Impact of Obesity on Sentinel Lymph Node Mapping in Patients with Newly Diagnosed Uterine Cancer Undergoing Robotic Surgery

Purpose: The aim of this study was to determine the impact of obesity on the rate of successful sentinel lymph node (SLN) mapping in patients with uterine cancer undergoing robotic surgery, and compare SLN detection rates using indocyanine green (ICG) versus blue dye.

Methods: We reviewed robotic cases undergoing SLN mapping with a cervical injection from January 2011 to December 2013 using either blue dye or ICG with near-infrared (NIR) fluorescence imaging. Data were stratified by body mass index (BMI) and the dye used. Appropriate statistical tests were applied.

Results: Overall, 472 cases were identified. Bilateral mapping was successful in 352 cases (75 %), and unilateral mapping was successful in 73 cases (15 %). Bilateral mapping was achieved in 266 (85 %) of 312 ICG cases compared with 86 (54 %) of 160 blue-dye cases (p < 0.001). Cases with successful bilateral mapping had a median BMI of 29.8 kg/m(2) (range 16.3-65.3 kg/m(2)); cases with no mapping had a median BMI of 34.7 kg/m(2) (range 21.4-60.4 kg/m(2)) (p = 0.001). With increasing BMI, there was a significant decrease in successful bilateral mapping rates for both the ICG (p < 0.001) and blue-dye groups (p = 0.041); however, the use of ICG resulted in better bilateral (p = 0.002) and overall (p = 0.011) mapping rates compared with the use of blue dye in all BMI groups.

Conclusions: ICG results in a higher overall and bilateral SLN detection than blue dye in women with uterine cancer. Successful mapping decreases with increasing BMI irrespective of the dye used; however, it is significantly improved with the use of ICG and NIR fluorescence imaging compared with blue dye.