.

A systematic search of the literature was performed using PubMed and Embase from June 1991 to February 2019. Studies describing the sentinel lymph node technique and lymphatic drainage of the ovaries were incorporated in this review. Ten articles were selected, comprising a total of 145 patients. A variety of agents were used, but the primary markers were technetium-99m radiocolloid (Tc-99m), patent blue, or indocyanine green, and the most common injection site was the ovarian ligaments.

The overall sentinel lymph node detection rate was 90.3%.

We propose a standardized technique sentinel lymph node mapping in ovarian cancer, using indocyanine green, or Tc-99m and blue dye as alternative tracers, injected in both the suspensory and the infundibulopelvic ligament of the ovary.

The role of sentinel node in early ovarian cancer: a systematic review

INTRODUCTION

Early ovarian cancer (EOC) is defined as ovarian cancer macroscopically limited to the ovaries at the time of initial diagnosis. Approximately only 25% of patients with ovarian cancer are affected by EOC. This condition requires complete surgical staging, including systematic lymphadenectomy up to the level of the renal vessels, with the consequent risk of complications and morbidity. With the aim to reduce the procedure-related morbidity, sentinel lymph node mapping (SLNm) has been introduced as an experimental procedure in EOC staging. The aim of the present study is to systematically review the available series on this interesting issue.

EVIDENCE ACQUISITION

Studies were identified by searching electronic databases. The search was systematically applied to PubMed, ClinicalTrials.gov, Scopus and Web of Science looking for records describing the use of sentinel lymph node technique in EOC from January 1st, 1989 to January 1st, 2019. A total of 10 studies were identified for inclusion. Of the 121 patients involved in these studies, only 43 had a histologically-confirmed diagnosis of EOC and were included in the present analysis.

EVIDENCE SYNTHESIS

SLN (paraaortic and/or pelvic) overall detection rate (DR) was of 97.6%. The overall sensitivity (SS) and negative predictive value (NPV) of the included cases were 66.7% and 96.6%, respectively. We calculated also NPV, SS and DR based on the anatomical lymph node district, with a value of 100% both in the lumbo-aortic and in the pelvic district and a DR of 83.3% and 43% respectively.

CONCLUSIONS

This review shows that evidence on SLNm in EOC is still scant. Based on the limited data available, SLNm may provide potentially useful information on nodal status in patients affected by this disease.

Clinical application of the sentinel lymph node technique in early ovarian cancer: a pilot study

Introduction

There is limited evidence favoring the use of the sentinel lymph node technique in ovarian cancer, and no standardized approach has been studied. The objective of the present pilot study is to determine the feasibility of the sentinel lymph node technique by applying a clinical algorithm.

Methods

Patients with confirmed ovarian cancer were included. 99mTc and indocyanine green were injected into the ovarian and infundubulo-pelvic ligament stump. A gamma probe and near-infrared fluorescence imaging were used for sentinel lymph node detection.

Results

The sentinel lymph node technique was performed in ten patients with a detection rate in the pelvic and/or para-aortic region of 100%. The tracer distribution rates of sentinel lymph nodes in the pelvic and para-aortic regions were 87.5% and 70%, respectively.

Conclusion

The detection of sentinel lymph nodes in early-stage ovarian cancer appears to be achievable. Based on these results, a clinical trial entitled SENTOV (SENtinel lymph node Technique in OVarian cancer) will be performed.

Molecular Imaging of endometrial sentinel lymph nodes utilizing fluorescent-labeled Tilmanocept during robotic-assisted surgery in a porcine model

Molecular imaging with a fluorescent version of Tilmanocept may permit an accurate and facile detection of sentinel nodes of endometrial cancer. Tilmanocept accumulates in sentinel lymph nodes (SLN) by binding to a cell surface receptor unique to macrophages and dendritic cells. Four female Yorkshire pigs underwent cervical stromal injection of IRDye800-Tilmanocept, a molecular imaging agent tagged with near-infrared fluorescent dye and radiolabeled with gallium-68 and technetium-99m. PET/CT scans 1.5 hours post-injection provided pre-operative SLN mapping. Robotic-assisted lymphadenectomy was performed two days after injection, using the FireFly imaging system to identify nodes demonstrating fluorescent signal. After removal of fluorescent nodes, pelvic and periaortic node dissections were performed. Nodes were assayed for technetium-99m activity, and SLNs were established using the “10%-rule”, requiring that the radioactivity of additional SLNs be greater than 10% of the “hottest” SLN. Thirty-four nodal samples were assayed ex vivo for radioactivity. All the SLNs satisfying the “10%-rule” were detected using the FireFly system. Five fluorescent nodes were detected, corresponding with preoperative PET/CT scan. Three pigs had one SLN and one pig had two SLNs, with 100% concordance between fluorescence and radioactivity. Fluorescent-labeled Tilmanocept permits real-time intraoperative detection of SLNs during robotic-assisted lymphadenectomy for endometrial cancer in a porcine model. When radiolabeled with gallium-68, Tilmanocept allows for preoperative localization of SLNs using PET/CT, and shows specificity to SLNs with persistent fluorescent signal, detectable using the FireFly system, for two days post-injection. In conclusion, these findings suggest that a phase I trial in human subjects is warranted, and that a long-term goal of an intra-operative administration of non-radioactive fluorescent-labeled Tilmanocept is possible.

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.

Role of robotic surgery in ovarian malignancy

As part of minimally invasive surgery, robotic-assisted approach is becoming increasingly popular in gynecologic oncology. It has been shown to be effective and feasible for staging and treating endometrial and cervical cancer, but its role in the context of primary and recurrent ovarian cancers is presently debated. Scanty data are available in the literature, and the level of evidence supporting its use in ovarian cancer is quite low. However, from a retrospective case-control series, robotic surgery seems to be safe and feasible for early-stage ovarian cancer. Its use in treating patients with advanced-stage or relapsed ovarian cancer is still highly controversial, suggesting the choice of robotic approach in a highly selected population.