Methods
After institutional board review approval, all patients with clinical
stage I endometrial cancer who underwent either robot-assisted or
laparoscopic total hysterectomy from our institution were
retrospectively selected from 2016-2020. Clinical stage I endometrial
cancer was determined by preoperative physical exam and imaging. The
decisions to perform surgery robotically verses laparoscopically was
based on surgeon preference. Patients with endometrioid, uterine
papillary serous (UPSC), malignant mixed mesodermal tumor (MMMT), and
clear cell (CC) histologic subtypes were included.
Indocyanine green was reconstituted per the manufacturer’s directions
and injected into the cervix bilaterally at 3 and 9 o’clock both
superficially (submucosally) and deep (1 cm into the stroma). Sentinel
nodes were identified using near-infrared technology. Patients with
suboptimal lymph node mapping or nodes suspicious for metastasis during
surgical evaluation underwent a side specific pelvic lymph node
dissection (LND). Paraaortic LND was performed at the discretion of the
surgeon. In addition to SLNB, complete pelvic and paraaortic lymph node
dissection (PPALND) was performed for patients with the following
high-risk histologic subtypes: UPSC, CC and MMMT. SLNs were then
evaluated by gynecologic pathologists using ultra-staging protocols
including serial sectioning and cytokeratin staining. The medical record
was queried for clinical or radiographic evidence of recurrence; median
follow up was 22 months for this cohort.
The primary objective was to evaluate the accuracy and sensitivity of
SLN mapping at our university affiliated community-based institution. In
addition, rates of SLN detection were evaluated over 3 years to chart
potential improvements over time as correlating to surgeon experience.
Descriptive statistics, such as frequency distribution, mean, median,
interquartile range, minimum and maximum were calculated for relevant
variables. To compare successful mapping rates at our institution to
those in the literature a one sample test of proportion was performed.
Chi square and Fisher’s Exact test were performed to determine whether
successful mapping rates among patients was related to patient specific
factors such as BMI as well as pathologic factors such as the presence
of uterine leiomyoma, adenomyosis, lymphovascular space invasion and
tumor depth of invasion (<50% vs. > 50%).