Ultrastaging protocol in sentinel lymph node for apparent 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.

Sentinel-node biopsy in apparent early stage ovarian cancer: final results of a prospective multicentre study (SELLY)

AIM

To evaluate the sensitivity and specificity of sentinel-lymph-node mapping compared with the gold standard of systematic lymphadenectomy in detecting lymph node metastasis in apparent early stage ovarian cancer.

METHODS

Multicenter, prospective, phase II trial, conducted in seven centers from March 2018 to July 2022. Patients with presumed stage I-II epithelial ovarian cancer planned for surgical staging were eligible. Patients received injection of indocyanine green in the infundibulo-pelvic and, when feasible, utero-ovarian ligaments and sentinel lymph node biopsy followed by pelvic and para-aortic lymphadenectomy was performed. Histopathological examination of all nodes was performed including ultra-staging protocol for the sentinel lymph node.

RESULTS

174 patients were enrolled and 169 (97.1 %) received study interventions. 99 (58.6 %) patients had successful mapping of at least one sentinel lymph node and 15 (15.1 %) of them had positive nodes. Of these, 11 of 15 (73.3 %) had a correct identification of the disease in the sentinel lymph node; 7 of 11 (63.6 %) required ultra-staging protocol to detect nodal metastasis. Four (26.7 %) patients with node-positive disease had a negative sentinel-lymph-node (sensitivity 73.3 % and specificity 100.0 %).

CONCLUSIONS

In a multicenter setting, identifying sentinel-lymph nodes in apparent early stage epithelial ovarian cancer did not reach the expected sensitivity: 1 of 4 patients might have metastatic lymphatic disease unrecognized by sentinel-lymph-node biopsy. Nevertheless, 35.0 % of node positive patients was identified only thanks to ultra-staging protocol on sentinel-lymph-nodes.

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.

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.

Utilization of sentinel lymph node biopsy in the early ovarian cancer surgery

OBJECTIVE

Sentinel lymph node (SLN) biopsy has been incorporated into surgical care for many malignancies; however, the utility has not been examined in ovarian cancer. This study examined population-level trends, characteristics, and outcomes related to SLN biopsy in early stage ovarian cancer.

METHODS

This is a retrospective cohort study querying the National Cancer Institute's Surveillance, Epidemiology, and End Result Program from 2003-2018. The study population consisted of 11,512 women with stage I ovarian cancer who had adnexectomy-based surgical staging including lymph node evaluation. Exposure allocation was based on SLN biopsy use. Main outcomes measured were (i) trends and characteristics associated with SLN biopsy use, assessed by multivariable logistic regression model, and (ii) overall survival assessed with inverse provability of treatment weighting propensity score.

RESULTS

SLN biopsy was performed in less than 1% of study population. In a multivariable analysis, recent surgery (2011-2018 versus 2003-2010, odds ratio [OR] 1.64, 95% confidence interval [CI] 1.03-2.59), smaller tumor size (< 10 versus ≥ 10 cm, OR 3.07, 95% CI 1.20-7.84), and East registry area (OR 2.74, 95% CI 1.73-4.36) remained independent characteristics for SLN biopsy use. In a propensity score weighted model, 5-year overall survival rate was 90.5% for the SLN biopsy-incorporated group and 88.6% for the lymphadenectomy group (hazard ratio 0.96, 95% CI 0.53-1.73).

CONCLUSION

SLN biopsy was rarely performed for early ovarian cancer surgery during the study period with insufficient evidence to interpret the survival effect. SLN biopsy in early ovarian cancer appears to be in early development phase, warranting further study and careful evaluation to assess feasibility and oncologic outcome.

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.

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.

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