A Pilot Study on the Use of Indocyanine Green Near-Infrared Technique for Sentinel Lymph Node Biopsy in Early Endometrial Cancers in Singapore

Comparing Surgical and Oncological Outcomes between Indocyanine Green (ICG) Sentinel Lymph Node Mapping with Routine Lymphadenectomy in the Surgical Staging of Early-Stage Endometrioid Endometrial Cancer

Methods

A retrospective single-centre cohort study of patients with early-stage endometrioid endometrial cancer undergoing staging surgery (total hysterectomy, bilateral salpingo-oophorectomy with/without pelvic lymph node, and/or para-aortic lymph node dissection (PLND)) with either SLN mapping or routine lymphadenectomy between July 2017 and December 2018.

Results

203 cases with clinical and radiological International Federation of Gynaecology and Obstetrics (FIGO) stage I endometrioid endometrial cancer were included, out of which 109 cases underwent SLN mapping and 94 cases complete lymphadenectomy. Compared to the PLND group, the SLN group had shorter operative time (129 vs. 162 minutes), less blood loss (100 vs. 300 ml), and decreased length of postoperative hospital stay (3 vs. 4 days) (p < 0.001). The lymph node metastases detection rate was 4.6% and 7.4% for the SLN and PLND groups, respectively (p = 0.389). With a median follow-up of 14 months for the SLN and 15 months for the PLND group, the disease-free (DFS) and overall survival (OS) were comparable for both at 13 months (p = 0.538 and p = 0.333, respectively).

Conclusion

SLN mapping has been shown to be an acceptable alternative to routine lymphadenectomy in the surgical staging of early-stage endometrial cancer in our centre, with a comparable lymph node metastases detection rate, DFS and OS, and reduction in operative morbidity. Our results with SLN mapping reproduce comparable outcomes to those reported in the literature.

Sentinel lymph node biopsy in high-grade endometrial cancer: a systematic review and meta-analysis of performance characteristics

OBJECTIVE

A sentinel lymph node biopsy is widely accepted as the standard of care for surgical staging in low-grade endometrial cancer, but its value in high-grade endometrial cancer remains controversial. The aim of this systematic review and meta-analysis was to evaluate the performance characteristics of sentinel lymph node biopsy in patients with endometrial cancer with high-grade histology (registered in the International Prospective Register of Systematic Reviews with identifying number CRD42020160280).

DATA SOURCES

We systematically searched the MEDLINE, Epub Ahead of Print, MEDLINE In-Process & Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Embase databases all through the OvidSP platform. The search was performed between January 1, 2000, and January 26, 2021. ClinicalTrials.gov was searched to identify ongoing registered clinical trials.

STUDY ELIGIBILITY CRITERIA

We included prospective cohort studies in which sentinel lymph node biopsy were evaluated in clinical stage I patients with high-grade endometrial cancer (grade 3 endometrioid, serous, clear cell, carcinosarcoma, mixed, undifferentiated or dedifferentiated, and high-grade not otherwise specified) with a cervical injection of indocyanine green for sentinel lymph node detection and at least a bilateral pelvic lymphadenectomy as a reference standard. If the data were not reported specifically for patients with high-grade histology, the authors were contacted for aggregate data.

METHODS

We pooled the detection rates and measures of diagnostic accuracy using a generalized linear mixed-effects model with a logit and assessed the risk of bias using the Quality Assessment of Diagnostic Accuracy Studies 2 tool.

RESULTS

We identified 16 eligible studies of which the authors for 9 of the studies provided data on 429 patients with high-grade endometrial cancer specifically. The study-level median age was 66 years (range, 44-82.5 years) and the study-level median body mass index was 28.6 kg/m² (range, 19.4-43.7 kg/m²). The pooled detection rates were 91% per patient (95% confidence interval, 85%-95%; I²=59%) and 64% bilaterally (95% confidence interval, 53%-73%; I²=69%). The overall node positivity rate was 26% (95% confidence interval, 19%-34%; I²=44%). Of the 87 patients with positive node results, a sentinel lymph node biopsy correctly identified 80, yielding a pooled sensitivity of 92% per patient (95% confidence interval, 84%-96%; I²=0%), a false negative rate of 8% (95% confidence interval, 4%-16%; I²=0%), and a negative predictive value of 97% (95% confidence interval, 95%-99%; I²=0%).

CONCLUSION

Sentinel lymph node biopsy accurately detect lymph node metastases in patients with high-grade endometrial cancer with a false negative rate comparable with that observed in low-grade endometrial cancer, melanoma, vulvar cancer, and breast cancer. These findings suggest that sentinel lymph node biopsy can replace complete lymphadenectomies as the standard of care for surgical staging in patients with high-grade endometrial cancer.