Sentinel Node and Ovarian Tumors: A Series of 20 Patients

Contribution of the cadaveric recirculation system in the anatomical study of lymphatic drainage of the ovary: applications in the management of ovarian cancer

PURPOSE

The present knowledge about lymphatic drainage of the ovary is based on carcinological studies, but it has only rarely been studied under physiological conditions. However, it is one of the preferential routes of dissemination in ovarian cancer, and understanding it is therefore vital for optimal carcinological management.Our purpose was to evaluate the feasibility of an innovative technique to study the lymphatic drainage territories of the ovary using a recirculation module on the cadaveric model.

METHODS

We injected patent blue into the cortex of twenty "revascularised" cadaver ovaries with the Simlife recirculation model. We observed the migration of the dye live and described the drainage territories of each ovary.

RESULTS

We observed a staining of the lymphatic vessels and migration of the dye in all the subjects, systematically ipsilateral to the injected ovary. We identified a staining of the lumbo-aortic territory in 65% of cases, with a preferential lateral-caval involvement (60%) for the right ovary and lateral-aortic territory (40%) for the left ovary. A common iliac involvement was observed in only 10% of cases. In 57% of cases, the staining of the lumbo-aortic territory was associated with a staining of the suspensory ligament. The pelvic territory was involved in 50% of cases, with an external iliac staining in 25% of cases and internal in 20%.

CONCLUSION

Our study provides for a better understanding of lymphatic drainage of the ovary using a new detection method, and allows the possibility of improving the teaching for operators with a realistic model. Continuation of this work could lead to considering more targeted and thus less morbid lymph node sampling for lymph node staging in early-stage ovarian cancer.

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.

Molecular image-guided surgery in gynaecological cancer: where do we stand?

PURPOSE

The aim of this review is to give an overview of the current status of molecular image-guided surgery in gynaecological malignancies, from both clinical and technological points of view.

METHODS

A narrative approach was taken to describe the relevant literature, focusing on clinical applications of molecular image-guided surgery in gynaecology, preoperative imaging as surgical roadmap, and intraoperative devices.

RESULTS

The most common clinical application in gynaecology is sentinel node biopsy (SNB). Other promising approaches are receptor-target modalities and occult lesion localisation. Preoperative SPECT/CT and PET/CT permit a roadmap for adequate surgical planning. Intraoperative detection modalities span from 1D probes to 2D portable cameras and 3D freehand imaging.

CONCLUSION

After successful application of radio-guided SNB and SPECT, innovation is leaning towards hybrid modalities, such as hybrid tracer and fusion of imaging approaches including SPECT/CT and PET/CT. Robotic surgery, as well as augmented reality and virtual reality techniques, is leading to application of these innovative technologies to the clinical setting, guiding surgeons towards a precise, personalised, and minimally invasive approach.

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.

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.

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

[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.

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.

Lymphadenectomy in the Management of Gynecologic Cancer

Among nearly all gynecologic cancers, knowing whether the cancer has metastasized to lymph nodes impacts the ultimate management of the cancer. Lymph node status assists in cancer staging, prognostication, guidance of surgical intervention and adjuvant therapy, and removal of positive lymph nodes may be therapeutic in some cancers. Surgical staging through lymph node removal and pathologist assessment is standard of care for most gynecologic cancers. This section reviews the anatomic lymphatic drainage patterns of each gynecologic organ and the evolution and current practice of surgical lymph node assessment along the spectrum of gynecologic cancers.

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.