Introduction Fluorescence image-guided sentinel lymph node (SLN) biopsy using a two-step mapping technique incorporates sequential injection of indocyanine green into the bilateral uterine cornus, followed by cervical injection. Outcomes were compared with the conventional cervical (one-step) method .
Methods Patients with FIGO stage I-III endometrial cancer who underwent laparoscopic or robotic staging, including SLN biopsy, from May 2014 to December 2018, were retrospectively reviewed. Patient characteristics, pre-operative imaging, SLN detection pattern, pathologic result, adjuvant, and recurrence locations were analyzed.
Results A total of 199 patients received one-step (n=123) and two-step (n=76) SLN biopsy. Para-aortic SLN were more frequently identified in the two-step group. Lower and upper para-aortic SLN were identified in 67.1% and 38.2%, respectively, in the two-step group and in 18.7% and 5.7% in the one-step group (p<0.001). The number of para-aortic SLN harvested was superior in the two-step group (p<0.001). Metastatic para-aortic SLN were found in 7.9% of the two-step group and 2.4% of the one-step group (p=0.070). In detecting nodal metastasis, the sensitivities of the one- and two-step methods were 91.7% and 100.0%, negative predictive values were 99.0% and 100.0%, false-negative rates were 8.3% and 0%, and accuracy rates were 99.1% and 100.0%, respectively. The one-step method identified only three out of eight para-aortic lymph node metastases and missed five para-aortic lymph node metastases. There was no missed para-aortic lymph node metastasis in the two-step group. Recurrence was observed in two patients (2.6%; vaginal vault and adrenal gland) in the two-step group and seven patients (5.7%) including three nodal recurrences in the one-step group (p=0.307).
Discussion Two-step SLN mapping improved the para-aortic SLN detection rate, a known pitfall of conventional cervical injection. Proper evaluation of aortic nodal status will assist in the tailoring of adjuvant and prevent undertreatment of patients with isolated para-aortic metastasis.
- endometrial neoplasms
- sentinel lymph node
- lymphatic metastasis
- neoplasm recurrence, local
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Editor's note This paper will feature in a special issue on sentinel lymph node mapping in 2020.
Contributors All authors contributed to the writing of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information. The data are not published elsewhere. Data are available upon reasonable request.
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