Sentinel lymph node detection in endometrial cancer: hysteroscopic peritumoral versus cervical injection

Utility of indocyanine green as a single tracer for sentinel node biopsy in endometrial cancer

AIM

Our study aims to investigate the safety and effectiveness of sentinel lymph node biopsy using indocyanine green (ICG) for the surgical staging of early-stage endometrial cancer in comparison to technetium-99 m use.

METHODS

We conducted an observational retrospective study with patients diagnosed of endometrial cancer and FIGO stages I-II. All participants were injected technetium-99m the day prior to the surgery and underwent lymphoscintigraphy along with single-photon emission computed tomography. In addition, all patients were administered intraoperatively ICG injection to detect sentinel lymph node biopsy. The surgical staging was then completed according to the European Society for Medical Oncology preoperative risk category. Data obtained from the analysis of technetium-99m detection was compared to ICG detection.

RESULTS

A total of 53 women with endometrial cancer were included in the study, 49 (92.5%) of them showed drainage preoperatively in the single-photon emission computed tomography and/or lymphoscintigraphy. The intraoperative bilateral detection rate for technetium-99 m was 26 (49.1%) patients compared to 40 (75.5%) patients with ICG (p = 0.013). We observed a 42.5% increase in the mean number of lymph nodes retrieved by ICG compared to technetium-99m (2.85 vs 2,0 nodes; p = 0.002). We intraoperatively identified 164 lymph nodes, 104 (63.4%) located in both obturator areas and external iliac vessels.

CONCLUSION

The use of ICG for the performance of sentinel node biopsy in patients with endometrial cancer seems safe and could be superior to technetium-99 m, since it offers a higher bilateral detection rate and nodal retrieval, resulting in the possibility to perform safely less full staging lymphadenectomies.

The efficiency of a combined injection technique for sentinel lymph node mapping in intermediate-high-risk endometrial cancer

BACKGROUND AND OBJECTIVES

Sentinel lymph node (SLN) mapping was considered for treating endometrial cancer (EC) which was apparent confined to the uterus. Nevertheless, intermediate-high-risk EC patients have super high risk to undergo isolated para-aortic lymph node metastases comparing with low-risk patients. Therefore, this investigation aimed to compare the efficacy of two SLN methods in detecting para-aortic lymph node metastases.

METHODS

According to SLN mapping injection methods, intermediate-high-risk EC patients who received both SLN mapping and systematic lymphadenectomy were divided into the combined group (fundal and cervical injections) and the cervical group (cervical injection only).

RESULTS

The para-aortic SLN detection rate in the combined group (40.4%) was higher than that in the cervical group (4.4%) with p < 0.001. While the differences concerning the sensitivity, false-negative rate, and negative predictive value between the two groups were not significant. The survival outcomes of patients were comparable between the two groups.

CONCLUSION

Our data showcased that the combined (fundal and cervical) injection had a higher detection rate of para-aortic SLNs than cervical injection only. The efficiency of SLN mapping and the survival outcomes were not significantly different between the two groups. Further investigations are warranted to assess the value of combined injection regarding SLN technique.

Sentinel node mapping in endometrial cancer: Tips and tricks to improve bilateral detection rate. The sentitricks study, a monocentric experience

OBJECTIVE

The objective of the study is to show some small tricks for bilateral sentinel lymph node (SLN) uptake in endometrial cancer.

MATERIALS AND METHODS

Each step of the sentinel lymph node technique was analyzed. The cervix was exposed through the use of vaginal valves and by Martin pliers stapling of the anterior cervical lip. Fifty mg Indocyanine Green (ICG) powder was diluted with 10 ml of physiological solution. The spinal needle was marked at 15 mm with a steri-strip. After 20 min from the administration, in case of no LNS identification, an additional 1 ml in the non-detected side was administered in the superficial cervical area. All cervical injections were made by a single (BR) surgeon experienced in oncological gynecology.

RESULTS

Fifty patients undergoing sentinel lymph node research for endometrial cancer. The uptake of at least one side of the sentinel node was 98% (49 cases). Forty-six (92%) patients had bilateral lymph node uptake and 3 patients (6%) had unilateral uptake. Only one patient with pelvic and metastatic aortic lymph nodes had no sentinel nodal uptake.

CONCLUSIONS

Little tricks can increase the bilateral uptake of the SLN up to 92%. The reinjection could be a key element for the success of the SLN technique. Experienced surgeons could certainly play a fundamental role in raising bilateral SLN detection. Further prospective randomized studies are needed to achieve the best SLN infiltration strategy.

[Lymph node management in endometrial cancer]

In 2018, around 382,100 new cases of endometrial cancer (EC) were reported worldwide, accounting for about 4.4% of all new cases of cancer in women. In France, in 2018, the EC is the first gynecological cancer in incidence and the fourth cancer in women. The rationale for the therapeutic management of EC is based on the estimation of a theoretical risk of recurrence and lymph node metastasis using MRI and preoperative biopsy criteria. However, lymph node status remains the determining factor of adjuvant treatment. In order to reduce the morbidity of lymphadenectomy, the concept of sentinel lymph node biopsy (SLN) has been developed. The SLN technique has evolved in recent years, thanks to the advent of robotics and the creation of fluorescence detection cameras. It has been shown that detection of SLN with Indocyanine Green (ICG) allows for more frequent bilateral migration of 88 to 100% and better detection of pelvic GS in 97% of cases with a decrease in morbidity. Recently, in view of the absence of a therapeutic role of lymph node staging, the operational risks and the delay of adjuvant treatments, in case of pelvic lymph node metastasis on definitive histological examination, the question of secondarily performing paraaortic lymphadenectomy arises. The SLN procedure, extended to all early-stage endometrial cancers, should lead to a major reduction in the use of secondary staging and better adaptation of adjuvant therapy.

Performance of sentinel lymph node (SLN) mapping in high-risk endometrial cancer

OBJECTIVE

While the accuracy of the SLN procedure has been validated in patients with low risk EC, its relevance for high-risk EC remains debated. The aim of this study was to evaluate the accuracy of SLN mapping in patients with high-risk EC.

STUDY METHOD

We reviewed all patients with high risk EC (grade 3 endometrioid, serous, carcinosarcoma, clear cell and undifferentiated) who underwent primary surgery with SLN mapping followed by pelvic +/- paraaortic lymphadenectomy, between November 2010 and November 2016.

RESULTS

Among 128 patients who underwent SLN mapping followed by a pelvic lymph node dissection, 41 (32%) had a positive pelvic lymph node. Overall, 48.8% of patients underwent paraaortic node sampling (62/128). Paraaortic lymph node metastasis was identified in 17.7% of patients in whom a para-aortic lymph node dissection was performed (11/62), and all had positive pelvic lymph nodes as well. Successful SLN mapping occurred in 115/128 (89,8%) patients, with a bilateral detection rate at 63.2% (81/128). Positive SLNs were identified in 30.4% of patients (39/128) including 7 isolated tumor cells (ITC), 4 micrometastasis and 28 macrometastasis. When the SLNs were detected bilaterally, only one false negative case occurred, providing a sensitivity and negative predictive value of 95.8% and 98.2% respectively.

CONCLUSION

Accurate surgical staging is an important prognostic predictor of survival in patients with endometrial cancer. Given the high sensitivity and high negative predictive value found in our study, we believe that the use of SLN mapping appears to be an appropriate staging procedure in high-risk endometrial cancer.

Laparoscopic Sentinel Node Mapping in Endometrial Cancer After Hysteroscopic Injection of Indocyanine Green

STUDY OBJECTIVE

To report the detection rate (DR) of sentinel lymph nodes (SLNs) in endometrial cancer (EC) patients after hysteroscopic injection of indocyanine green (ICG) and laparoscopic near-infrared (L-NIR) fluorescence mapping.

DESIGN

Prospectively collected data (Canadian Task Force classification II-2).

SETTING

Gynecologic oncology referral center.

PATIENTS

Consecutive patients with apparent early-stage endometrioid EC scheduled for surgical treatment: total laparoscopic hysterectomy, bilateral salpingo-oophorectomy, SLN mapping.

INTERVENTIONS

The mapping technique consisted in an intraoperative hysteroscopic peritumoral injection of 5 mg ICG followed by L-NIR fluorescence mapping. Evaluations of the SLN DR and sites of mapping were performed.

MEASUREMENTS AND MAIN RESULTS

A total of 57 procedures was performed. Patient mean age was 60 years (range, 28-80) and mean body mass index was 28.2 kg/m² (range, 19-43). At least 1 SLN was detected in 89.5% of the whole population (51/57). After the first 16 cases, L-NIR camera technical improvement led to a 95% DR (39/41). The mean number of harvested SLNs was 4.1 (range. 1-8), and in 47% of cases SLNs mapped to aortic nodes (24/51). Bilateral pelvic mapping was found in 74.5% of cases (38/51). Three patients had SLN metastases: 1 in the pelvic area only, 1 both in the pelvic and aortic area, and 1 presented with 2 metastatic aortic SLNs with negative pelvic SLNs. Overall, 2 of 3 node-positive patients (67%) had aortic SLN involvement. No adverse events were reported.

CONCLUSIONS

Laparoscopic SLN mapping after the hysteroscopic injection of ICG has comparable DRs with both radioactive tracer series and ICG series with cervical injection, overcoming the need for radioactive substances. Hysteroscopic injection leads to a higher mapping in the aortic area compared with cervical injection. Further investigation is warranted on this topic.