A commentary on “Comparison of different tracers in sentinel lymph node detection for endometrial cancer: a systematic review and network meta-analysis”

Dear Editor,

Endometrial cancer is one of the most prevalent malignant tumors of the female reproductive system, mostly affects postmenopausal women^[1,2]. The use of hormone replacement medication, obesity, and changes in lifestyle are the primary causes of the steadily rising prevalence of endometrial cancer worldwide. In 2020, there were nearly 90 000 deaths and 380 000 new cases of endometrial cancer globally, according to data from the World Health Organization. To reduce the rate of needless lymphadenectomy in low-risk women and the risk of under-staging and, consequently, under-treatment, sentinel lymph node (SLN) biopsy – a technique that has transformed the approach to lymph node evaluation in many other cancer types – has been suggested for endometrial cancer surgery^[3]. There is still disagreement, nevertheless, over which tracers are best for this process. To identify the best combination that produces the greatest detection rate, Feng et al^[4] conducted a network meta-analysis and systematic review. This analysis includes 11 trials with 2,699 participants. According to pooled data, the most effective technique in terms of both bilateral and total detection rates was the combination of indocyanine green (ICG) and radioactive isotopes. Furthermore, carbon nanoparticles (CNPs) outperformed other methods in identifying para-aortic lymph nodes.

With the development of minimally invasive surgery in recent years, ICG has been used in a number of applications, including cardiac output measurement, choroidal blood flow evaluation, and hepatic blood flow assessment. ICG is a fluorescent dye that is often used in clinical practice due to its low cost. ICG provides real-time visual assistance for lymphatic channel imaging, and has few adverse effects. ICG outperforms other tracers in terms of both bilateral and total detection rates, according to a previous meta-analysis. It is crucial to note that ICG has some restrictions in spite of this. One crucial point is that the final pathology only identifies adipose tissue and not lymph nodes when excising tissue is scanned by ICG. ICG’s rapid diffusion and ability to move swiftly through the SLN to secondary and tertiary lymph nodes is another drawback. This might result in surgeons unintentionally excising nonsentinel lymph nodes. Additionally, ICG has a poor detection probability in obese patients due to its restricted capacity to permeate tissue. ICG must be injected intraoperatively to take advantage of its rapid lymphatic drainage since, in contrast to radiotracers, it is not retained by macrophages inside the lymph nodes. This feature makes it impossible to obtain preoperative lymphatic mapping, which is essential for surgical planning.

It should be noted that the included studies did not offer effective information on different injection locations. In addition, this study did not address the impact of injection sites on the effectiveness of SLN biopsy. The effectiveness of different tracers in SLN biopsies might be further supported by well-designed RCTs to provide more reliable recommendations for clinical practice.

This study is compliant with the TITAN Guidelines 2025^[5].

Ethical approval

Not applicable.

Consent

Not applicable.

Sources of funding

None.

Author contributions

H.W.: writing; P.Z.: data collections; N.W.: study design.

Conflicts of interest disclosure

None.

Research registration unique identifying number (UIN)

Not applicable.

Guarantor

Huansheng Wang.

Provenance and peer review

Not applicable.

Data availability statement

Not applicable.