Indocyanine green fluorescence imaging of lymph nodes during robotic-assisted laparoscopic operation for endometrial cancer. A prospective validation study using a sentinel lymph node surgical algorithm.

OBJECTIVE: A sentinel lymph node (SLN) strategy may have particular value in endometrial cancer (EC) because a therapeutic effect of lymphadenectomy per se is unproven. The aim was to evaluate indocyanine green (ICG) and near-infrared (NIR) fluorescence mapping using a surgical algorithm.

METHODS: From November 2012 through December 2015, women with apparently early stage EC underwent robot-assisted laparoscopic hysterectomy including ICG fluorescence SLN mapping following the Memorial Sloane Kettering Cancer Center (MSKCC) surgical algorithm.

RESULTS: Among 108 patients included, ≥1 SLNs was identified in 104 (96%), bilaterally in 84 (78%) and unilaterally in 20 patients (18%). Four patients failed SLN mapping. All SLN-positive patients had pelvic SLNs. Median number of nodes were 4.0 and 6.0 (p<0.001), when SLNs only and SLNs plus non-SLNs were removed, respectively. Lymph node metastases were detected in 17 patients (16%). One patient who failed SLN mapping had a non-SLN metastasis. The remaining 16 patients had metastases in SLNs, 12 in SLNs only and four in both SLNs and non-SLNs. Routine pathology detected 75% of patients with cancer positive SLNs while 25% were based on extended pathology. Lymph node metastases were found among 9% with low-, 11% with intermediate- and 32% with high-risk profiles, respectively.

CONCLUSIONS: We have reproduced the high total and bilateral SLN mapping using cervical ICG injection and NIR fluorescence. Practical application of the MSKCC algorithm allowed high lymph node metastasis detection in combination with a low extent of lymph node removal.