Sentinel node mapping using indocyanine green and near-infrared fluorescence imaging technology for endometrial cancer: A prospective study using a surgical algorithm in Indian patients

Risk factors associated with false negative rate of sentinel lymph node biopsy in endometrial cancer: a systematic review and meta-analysis

Objective

Currently, sentinel lymph node biopsy (SLNB) is increasingly used in endometrial cancer, but the rate of missed metastatic lymph nodes compared to systemic lymph node dissection has been a concern. We conducted a systematic review and meta-analysis to evaluate the false negative rate (FNR) of SLNB in patients with endometrial cancer and to explore the risk factors associated with this FNR.

Data sources

Three databases (PubMed, Embase, Web of Science) were searched from initial database build to January 2023 by two independent reviewers.

Research eligibility criteria

Studies were included if they included 10 or more women diagnosed with International Federation of Gynecology and Obstetrics (FIGO) stage I or higher endometrial cancer, the study technique used sentinel lymph node localization biopsy, and the reported outcome metrics included false negative and/or FNR.

Study appraisal and synthesis methods

Two authors independently reviewed the abstracts and full articles. The FNR and factors associated with FNR were synthesized through random-effects meta-analyses and meta-regression.

The results

We identified 62 eligible studies. The overall FNR for the 62 articles was 4% (95% CL 3-5).There was no significant difference in the FNR in patients with high-risk endometrial cancer compared to patients with low-risk endometrial cancer. There was no difference in the FNR for whether frozen sections were used intraoperatively. The type of dye used intraoperatively (indocyanine green/blue dye) were not significantly associated with the false negative rate. Cervical injection reduced the FNR compared with alternative injection techniques. Indocyanine green reduced the FNR compared with alternative Tc-99m. Postoperative pathologic ultrastaging reduced the FNR.

Conclusions

Alternative injection techniques (other than the cervix), Tc-99m dye tracer, and the absence of postoperative pathologic ultrastaging are risk factors for a high FNR in endometrial cancer patients who undergo SLNB; therefore, we should be vigilant for missed diagnosis of metastatic lymph nodes after SLNB in such populations.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023433637.

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.

Recent Progress in Second Near-Infrared (NIR-II) Fluorescence Imaging in Cancer

Cancer continues to be one of the leading causes of death worldwide, and its incidence is on the rise. Although cancer diagnosis and therapy have advanced significantly in recent decades, it is still a challenge to achieve the accurate identification and localization of cancer and to complete tumor elimination with a maximum preservation of normal tissue. Recently, second near-infrared region (NIR-II, 1000-1700 nm) fluorescence has shown great application potential in cancer theranostics due to its inherent advantages, such as great penetration capacity, minimal tissue absorption and scattering, and low autofluorescence. With the development of fluorescence imaging systems and fluorescent probes, tumor detection, margin definition, and individualized therapy can be achieved quickly, enabling an increasingly accurate diagnosis and treatment of cancer. Herein, this review introduces the role of NIR-II fluorescence imaging in cancer diagnosis and summarizes the representative applications of NIR-II image-guided treatment in cancer therapy. Ultimately, we discuss the present challenges and future perspectives on fluorescence imaging in the field of cancer theranostics and put forward our opinions on how to improve the accuracy and efficiency of cancer diagnosis and therapeutics.

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

Objective

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

Methods

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

Results

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

Conclusion

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